SYSTEM FOR GENERATING SUPERHEATED STEAM USING HYDROGEN PEROXIDE
20170248305 · 2017-08-31
Inventors
Cpc classification
E21B43/2405
FIXED CONSTRUCTIONS
B01J2219/00259
PERFORMING OPERATIONS; TRANSPORTING
F22B3/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B01J8/00
PERFORMING OPERATIONS; TRANSPORTING
E21B37/00
FIXED CONSTRUCTIONS
F22G1/14
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F22G1/14
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
E21B37/00
FIXED CONSTRUCTIONS
Abstract
The invention relates to a system for generating superheated steam using hydrogen peroxide, formed by: a container for storing hydrogen peroxide, which stores a solution of peroxide that is used during the reaction to generate superheated steam; a hydrogen peroxide discharge pump connected to a first connecting duct, said discharge pump being used to pump the hydrogen peroxide solution to a reaction container via a second connecting duct; and a steam generating reaction container or reactor, in which the reaction takes place and the superheated steam is generated, said reaction container or reactor receiving the hydrogen peroxide solution in order for the reaction to take place and the superheated steam to be generated and subsequently conveyed through a nozzle and an outlet duct towards installations that are to undergo cleaning and/or stimulation.
Claims
1. A system for generating superheated steam using hydrogen peroxide comprising a hydrogen peroxide storage container, wherein a peroxide solution is stored which is used during the reaction to generate the superheated steam; a hydrogen peroxide discharge pump which is interconnected to the storage container by a first interconnection duct, the discharge pump being used to pump the hydrogen peroxide solution into a reaction container by a second interconnection duct; a steam generator reaction container or reactor wherein the reaction is carried out and the superheated steam is generated, which receives the hydrogen peroxide solution for the reaction to take place and the superheated steam is generated, to be sent through a nozzle and an outlet duct, to the facilities that will be subjected to cleaning and/or stimulation.
2. The system for generating superheated steam using hydrogen peroxide of claim 1, wherein the reaction container or reactor includes a reaction chamber therein, wherein a plurality of reactants is placed, which are pre-loaded prior to initiating the reaction with the hydrogen peroxide; as well as a nozzle and a venting duct, to allow the gases to escape during the reaction, or in case of emergency.
3. The system for generating superheated steam using hydrogen peroxide of claim 1, wherein for the interconnection between the system for generating superheated steam and the installations which will be subjected to cleaning and/or stimulation, at least one interconnection duct is used.
4. The system for generating superheated steam using hydrogen peroxide of claim 1, wherein the system for generating superheated steam further has a control panel which is interconnected to a system of peroxide injection to regulate the supply flow of peroxide solution to the reaction container, as well as to the discharge pump motor to operate and/or stop the pump in case of emergency; in addition to having at least a couple of temperature and pressure indicators.
5. The system for generating superheated steam using hydrogen peroxide of claim 1, wherein to facilitate the transfer of the system for generating superheated steam to the site where the cleaning and/or stimulation procedure will be performed, its components are fixed on a platform or structural skid, being by its dimensions a compact and portable system, that for its transfer requires an automotive vehicle whose capacity is at least 1.5 tons or a trailer whose capacity is at least of 3 tons.
6. The system for generating superheated steam using hydrogen peroxide of claim 1, wherein the hydrogen peroxide solution required for the superheated steam generation is stored in the storage container in a concentration ranging from 30% to 70% by weight.
7. The system for generating superheated steam using hydrogen peroxide of claim 2, wherein the plurality of compounds or reactants which react with the hydrogen peroxide are contained as blocks within the reaction chamber and have a lifespan of up to 10 interventions or 15 continuous hours of operation, whichever occurs first.
8. The system for generating superheated steam using hydrogen peroxide of claim 7, wherein in the reaction chamber, three reactants are used: hydrogen peroxide (H.sub.2O.sub.2) in the range of 30% to 70% % by weigh; and, a block of potassium permanganate (KMnO.sub.4) as catalyst precursor and sucrose (C.sub.12H.sub.22O.sub.11) as organic fuel.
9. The system for generating superheated steam using hydrogen peroxide of claim 8, wherein the hydrogen peroxide reacts with the potassium permanganate to form the manganese dioxide, which functions as catalyst of the reaction, by continuing the reaction and contacting the sucrose, a violent reaction occurs which generates steam and pure oxygen at elevated temperature, which can reach up to 400° C. (752° F.), depending on the conditions and quantities of reactants used.
10. The system for generating superheated steam using hydrogen peroxide of claim 9, wherein compounds selected from: manganese oxide IV or manganese dioxide (MnO.sub.2), iron oxide II (Fe.sub.2O.sub.3), calcium oxide (CaO), lead oxide (PbO.sub.2), calcium hydroxide (Ca(OH).sub.2, aluminum oxide (Al.sub.2O.sub.3), copper oxide II (CuO), copper oxide II (Cu.sub.2O), potassium chromate (K.sub.2CrO.sub.4), potassium dichromate (K.sub.2Cr.sub.2O.sub.7), copper sulphate (CuSO.sub.4), among others, can also be used as catalysts for the catalytic decomposition of hydrogen peroxide.
11. The system for generating superheated steam using hydrogen peroxide of claim 8, wherein gasoline and/or coal dust can also be used as organic fuel.
12. The system for generating superheated steam using hydrogen peroxide of claim 9, wherein the reaction with the organic fuel allows temperatures ranging from 80° C. to 180° C. to be reached at a concentration of 30% to 50% by weight of hydrogen peroxide and from 80° C. to 400° C. at a concentration from 50% to 70% by weight of hydrogen peroxide, on a pressure scale up to 3000 psi.
13. The system for generating superheated steam using hydrogen peroxide of claim 12, wherein the superheated steam obtained has a steam quality of 100% with no water droplets in suspension and a negligible oxygen concentration, further no emission of greenhouse gases is generated from the burning of fossil fuels, no waste contaminants is generated, no fire hazards, the crude is not contaminated, nor the pipes are corroded
14. The system for generating superheated steam using hydrogen peroxide of claim 13, wherein the superheated steam is used for the injection and/or stimulation of oil fields (wells), as well as for the cleaning of oil installations such as pipelines, heads, discharge lines, separation batteries, coolers, production wells, heat exchangers, tanks, refineries, coke treatments, fluid mobility, etc., achieving arrive by the temperature profile obtained, to a greater depth, by obtaining higher temperature differentials than those existing in the well and consequently a greater effectiveness in the cleaning of riggings and/or process equipment.
15. The system for generating superheated steam using hydrogen peroxide of claim 1, wherein the system is fully portable and of instantaneous steam generation, which allows to move the system to any remote installation, further is not required special adaptations for their interconnection in wells and/or installations, nor water is required for the steam generation or ignition gas to generate steam.
16. The system for generating superheated steam using hydrogen peroxide of claim 15, wherein the system can be applied in horizontal wells, as the superheated steam never loses its gas phase condition, which allows the intervention of wells in which have been carried out fractures and horizontal multi-fractures, as well as the techniques of“fracking”, as well as wells with horizontal terminations
17. The system for generating superheated steam using hydrogen peroxide of claim 14, wherein the application of the system for generating superheated steam during the well stimulation, allows obtaining steam injection times from 30 minutes to 3 hours, well shutdown time of one day and incremental production time from 3 weeks to 3 months.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0070] The configuration and elements of the system for generating superheated steam using hydrogen peroxide can be seen in the following indicated figures, wherein a particularly preferred embodiment of the invention is shown, which is to be considered as illustrative only, but not limiting thereof, wherein:
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DETAILED DESCRIPTION OF THE INVENTION
[0079] Referring now to the accompanying drawing, and more specifically to
[0080] The system for generating superheated steam 10 is conformed of a hydrogen peroxide storage container 11, preferably a tank, wherein the peroxide solution to be used during the reaction is stored; a hydrogen peroxide discharge pump 13 which is interconnected to the storage container 11 by a first interconnection duct 12, the discharge pump 13 being used to pump the hydrogen peroxide solution to a reaction container 15 by a second interconnection duct 14; a steam generating reaction container 15, preferably a reaction tank or reactor, which receives the hydrogen peroxide solution to effect the reaction with a plurality of compounds or reactants which are previously loaded into a reaction chamber, wherein the reaction is carried out and the superheated steam is generated, which once generated exits through an outlet nozzle to be sent by the outlet duct 16 to the facilities 21 to be cleaned, preferably oil installations. The reaction container 15 further has a venting nozzle to which a duct 17 is interconnected to allow the exhaust of gases during the reaction or in emergency event.
[0081] To perform the interconnection between the system for generating superheated steam 10 and the installations 21 to be cleaned, at least one interconnection duct 22 is used.
[0082] The system for generating superheated steam 10 further has a control panel 18, which is interconnected to a peroxide injection system 19, for regulating the supply flow of peroxide solution to the reaction tank 15; and to the motor 20 of the discharge pump 13 to operate and stop the pump in case of emergency (emergency stop). Also, the control panel 10 has at least one pair of temperature and pressure indicators.
[0083] To facilitate the transfer of the system for generating superheated steam 10 to the site where the steam cleaning procedure is carried out, its components are fixed on a platform or structural skid to be incorporated into a trailer.
[0084] The system for generating superheated steam of the present invention, due to its structural characteristics, is a compact and portable system which for its field operation only requires a crew of two to three persons, and can be easily transportable in an automotive vehicle (Platform or pick-up truck) with a capacity of at least 1.5 tons, or on a trailer of at least 3000 kg (6613 lbs.).
[0085] The hydrogen peroxide solution required for the superheated steam generation is stored in the storage container 11 in a concentration ranging from 30% to 70% by weight, it being possible to use plastic materials such as IBC totes, with capacity of at least 1000 liters with a 2-inch valve and metal base for peroxide of up to 50% concentration, or stainless steel containers, depending on the peroxide concentration.
[0086] The discharge pump 13 in a preferred embodiment is designed to operate at a discharge pressure of up to 9,000 psi pressure, not to be limited to these operating and design conditions, since different capacities may be used, depending on the design of the intervention and the required steam volumetry.
[0087] The discharge pump motor 13 may be an internal combustion engine which uses gasoline or diesel, or it may be an electric motor using alternating current or direct current, which may be powered by a battery pack or may be connected to the local electricity distribution network.
[0088] The steam generating reaction container 15 contains therein as already mentioned a plurality or set of reactants which react with the hydrogen peroxide to carry out the exothermic reaction necessary for the gaseous effluents production. The set of reactants are contained as blocks within a reaction chamber (not shown in the figure). The reactant blocks have a useful life of up to 10 interventions or 15 continuous operation hours, whichever comes first.
[0089] The steam generating reaction container 15 has an outlet nozzle to which the outlet duct 16 is interconnected (preferably using a hose), further including a shutoff and opening valve (preferably using a ball valve); and, a venting nozzle which interconnects a vent valve to the atmosphere. In a further embodiment, the venting nozzle includes a locking valve.
[0090] The first interconnecting duct 12 may be a flexible tubing or hose designed to operate at low pressure; while the second interconnection duct 14 and the outlet duct 16 may be a flexible tubing or hose designed to operate at high pressure (up to 15000 psi).
[0091] In a preferred embodiment, the duct 14 may be a high-pressure rubber and/or stainless steel hose, while the duct 16 may be a hose of polymeric materials for extreme pressure with 2-inches rubber or neoprene cover, or 2-inches high-pressure 1502 carbon steel pipe.
[0092] The duct 22 which is interconnected to the outlet duct 16 to supply the superheated steam to the oil facility to be subjected to a cleaning and/or stimulation process may be a flexible hose which in a preferred embodiment is a metal hose with rubber coating, designed to withstand up to 5,000 psi, of a dimension appropriate to the volumetric rate to be supplied, preferably 2 inches.
[0093] The connection type used to interconnect the system for generating superheated steam with the oil facility to be subjected to the cleaning and/or stimulation procedure are fast connections to allow a fast, easy, practical, and safe interconnection.
[0094] Once all the elements have been interconnected and the system for generating superheated steam using hydrogen peroxide has been put into operation, the operating, pressure and/or rate conditions of each element are verified before the injection inside the well is made; once the intervention is performed, the characteristic parameters of each element are re-measured and a constant monitoring of the operating conditions is performed, once it occur a significant decrease in the efficiency of the system that impacts on production volumes, the injection is performed again and cyclically repeated to maintain optimum operating ranges.
[0095] In the reaction chamber of the steam generating reaction container 15, the exothermic reactions which generate the gaseous effluents are carried out (superheated steam) required for the cleaning and/or stimulation preferably of oil installations.
[0096] In a preferred embodiment, three reactants are mainly used in the reaction chamber: [0097] Hydrogen peroxide (H.sub.2O.sub.2) between 30% and 70% by weight; [0098] Potassium permanganate (KMnO.sub.4) as catalyst precursor; and, [0099] Sucrose (C.sub.12H.sub.22O.sub.11) known as common sugar, as organic fuel.
[0100] Hydrogen peroxide, at high concentrations, is a very corrosive substance, that when contacted with organic fuels can initiate a heat generating chemical reaction (exothermic reaction).
[0101] It has unexpectedly and surprisingly been found that hydrogen peroxide, once reacted with potassium permanganate to form manganese dioxide, which in turn functions as a reaction catalyst, if contacted with an organic fuel, such as sucrose or common sugar, reacts violently generating steam and pure oxygen at elevated temperature, which can reach up to 400° C. depending on the conditions and quantities of reactants used.
[0102] Potassium permanganate is a dark purple solid reactant, which has the property of oxidizing and decomposing the hydrogen peroxide when small amounts of this reactant are used.
[0103] In the chemical industry, potassium permanganate is considered a very strong oxidant, so that from the chemical reaction with hydrogen peroxide are obtained (in addition to heat for being an exothermic reaction), as reaction products the following: steam, oxygen, magnesium dioxide residues and traces of potassium hydroxide.
[0104] Considering the foregoing, the inventors of the present invention unexpectedly found from experimental work in the laboratory and pilot plant that the addition of organic fuels, such as sucrose (common sugar), yields reaction temperatures greater than those of prior art.
[0105] The chemical reactions that occur when the sucrose is incorporated in the reaction are fundamentally the following:
2KMnO.sub.4(s)+3H.sub.2O.sub.2(ac).fwdarw.2KOH.sub.(s)+2MnO.sub.2(s)+2H.sub.2O.sub.(g)+30.sub.2(g) (I)
16KMnO.sub.4(s)+C.sub.12H.sub.22O.sub.11(s).fwdarw.8K.sub.2CO.sub.3(s)+MnO.sub.2(s)+4CO.sub.2(g)+11H.sub.2O.sub.(g) (II)
##STR00001##
[0106] As will be appreciated, the chemical reaction occurring in the system for generating superheated steam using hydrogen peroxide of the present invention, consists essentially of reacting hydrogen peroxide with granulated potassium permanganate in the presence of a combustible substance, preferably sucrose: The required amounts of each compound are calculated stoichiometrically and depending on the application that will be given to the system.
[0107] Initially, the reaction mixture is prepared from the solid reactants of potassium permanganate (KMnO.sub.4) and sucrose (C.sub.12H.sub.22O.sub.11), using water as the solvent to form the solid blocks which are to be introduced into the reaction container and subsequently reacted with the hydrogen peroxide and generate the catalysts. Once the reaction has started, the blocks go from a solid state to a liquid state (aqueous).
[0108] As can be seen from the reaction scheme, hydrogen peroxide (H.sub.2O.sub.2(ac)) reacts with potassium permanganate (KMnO.sub.4) to produce carbon dioxide (MnO.sub.2), which in turn functions as a catalyst in the reaction (III) wherein the combustible substance reacts with the released oxygen causing a violent reaction generating mainly steam at a very high temperature. This is because the combustible substance can generate an exothermic reaction when combined with the released oxygen, produced from the decomposition reaction of the peroxide in the presence of MnO.sub.2. The released oxygen is considered atomic rather than molecular, since it is first separated from the hydrogen peroxide. Therefore, oxygen is even more susceptible to combination with the combustible substance.
[0109] The different catalysts used for the catalytic decomposition of hydrogen peroxide are the following: manganese oxide IV or manganese dioxide (MnO.sub.2), iron oxide III (Fe.sub.2O.sub.3), calcium oxide (CaO), lead oxide (PbO.sub.2), calcium oxide (Ca(OH).sub.2). Other catalysts used are aluminum oxide (Al.sub.2O.sub.3), copper oxide II (CuO), copper oxide III (Cu.sub.2O), potassium chromate (K.sub.2CrO.sub.4), potassium dichromate (K.sub.2Cr.sub.2O.sub.7), the transition metal compounds also used for peroxide decomposition are the following: K.sub.2CrO.sub.4, KMnO.sub.4, CuSO.sub.4, among others.
[0110] It is important to note that the formed potassium hydroxide (KOH) is an inorganic salt whose dissolution in water generates heat (strongly exothermic reaction), so that a strong reaction can occur when the potassium hydroxide is added to the water, helping therefore to increase the temperature in the system.
[0111] The KOH is a salt and its ions are dissociated in water in the following form:
H.sub.2O+KOH.fwdarw.K+, OH—, H.sub.2
[0112] In the system for generating superheated steam of the present invention, an aqueous solution of hydrogen peroxide is used between 30% and 70% by weight. The water present in this solution does not participate in the reactions; however, it absorbs the energy produced from these reactions by changing from liquid state to steam.
[0113] It can be seen in reaction (II) that a part of the sucrose (C.sub.12H.sub.22O.sub.11) reacts with the potassium permanganate (KMnO.sub.4) producing manganese dioxide (MnO.sub.2), carbon dioxide (CO.sub.2) and steam.
[0114] The three reactions together produce the following gaseous effluents: CO.sub.2, O.sub.2 and H.sub.2O; so, once the sucrose (C.sub.12H.sub.22O.sub.11) and the potassium permanganate (KMnO.sub.4) have been consumed the only reaction that occurs in the reaction chamber is only and exclusively the hydrogen peroxide decomposition in the presence of the catalyst, manganese dioxide (MnO.sub.2) that is to say:
##STR00002##
[0115] In this decomposition reaction (IV) influences factors such as pressure, temperature, and reactant concentration, but also must consider the presence or not of a catalyst, which, as already mentioned for this reaction, the manganese dioxide (MnO.sub.2) performs this function.
[0116] Manganese dioxide (MnO.sub.2), is a mineral that under normal conditions is gray metallic. It usually is formed by the manganese deposition in sediments or by the oxidation of other manganese and iron minerals, such as quartz or limonite.
[0117] This decomposition reaction theoretically produces a steam mass composition of about 76.5% by weight and oxygen of 23.5% by weight.
[0118] The decomposition of the hydrogen peroxide by itself does not create the desired temperatures. A 50% aqueous solution of hydrogen peroxide in contact with the permanganate will raise the temperature in the reaction tank. However, with the addition of the combustible substance from organic origin, preferably sucrose, unexpectedly it has been found the conditions given in Table 1.
[0119] The operation of the temperature scale (from 80° C. to 400° C.) will depend on the design that is made for the intervention based on the characteristics of the same, therefore the variable operating temperature (operating window) will depend on the concentration of the hydrogen peroxide solution to be used in conjunction with the catalysts and the back pressures to which the reaction container is subjected.
[0120] On the other hand, as organic fuels can also be used gasoline and/or coal dust, among other common fuels.
[0121] In Table I, the conditions achievable with the system of the present invention are shown:
TABLE-US-00001 TABLE 1 Parameter Minimum Maximum Observations Temperature 80 180 Peroxide from 30 to 50% (° C.) concentration Temperature 80 400 Peroxide from 50 to 70% (° C.) concentration Pressure 0 3000 Pressure regulated by (psi) injection valve Notes The back pressures to which the system is subjected, either by manual throttling to accelerate the effluent speed (vapor) or automatic to counter the external back pressures, or for solid buffers present in the facilities to be treated (wells and/or surface installations); act directly on the working pressure generated by the reactor. The temperature (scale between 80° C. and 400° C.) will depend on the concentration of hydrogen peroxide used, according to the intervention design that is generated for each installation to be treated, depending on the maximum and minimum temperature conditions that its components support, mainly the elastomers present in pumps.
[0122] To overcome the drawbacks of the prior art, a system for generating superheated steam has been designed, using hydrogen peroxide and a set of reactants which produce an exothermic reaction. It is very important to mention that during the reaction, catalysts are generated that decompose hydrogen peroxide into superheated steam at temperatures ranging from 80° C. (17° F.) to 400° C. (752° F.).
[0123] Depending on the conditions with which it is required to operate, the reaction allows to obtain a vapor with a higher injection temperature (superheated steam) and a better quality in the steam (100% without water drops in suspension) than any other known system in the prior art, with a negligible oxygen concentration.
[0124] The steam obtained with the present invention is used for the injection into oil fields or for cleaning petroleum installations such as pipelines, heads, discharge lines, separation batteries, coolers, production wells, heat exchangers, tanks, refineries, coke treatments, fluid mobility, etc.
[0125] It should be noted that only superheated steam is injected, because the system of the present invention is designed to in no way inject hydrogen peroxide into the well and/or pipe, to avoid that could affect the chemical nature of the crude, as well as the nature of the equipment and/or facilities, since a balanced reaction is carried out inside the reactor thus obtaining a conversion of 100% hydrogen peroxide into superheated steam. Within the reaction chamber of the reactor, the reactant quantities, the hydrogen peroxide flow, and the design thereof have been optimized to ensure the highest efficiency in reaction with the sole aim of avoiding, at its maximum expression, gaseous effluents containing reactants. In addition, it is important to note that the temperature within the reaction chamber of the reactor, allows the self-accelerated decomposition of the hydrogen peroxide.
[0126] The system of the present invention is fully portable and of instantaneous steam generation, which allows to move the system to any remote installation, besides not requiring special adaptations for its interconnection, nor water is required for the steam generation, nor ignition gas to generate steam. The latter is one of the major advantages of the present invention in safety aspects, since the oil installations are operated without explosion risk, since no fire is required for the heating.
[0127] Even more prominent is the fact that by applying the system for generating superheated steam of the present invention, no expense is required to adapt the wells and/or facilities, thus providing a practical, economic, and functional system, which has advantages over any other prior art system.
[0128] Once the stimulation procedure has been applied with the system of the present invention, the production increasing effects in the well are immediately visible upon completion of the procedure, and may even be visible while the steam injection is performed (from 1 to 2 hours), reaching its production peak approximately in one month, stabilizing and obtaining its reorder point, being able to maintain it with 1 to 2 monthly cycles until exhausting the reserves.
[0129] The process consists of three main phases: injection, soaking and production. The injection phase basically consists in injecting a certain amount of 100% quality superheated steam into the reservoir at a predetermined pressure and temperature rate, for one or several hours, depending on the characteristics of the producing formation and the well conditions.
[0130] At the end of the injection, the well is closed for 1 day soaking period to allow the steam to warm and permeate the producing formation (reservoir) and spread evenly around the well. Subsequently it opens to production until the production curve falls and the intervention is required again, period that has on average 2 interventions per month.
[0131] A well can undergo several injection cycles, minimum 2 every 15 days, which will depend on the mechanical conditions of the well and the production. The increase rate of production at 24 hours, which has been observed with this system, has been superior to 30% in wells of high productivity, as well as increases in low productivity formations of more than 100%, these increases depend on own factors of the formation, crude type, recovery system type, °API of the oil, among other technical characteristics present in the wells to be treated. Additionally, the technology of this invention is applicable to any type of reservoir geology, continuous and discontinuous sands, limestones, naturally fractured limestones, etc.; so, there is no need for complex studies or numerical simulation of reservoirs for their application.
[0132] In the case of surface installation cleaning, the results are immediate once the treatment with superheated steam is finished, further reducing the operating costs minimizing the stop times of the installations, as for example the cleaning of a heat exchanger in a refinery.
[0133] The cyclic superheated steam injection using the system of the present invention is an improved recovery method consisting of injecting superheated steam into the reservoir for a short period; once the steam is injected, the well is closed so that the steam transfers its heat energy to the reservoir; and finally, the well is open to production. The cycle is repeated until the well is no longer profitable.
[0134] The steam injection allows reducing the viscosity of the oil inside the reservoir to improve the mobility of the same and to allow its displacement towards the production system, as well as to remove the paraffins, asphaltenes and solids present, that generate blockages in the systems.
[0135] The present system for generating superheated steam using hydrogen peroxide, in addition to the reservoir stimulation, can also be used for cleaning the rigging used during mechanical pumping, thus improving the operating conditions of the mechanical pumping system and improving the supply of fluid from the well, by cleaning the face of the producer intervals (downhole system where the oil enters to go up the surface), these small slots lose effectiveness when they are covered and therefore avoid the oil output, greatly reducing well production.
[0136] Also, with the intervention of the system of the present invention, the natural ability of the well to produce oil is restored.
[0137] It is very important to mention that conventional steam does not work in horizontal wells for its “hot water in the bottom” condition; however, the superheated steam system of the present invention operates horizontally, since it never loses its gaseous phase condition, allowing the intervention of wells in which horizontal fractures and multi-fractures have been carried out, as well as in wells of the new techniques of “fracking”.
[0138] The application of the system for generating superheated steam using hydrogen peroxide, compared to conventional methods in the application of the “Huff and Puff” methodology of steam injection, has no comparison in time, efficiency, and cost, in addition to the conventional technology for cleaning production wells, requires thermal wells for the lengthy injection for at least 28 days.
TABLE-US-00002 Characteristic Conventional boiler Superheated steam Injection Time 28 to 40 continuous 30 minutes to 3 days hours Closing time 30 days 1 day Incremental 6 to 7 months 3 weeks to 3 months production time Special thermal Is required Not required wells Use of fossil fuel Is required Not required Use of treated Is required Not required water Special connections Is required Not required and thermal insulation
Application Principle
[0139] The removal of solids in oil wells with superheated steam is given under the principle of heat transfer, by increasing the temperature of the hydrocarbon components they reduce their viscosity, increasing their mobility, and are removed, releasing the obstructed space, and allowing the free passage of fluids. On the other hand, in the stimulation of reservoirs, the same principle is considered, since when obtaining a temperature increase, not only the damage is removed near the well, but also the viscosity of the oil is reduced, allowing greater fluid supply from the formation to the well, thus increasing the production of hydrocarbons and making any oil project more profitable.
[0140] Carrying out the cleaning and/or stimulation, it is guaranteed the flow certainty in the integral production system obtaining a greater profitability. Also, the application of thermal technology helps significantly to solve the problems of formation damages, of interfacial phenomena type, such as: emulsion blockage that occurs when a viscous emulsion occupies the pore space near the well blocking the flow, decreasing the productivity rate, or alteration of the wettability or permeability, which occurs when the precipitation of asphaltenes in the porous media, alters the permeability of the formation, the rock is wetted by the petroleum, reducing the relative permeability of this, which hinders its movement in the porous media.
[0141] The temperature increase is the most efficient method for the cleaning and removal of heavy hydrocarbon components, by reducing the viscosity of the oil, which allows its movement through the production rigging.
[0142] The versatility of the system for generating superheated steam using hydrogen peroxide allows a higher injection temperature and a better quality of the obtained steam than any other known system of prior art, which allows to reach a greater depth, obtain temperature differentials greater than those existing in the well and consequently a greater effectiveness in the rigging cleaning.
[0143] Other advantages of the use of superheated steam from hydrogen peroxide is that steam is generated without water droplets in suspension, no emission of greenhouse gases is generated from the burning of fossil fuels, no waste contaminants is generated, no fire hazards, the crude is not contaminated, nor the pipes are corroded.
[0144] On the other hand, when the system of the present invention is used for the rigging cleaning, the main parameter to be evaluated is the comparison of the expected operating conditions, current operating conditions, operating conditions during the test, and final operating conditions; however, the most representative parameter to be measured that indicates if the rig and well cleaning are effective, is the percentage of effort in the rods.
[0145] The procedure for rigging cleaning is as follows:
[0146] a) Consider the design of the mechanical pumping rigging: [0147] Mechanical condition and production history. [0148] Operation of the well in ideal conditions. [0149] Potential to increase production. [0150] Volumetry of the steam to be injected. [0151] Obstructions along the rigging. [0152] Where the steam injection will be made (TP production pipe or TR casing).
[0153] b) Analysis of historical dynamometric charts.
[0154] c) Analysis of dynamometric charts prior to the intervention.
[0155] d) Analysis of dynamometric charts during the intervention.
[0156] e) Analysis of dynamometric charts after the intervention.
[0157] f) Optimization of mechanical pumping.
[0158] These considerations result in a document called Design Bases, which specifies all the requirements that can be considered for the operation; in the case of wells with obstruction of paraffin in the production pipe (TP) are considered three modalities of intervention:
[0159] a) direct injection by TP.—This case is considered when a partial obstruction of the TP has been identified, as operating margin is considered in the case of having resistance in the pumping, re-pressuring the TP with superheated steam injection up to 500 psi.
[0160] b) Injection by casing (TR).—This case is considered when a total obstruction has been identified in the TP, the operation consists of injecting superheated steam through the TR until re-pressuring the same to 500 psi, closing the well and giving waiting time of approximately 2 hours for the heat to be transmitted to the PT by removing the obstruction by means of the heating of the solids housed in the TP.
[0161] c) Steam injection into wells without production pipe by connection on the side.
[0162] The fundamental aspects to be evaluated are the correct operation of the mechanical pumping system and the benefit in production increments that can be obtained when using the system of the present invention.
[0163] The application of the system of the present invention, has as purpose to guarantee the flow certainty through the integral production system, removing obstructions, optimizing facilities, and guaranteeing the correct operation of the different types of production rigging.
[0164] It is important to mention that the system of the present invention employs an innovative technology for the superheated steam generation using hydrogen peroxide, so that the heat transmission in a homogeneous steam flow (superheated steam), allows remove reservoirs of paraffins, asphaltenes, heavy oil and solids, reservoirs that obstruct the fluid flow, causing a malfunction of the production rigging, or even render some integral production system components inoperable.
[0165] The operation principle is based on the thermal energy transmission at very high temperature (superheated steam) and with a 100% quality of steam, which when in contact with the reservoirs of heavy components of crude, reduces its viscosity and makes them highly fluid, so they are removed and allow the free passage of fluids and the correct functioning of the integral production system components.
[0166] The system of the present invention may be employed for:
[0167] 1. Well stimulation.—By means of the thermal energy transmission in the porous medium, the fluid flow in the reservoir increases, obtaining very significant improvements in well productivity and oil recovery, improving profitability and lengthening the life of the reservoirs, significantly increasing oil production.
[0168] 2. Cleaning of the vicinity of the well and face of the intervals.—The greatest impact or damage by drilling fluids and fracture fluids occurs in the area surrounding the well known as the “vicinity of the well”. In this area is the biggest change in the flow conditions in the reservoir, so it is also the area where changing the pressure and temperature conditions, the oil tends to precipitate paraffins and asphaltenes which obstruct the entry of fluids into the well. With the system of the present invention, carrying out the superheated steam injection it is transmitted thermal energy, which removes the damage near the well and the producing interval, eliminating the obstruction by paraffins and asphaltenes; in this way cleaned flow channels are obtained that allow the contribution of fluids to the well and consequently a greater uptake of production.
[0169] 3. Cleaning of rigging.—In the case of mature fields handling heavy oils or low productivity, the use of artificial production systems is essential. Due to the production fluid conditions, mechanical conditions of the system, the presence of heavy components derived from the oil and/or in combination with solids from the fractured formation, obstructions are formed, which do not allow the proper functioning of the artificial system or they leave it inoperative. By means of superheated steam circulations with the system of the present invention, all solids causing the above-mentioned problem are removed, leaving the rigging in optimum operating conditions, offering the benefit of not only cleaning the system components, but also all the pipes of the well and the face of the intervals.
[0170] 4. Discharge lines and transport ducts cleaning. —Along the production pipes and the transport pipelines, there are various conditions for the layout of the line, such as reduction or enlargement of diameters, changes of trajectory and/or bathymetry; as well as exposure to environmental temperatures, which influence the shear stresses and temperature changes during the layout, conditions favoring the precipitation of paraffins and asphaltenes. On the other hand, by the same characteristics of the production fluid, when exposed to conditions below its bubble point, large amounts of gas are lost, so that the fluid is modified in its behavior, reducing the viscosity, and generating high backpressures in the complete integral production system. With cleaning by the system of the present invention the obstructions are removed, leaving available the total flow area of the pipe for the free passage of the production fluids, thus reducing the system backpressures. When there is the presence of extra-heavy oils of very low viscosity, points of continuous injection can be determined along the duct, thus guaranteeing a reduction in viscosity throughout its trajectory, which makes it an integral system of flow certainty.
[0171] 5. Facility Cleaning.—The various production riggings are also susceptible to malfunction or disabling due to the presence of heavy, paraffin and solids. With the system of the present invention, when using superheated steam, it is possible to carry out the cleaning of equipment and accessories, without having to disassemble them or subject them to major maintenance involving their removal or disassembly.
[0172] However, the system operating philosophy of the present invention considerer strictly complying with environmental safety and protection standards at national and international level, so that the highest environmental safety and protection standards are always fulfilled.
[0173] The process for the operation and application of the system of the present invention in well is as follows:
[0174] 1).—Verification of facilities in field (site visit and determination of access route).
[0175] 2).—Preparations prior to the intervention (check supplies, tools, safety equipment and signage necessary to perform the intervention, conditions, and equipment functionality).
[0176] 3).—Transfer of equipment to the site of the intervention.
[0177] 4).—Location of equipment and verification of installation conditions.
[0178] 5).—Meeting with the staff to establish the work program and review the safety plan of the facility (emergency response plan).
[0179] 6).—Equipment installation (See
[0180] 7).—Meeting of Start of Operation to assign responsibilities and detail the steps to follow.
[0181] 8).—Preheating of the system.
[0182] 9).—Cleaning of the rigging: [0183] a).—The injection is made by the production pipe (TP) or by the casing (TR) as the case may be, until the pressure determined in the previous design of the intervention is reached, once said pressure is reached, it is closes the well and a settling time of approximately 2 hours is given, the pressure in TP is monitored and the opening of the well is carried out verifying the outlet of fluids. [0184] b).—The rigging cleaning is performed by opening the TR valve for the superheated steam injection, the TP valve is kept open and the TP pressure is monitored at the outlet until the return of fluid with steam is observed. Once this condition is reached, the well can circulate for a period of 5 min to ensure the removal of any heavy components from the rigging.
[0185] 10).—Well induction: [0186] a).—Once the well pressure is depressed, the stimulation treatment thereof is carried out, by injecting superheated steam with the system of the present invention according to the design conditions. The well is closed by giving time to soak and its production contribution is evaluated. [0187] b).—The outlet valve is closed in TP and the superheated steam injection is started to the formation. The injection time will depend on the analyzed and proposed well conditions. Once the scheduled injection time is reached, the injection valve is closed in TR and the steam pumping is stopped, closing the valves of the head.
[0188] 11).—Disconnection of equipment.
[0189] 12).—Removal of equipment.
[0190] 13).—Well opening.—Once the soak time has elapsed (1 hr. for cleaning and up to 48 hrs. for stimulation), the well is opened and aligns to the production rigging. The results are evaluated verifying the well contribution and operation conditions of the artificial system.
[0191] 14).—Monitoring and tracing.—The well production is evaluated on a constant basis, with level monitoring in the tank, establishing a limit to perform the treatment again. Once the production declines to a predetermined point, the treatment to restore production is performed again.
[0192] Also, the system for generating superheated steam using hydrogen peroxide can be used for the cleaning of discharge lines, oil-gas-ducts, and connections to the collection head. The parameters to be evaluated during the operation, is the back pressure that exists in the discharge line, for which the pressures in the well head and in the connection to the head are measured to determine the pressure differential in the line. Once the cleaning is performed, the pressure differential is remeasured, whereby the effectiveness of the treatment is determined using the steam generation system of the present invention. When cleaning, a waste tank or metal dam is used to contain debris from the pipes because of cleaning, and in this way, it is also possible to determine if there is presence of solids on the discharge line that obstruct the free passage of fluids towards the collection head.
[0193] The process for cleaning the discharge lines by the present system for generating superheated steam using hydrogen peroxide is as follows:
[0194] 1).—Transfer of the equipment to the site of the intervention.
[0195] 2).—Location of the equipment and verification of the installation conditions.
[0196] 3.—Meeting with the staff to establish the work program and review the facility security plan (emergency response plan).
[0197] 4).—Equipment Installation: [0198] a).—Connection of the output of the steam generator to the standpipe of the discharge line. [0199] b).—Connection of the discharge line to the metal dam.
[0200] 5).—Components verification and installation.
[0201] 6).—Meeting of start of the operation to confirm assignment of responsibilities and detail the steps to follow.
[0202] 7).—Preheating of the steam generation system (equipment startup).
[0203] 8).—Once the pressure, temperature, and vapor saturation conditions have been reached, the injection is started for the cleaning of the line according to the previously calculated volumes for the treatment.
[0204] 9).—The color characteristics are verified at the exit of the metal dam.
[0205] 10).—The superheated steam supply is closed and the discharge line is reconnected to the head.
[0206] 11).—It is verified that the lines are depressurized and disconnection of the equipment is made.
[0207] 12).—The equipment is disassembled in its entirety and the order and cleaning of the area is verified.
[0208] 13).—The results are evaluated and it is determined if there are improvements in the flow conditions, as well as reduction of the pressure differential at the inlet and outlet of the line.
[0209] The system for generating superheated steam using hydrogen peroxide of the present invention can also be used for the thermal cleaning of measurement ducts in the installation and general production ducts of the same installation. The parameter to be evaluated is the back pressure that exists in the discharge line, so the pressures in the well head and in the connection to the head are measured, to determine the pressure differential in the line. Once the cleaning was made, the pressure differential is remeasured to determine the effectiveness of the treatment.
[0210] When cleaning a waste tank or metal dam, it is also possible to determine if there is presence of solids in the discharge line, which obstruct the free passage of fluids to the collection head.
[0211] The procedure, to carry out the thermal cleaning of the measuring ducts and the general production ducts in the installation is as follows:
[0212] 1).—Transfer of the equipment to the intervention site.
[0213] 2).—Location of the equipment and verification of the installation conditions.
[0214] 3) Meeting with the staff to establish the work program and review the facility security plan (emergency response plan).
[0215] 4).—Equipment Installation. Interconnection of the steam generation system to the duct.
[0216] 5).—Components verification and installation (check list).
[0217] 6).—Meeting of start of the operation to confirm assignment of responsibilities and detail the steps to follow.
[0218] 7).—Preheating the steam generation system (equipment start).
[0219] 8).—Once the pressure, temperature and vapor saturation conditions have been reached, the injection is started for the cleaning of the line according to the calculated volumes for the treatment
[0220] 7).—Preheating of the steam generation system (equipment startup).
[0221] 8).—Once the pressure, temperature, and vapor saturation conditions have been reached, the injection is started for the cleaning of the line according to the calculated volumes for the treatment.
[0222] 9).—The locking valves of the ducts are closed.
[0223] 10).—The superheated steam supply is closed.
[0224] 11).—It is verified that the lines are depressurized and disconnection of the equipment is made.
[0225] 12).—The equipment is disassembled in its entirety and the order and cleaning of the area is verified.
[0226] 13).—The results are evaluated and it is determined if there are improvements in the flow conditions, as well as reduction of the pressure differential at the inlet and outlet of the line.
[0227] However, when the system for generating superheated steam using hydrogen peroxide is used for the stimulation of offshore oil reservoirs, the procedure is as follows:
[0228] 1).—Well measurement before treatment.
[0229] 2).—Introduce the system for generating superheated steam directly in the well bed in the form of chambers, which will have the characteristics suitable to conform to the pipe and bottom conditions, so that the reaction is generated directly at the bottom hole, or else the injection can be effected from the surface using flexible tubing.
[0230] 3).—Depending on the well characteristics, to place in series or not several interconnected equipment, to generate the chain reaction, thus avoiding both the loss of pressure and counteract the thermal shock.
[0231] 4).—Close the well to give time to soak and that the heat transfer is carry out.
[0232] 5).—Open the well and monitoring production.
[0233] 6).—Once the production with the stimulation starting is reached again, repeat the treatment.
[0234] Prior to start-up, must be carried out the following:
[0235] 1).—Verification of facilities in the field (visit to the site and determination of access route).
[0236] 2).—Preparations before intervention (verification of valve shafts, connections type to be used, safety measures, connection of containment systems).—.
[0237] 3).—Conditioning of the access route.
[0238] 4).—In the case of rigging cleaning, it is required open the wells by the casing at least 5 days before the intervention to not have gas repression for the steam injection.
[0239] 5).—Verification of access path one day before the intervention to prevent setbacks.
[0240] The intervention consists of:
[0241] 1).—Preparations before intervention (verification of supplies, tools, safety equipment and signage necessary to perform the intervention, conditions, and equipment functionality).
[0242] 2).—Transfer of equipment to the site of the intervention.
[0243] 3).—Location of the equipment and verification of the installation conditions.
[0244] 4).—Meeting with the staff to establish the work program and review the facility security plan (emergency response plan).
[0245] 5).—Photographic evidence is taken of the state of the location, valve shaft, counter-well and equipment, to make the corresponding report.
[0246] 6).—Equipment Installation.—The required equipment is accommodated, the unit employing the system for generating superheated steam of the present invention is located, 2 meters from the head in front of the well.
[0247] 7).—The interconnection of the system for generating superheated steam is carried out with the well installations (reservoir) to be stimulated, as well as the metallic dam.
[0248] 8).—Meeting of start of the operation to confirm assignment of responsibilities and detail the steps to follow.
[0249] 9).—It is verified that all the valves of the system for generating superheated steam are closed.
[0250] 10).—The hydrogen peroxide supply to the pump is opened.
[0251] 11).—The venting of the reaction chamber to the atmosphere is opened.
[0252] 12).—The hydrogen peroxide pumping to the reaction chamber of the present system is initiated.
[0253] 13).—The temperature and steam quality at the reaction chamber outlet are verified.
[0254] 14).—Once the desired temperature is reached, the injection to the well begins.
[0255] 15).—The pressure is regulated by partially closing the venting, once the desired pressure has been reached, the partial or total closing of venting is maintained.
[0256] 16).—The pump operation is maintained until the hydrogen peroxide flow is stabilized.
[0257] 17).—Once the calculated theoretical volume of hydrogen peroxide has been pumped, the pumping stops (pomp stop).
[0258] 18).—The interconnection of the of system for generating superheated steam with the well installations (reservoir) to be stimulated is closed.
[0259] 19).—The peroxide supply to the pump is closed.
[0260] 20).—Any pressure in the system is relieved to generate superheated steam, fully opening the venting.
[0261] 21).—The disconnection of the system for generating superheated steam with the well installations (reservoir) to be stimulated is carried out.
[0262] 22).—The disconnection of the line to the metal dam is made.
[0263] 23).—The interconnection of the standpipe to the production pipe is made.
[0264] 24).—Equipment is secured and disassembled.
Examples of Application
[0265] The following are three application examples of the system for generating superheated steam using hydrogen peroxide of the present invention, where in the first two was made the cleaning of mechanic pumping riggings and in the third example was carried out a stimulation process.
Well 1
Application Principle
[0266] The elimination of solids in oil wells using superheated steam is given under the principle of heat transfer. As the temperature of the hydrocarbon compounds increases, they reduce their viscosity and increase their mobility, so they are removed releasing the clogged space and allowing the free passage of fluids. On the other hand, in the stimulation of reservoirs, the same principle of increase in the temperature of the hydrocarbons generated by superheated steam is considered, allowing not only the removal of the damage near the well, but also the reduction of viscosity of the oil allowing greater contribution of fluid from the formation to the well, thus increasing the hydrocarbons production and making more profitable any oil project.
[0267] When performing the cleaning and/or stimulation of the well, it is guaranteed the flow assurance in the integral production system, obtaining a greater profitability in any petroleum project.
Objective
[0268] Derived from the high presence of paraffin found in Well 1, it was proposed to perform the cleaning of the pneumatic pumping rigging, using the steam injection in the rigging, which steam was obtained by the system for generating superheated steam using hydrogen peroxide of the present invention, thereby the operating conditions of the artificial pneumatic pumping system and the supply of fluid from the well was improved.
Background
[0269] In
Evaluation Criteria
[0270] For the cleaning of the rigging, the following evaluation points were defined:
[0271] 1. EQUIPMENT EFFICIENCY: Considering transport, installation, versatility, operating time.
[0272] 2. OPERATION OF PNEUMATIC PUMPING RIGGING: The correct opening and closing of each and every one of the valves of the rigging is considered.
[0273] 3. PRODUCTION EVALUATION: The comparison between the measurement before operation and the after the same is considered.
[0274] 4. OBSERVATION OF FLUID RETURN TO METALLIC DAM: Samples of the returned fluids are taken, as well as measurement of the same.
Development of Activities
[0275] The activities performed are shown.
Hour Operation
[0276] 10:30-11:30 Arrival of operative staff. The permission to work in the well is filled. [0277] 11:30-1:30 System connections to the casing (TR) are made and from the metal dam to production pipe outlet(TP) based on the recommendations of the facility security personnel. Lines are tested, no leakage is detected in lines and valves of vent to dam. [0278] 14:00-14:45 It starts with the ignition of the steam generation system, with initial pressure in TP of 7 kg/cm.sup.2. Steam is injected through the annular space at 150 psi pressure and an average temperature of 110° C. The injection is performed for 45 min, detecting a pressure increase in the system up to 300 psi. The injection of vapor is cut to initiate the heat exchange towards the rigging. [0279] 14:00-15:15 Time is given for the heat exchange for the cleaning of the rigging. [0280] 15:15-16:30 The well was operated with pneumatic pumping aligned to the dam, recovering 3 m.sup.3 of paraffin [0281] 16:30-17:00 The paraffin is recovered from the metal dam, by a tank truck sent by the operations personnel. The disconnection of the equipment is performed, the location is verified applying order and cleaning. The equipment is removed.
Results
Equipment Efficiency—Successful
[0282] a. The transportation was carried out without any 5 inconvenience due to the physical characteristics and design of the equipment
[0283] b. As for the installation, it was done in a time of 2.5 hours. Here, an opportunity area was found that could be improved using high pressure flexible hoses and high temperature for the connections at floor level.
[0284] c. The equipment operating time was 45 min, injecting a volume of 35 m.sup.3 at well conditions, at average pressure of 150 psi and an average temperature of 230° F. (110° C.).
[0285] d. Return of paraffins was observed in metal dam and samples were taken.
Operation of Pneumatic Pumping Rigging—Successful:
[0286] e. Regard to operation of the rigging BN post-operation, the staff in charge of the well operated the rigging checking the correct opening and closing of the 7 pump-out valves, leaving the well operating with the orifice valve, providing production fluid.
Production Evaluation—Successful:
[0287] f. The measurement of the well after the intervention is shown:
[0288] The well showed a flow (Qo) of 119,760 barrels per day (BPD).
[0289]
Final Comments
[0290] Because of the cleaning of the production rigging with BN of the well, it was observed that the cleaning was successful in observing the return of paraffin housed in TP. [0291] When operating the BN, the correct opening and closing of all rigging valves was observed; staying operating with low pressure in the BN network of 30 kg/cm.sup.2 to 15 kg/cm.sup.2 observing oil supply aligned to battery. [0292] There is an increase of 36.71% in the daily well production. [0293] The use of flexible hoses for high pressure and high temperature is recommended to minimize leakage points, installation times and logistics.
[0294] The safety requirements requested by the operator to carry out the activity were fulfilled; Abiding at all times the observations made by the security personnel.
Well 2
Objective
[0295] Perform the thermal cleaning with the injection of superheated steam generated by hydrogen peroxide in well 2, improving the operation conditions of the artificial mechanical pumping system and improving the supply of fluid from the well. The behavior of the well 2 is shown in
Evaluation Criteria
[0296] For the accomplishment of this intervention, the following points for the evaluation were defined:
[0297] 1. EQUIPMENT EFFICIENCY: Considering transport, installation, versatility, operating time.
[0298] 2. EFFICIENCY OF MECHANICAL PUMPING RIGGING: The reduction of load in the UBM and the optimum operation of the system is considered.
[0299] 3. PRODUCTION EVALUATION: The comparison between the previous measurement to the operation and the subsequent is considered.
[0300] Development of Activities:
[0301] The activities performed are shown.
Hour Operation
[0302] 14:00-15:00 Aligned to metal dam, the well is vented from 100 psi in TR at 0 psi. [0303] 15:00-15:40 With the well aligned to the metallic dam, is effected the superheated steam injection by annular space with 250 psi of pressure and a temperature ranging from 230° F. (110° C.) to 284° F. (140° C.) in injection line and increase in temperature in the TP line (return) from 40 to 92° C., the injection is performed for 35 min. Where it is observed steam outlet along with oil to metal dam. Total volume of injected steam 175 m.sup.3 at surface conditions. [0304] 16:00-17:00 UBM is put into operation to evacuate fluids aligned to metal dam, observing return of oil and paraffins, samples are taken. Operative personnel align well to production, disconnection of the equipment is carried out, suction of fluids of metallic dam is made, the location applying order and cleaning is verified. Equipment from the location is removed.
Results
Equipment Efficiency—Successful:
[0305] a. The transportation was done without any inconvenience due to the physical characteristics and the equipment design.
[0306] b. As for the installation, was carried out in a time of 3 hrs. Here, an opportunity area was found that could be improved using high pressure and high temperature flexible hoses for the connections at floor level.
[0307] c. The operating time of the equipment was 35 min, injecting a volume of 52.5 m to well conditions, at average pressure of 150 psi and average temperature of 248 OF (120° C.).
[0308] d. Steam circulation was observed with paraffins return with production fluids in metallic dam without the need to operate the UBM.
Efficiency of Mechanical Pumping Rigging—Successful:
[0309] About the efficiency of the BM, it was verified with the dynamometric chart, Observing a great improvement in the efficiency of the mechanical pumping, better filling of the pump and increased production.
[0310]
Production Evaluation
[0311] The measurement of the well after the intervention is shown obtaining 36 barrels per day (BPD) of incremental production.
[0312]
Remarks and Comments
[0313] Because of cleaning of production rigging of BM of the well, the following is observed: [0314] Complete steam circulation was observed, according to program. [0315] Personnel of measurement company mentioned that qualitatively observed improvement in the operation of the UBM motor. [0316] Return of solids and paraffins was observed in both metallic dam and samples taken, confirming the removal of material housed inside the TP
[0317] An echocardiogram and dynamometric chart will be made for comparison of before and after treatment.
Well 3
Objective
[0318] To increase the production of the treated well, removing damages in the formation and improving the fluid mobility with the injection of superheated steam generated by hydrogen peroxide; also, improving the operating conditions of the artificial mechanic pumping system and improving the supply of fluid from the well.
Background
[0319] The Odessa-Midland area is in South Texas and contains reservoirs of sands interspersed with crude oil types that mostly range from heavy to extra heavy type, the fields have 90% secondary recovery systems being the mechanical pumping type the prevailing in the wells.
Scope
[0320] Increase production in oil wells by stimulation by means of superheated steam. [0321] Evaluate the technology impact on cleaning times and removal of solids in well components. [0322] Evaluate the technology scope in terms of intervention time, hydrogen peroxide rate and reactants. [0323] Validate the procedures and evaluation criteria of each intervention in oil wells. [0324] Verify the general operating conditions of oil wells in the area. [0325] Test the technology in progressive cavity wells.
Well Characteristics
Well 1:
[0326] Depth: 350 meters.
Arrangement: TR and TP.
[0327] Bottom pressure: 20 lbs.
Head pressure: 50 lbs.
Pump Type: Progressive Cavity.
[0328] Average Production: 1 barrel per day.
Well 2:
[0329] Depth: 600 meters.
Arrangement: TR and TP.
[0330] Bottom pressure: 25 lbs.
Head pressure: 100 lbs.
Pump Type: Mechanical Pump Mark II.
[0331] Average Production: 1.5 barrel per day
[0332] It was observed that in the well 1 had very low pressure, which indicates obstructions by precipitation of paraffins, the use of emulsion-breaking chemicals to control these precipitations was observed, the crude extracted from the well is extra heavy, is operating in the Well a progressive cavity pump by the density of the crude and the handling of solids that the well contains, it is important to emphasize that it is the first time that a steam system is applied in wells of these characteristics.
[0333] In well 2 were observed paraffin precipitations and the use of emulsion-breaking chemicals to control such precipitations, the well was operating with a mechanical pump Mark II, which only operates about 1 hour daily, heavy crude is observed, this well was subjected to a “fracking” process, increasing its production to 40 barrels per day the same that fell for one month to its current production of 1.5 barrels per day.
Intervention with Superheated Vapor System in Well 1 (Progressive Cavity)
[0334] The following operating parameters were determined: [0335] Intervention time: 30 minutes [0336] Maximum operating temperature: 140° C. [0337] Maximum operating pressure: 150 psi. [0338] Connection of the system by TR (casing) leaving TP open (production pipe) always.
[0339] Because the type of pump in this well has an elastomer that can be susceptible to damage by high temperatures, and considering that a thermal stimulation or cleaning medium has never been used in this type of pumps, it was proceed to intervene the well with additional supervision measures, monitoring at all times the behavior of the pump and leaving it to operate to avoid accumulation of pressure or temperature in the pump, at the end, the intervention time in the well was of 17 minutes with the following results: [0340] The steam injection was made by TR, the complete circulation of the well it took only 5 minutes observing superheated steam outlet of by TP. [0341] The paraffin output was observed once it was circulated in a well for 2 more minutes and then oil with a lower density.
Results:
[0342] The production of the well increased by 10 barrels per day, the pump never stopped operating.
Intervention with Superheated Steam System in Well 2 (Mechanical Pumping)
[0343] The following operating parameters were determined for well 2: [0344] Intervention time: 1 hour [0345] Maximum operating temperature: 180° C. [0346] Maximum operating pressure: 200 psi. [0347] Connection of the system for generating superheated steam by TR (casing) leaving TP (production pipe) open for 15 minutes to clean the production rigging and the remainder closing TP (production pipe) for the stimulation of the formation.
[0348] The intervention time was 1 hour with the following results: [0349] Injection of steam by TR it took in completely circulate the well, 7 minutes having steam outlet by TP. [0350] The paraffin output was observed once it was circulated in a well for 10 minutes more and then oil with a lower density. [0351] TP was closed after 17 minutes to give opportunity to vaporize the formation, pressure increases in the head and continuous circulation of steam each time the TP valve was opened for verification. [0352] Once completed the intervention, TP and TR were closed to give a soak time of 18 hours. [0353] The next day TR was opened and depressurized, TP was then opened and the pump was shaken as it contained gas, the pumping started with 100 pounds of pressure in the head and 200 pounds in the operation of the pump.
Results
[0354] Production of the well increased by 30 barrels per day. [0355] Production of crystalline water was observed in the well, as result of fracture water residues from a previous intervention.
[0356] While a preferred embodiment of the present invention has been described and shown in the foregoing description, it should be emphasized that numerous modifications are possible thereto, without departing from the true spirit of the invention, such as modifying the elements forming the present system, as well as their disposition and interrelation. Thus, the present invention should not be restricted except as required by the prior art and the appended claims.