Method for Forming a High-Performance Aqueous-Phase Polymer Fluid and System for Drilling Well Bores in Low-Gradient Formations

Abstract

The present invention relates to a method to form or obtain a high performance aqueous phase polymer fluid, which is a seawater-based drilling fluid for well drilling in low gradient formations. It is formulated based on liquid state polymer chemical products, easy to aggregate, and quickly mixed; a preparation and homogenization process that reduces preparation times, designed to drill hydrocarbon-producing deposits, focusing on minimizing damages to the producing formations, with a high rate of circulation loss in naturally fractured deposits. The system is environmentally-friendly, it complies with the main functions required of drilling fluids, while also providing a high inhibition control by swelling and dispersion of clay zones, due to the polymeric nature of the materials with which it is formulated. It is a fluid that does not contain solids in its formulation and provides an excellent transport and cleaning of drilling shears in the well.

Claims

1. Method to form a high performance aqueous-phase polymer fluid, comprising the following steps: a) Provide a dam or tank with stirring system; b) Provide a deep-well pump; c) Provide a diaphragm pump and suction and discharge hoses; d) Provide a clay stabilizing container; e) Provide a filtration reducer container; f) Provide a glycol Amine mixture inhibitor container; g) Add seawater using the deep-well pump to a selected channel or tank selected for the preparation, up to 80% of its capacity, and employ the stirring system of the dams or tanks; h) With the support of the diaphragm pump, the pumping of products of the high performance aqueous-phase polymer fluid formulation will be done to the dam or tank, first adding a viscosifier; i) Place the suction diaphragm pump in the clay stabilizer (Dispersion), and pump the product, continue with system stirring; j) Place the suction of the pump in a container of filtrate reducer; keep pumping and mixing system; k) By using the support of the diaphragm pinup, continue with the addition of corrosion inhibitor and mixing the system; l) Place the suction in the inhibitor mixture amine glycol and pump the clay inhibitor (Swelling), and continue mixing the system; and m) If the operation allows it, complete the 30-minute stirring time of the system after adding all the material.

2. The method to form the high performance aqueous-phase polymer fluid, as claimed in claim 1, characterized in that in step g) seawater is added in the ratio of 974.80-966.30 liters/m.sup.3.

3. The method to form the high performance aqueous-phase polymer fluid, as claimed in claim 1, characterized in that in step h) the viscosifier is added until a concentration of 8.10-10.80 liters/m.sup.3 is reached.

4. The method to form the high performance aqueous-phase polymer fluid, as claimed its claim 1, characterized in that in step i) clay stabilizer (Dispersion) is added until a concentration of 2.70-3.60 liters/m.sup.3 is reached.

5. The method to form the high performance aqueous-phase polymer fluid, as claimed in claim 1, characterized in that in step j) the filtering reducer is added until a concentration of 7.20-9.60 liters/m.sup.3 is reached.

6. The method to form the high performance aqueous-phase polymer fluid, as claimed in claim 1, characterized in that in step k) the corrosion inhibitor is added until a concentration of 1.80-2.50 liters/m.sup.3 is reached.

7. The method to firm the high performance aqueous-phase polymer fluid, as claimed in claim 1, characterized in that in step l) the Amine Glycol mixture inhibitor is added until a concentration of 5.40-7.20 liter/m.sup.3 is reached.

8. The method to form the high performance aqueous-phase polymer fluid, as claimed in claim 1, characterized in that the wear of the deep-well pump may be between 600-800 liters/m.sup.3.

9. The method to form the high performance aqueous-phase polymer fluid, as claimed in claim 1, characterized in that the diaphragm pump in step h) has a 3″ suction and discharge diameter with a 237 gal/min pump capacity, model PD30X-XXX-C, suction and discharge hoses with a diameter of 3″ and length of 15 meters', each reinforced with steel to manage pressure of 250 psi, with, fist connections in both ends, located in the suction and discharge pump.

10. The method to form the high performance aqueous-phase polymer fluid, as claimed in claim 1, characterized in that each preparation tank has 70 cm blade stirrers (4 blades total), with a torque of 50-70 rpm with 30 HP electric motor and which continually stir the preparation tanks for the high performance aqueous-phase polymer fluid positioned in their respective sites.

11. The method to form the high performance aqueous-phase polymer fluid, as claimed in claim 3, characterized in that after step m) the well is pumped by using a 6″×12″ triplex pump to carry out the drilling work.

12. A Drilling system using a high performance aqueous-phase polymer fluid, comprising: Mixing channels or tanks of 45 m.sup.3 minimum capacity; 45 HP centrifuge pumps; 3 kpascal air compressor; 2 pumps with a pumping capacity of 275 gpm (Diaphragm or Variable speed pump); suction and exhaust hoses resistant to chemical products and hydrocarbon byproducts; heavy-duty bronze quick connections; and air hoses with connections.

Description

DESCRIPTION OF THE INVENTION

Brief Description of Figures

[0022] FIG. 1 is a graph representing the reduction of volume loss.

[0023] FIG. 2 is a graph representing the reduction in drilling times of the Cantarell 3017 well.

[0024] FIG. 3 is a graph representing the reduction of logistics on volume of materials to generate 10,000 (pcs, racks/tote).

[0025] FIG. 4 is a graph representing the pre-treatment of seawater for drilling fluids preparation in hours.

[0026] FIG. 5 is a graph representing the generation times in hours, of 70 m.sup.3.

[0027] FIG. 6 is a graph representing the lubricity ratio: Standard NMX-L-167-SCFI-2004.

[0028] FIG. 7 is a condensed schematic chart of the method for the preparation of the high performance aqueous-phase polymer fluid.

[0029] FIG. 8 is a graph representing the percentage of linear swelling of the high performance aqueous-phase polymer fluid with formation shears of the Cantarell BTPKS field.

[0030] FIG. 9 is a graph representing the percentage of shear dispersion for Cantarell BTPKS flied formation.

[0031] FIG. 10 is an example which illustrates the appearance of the high performance aqueous-phase polymer fluid dispersion obtained through the method of the present invention and the drilling shear pill, Mix 3.

[0032] FIG. 11 is an example which illustrates the appearance of the high performance aqueous-phase polymer fluid dispersion obtained through the method of the present invention and the perforation shearing pill, Mix 6.

DETAILED DESCRIPTION OF THE INVENTION

[0033] As per the presented figures, this invention refers to a method for obtaining a high-performance aqueous-phase polymer fluid for drilling wells in low gradient formations, consisting of preparing a significant volume (70 m.sup.3) in the shortest time possible with theological possibilities (Viscosity) as shown in the graph of FIG. 5.

[0034] The reason the quantity is 70 m.sup.3 or more is because, during drilling operations, 70 m.sup.3 to 120 m.sup.3 are pumped per hour, depending on the required volumes for drilling; this in order to achieve drilling without having to suspend it due to lack of materials or volume. A test of the reduced volume is shown in FIG. 1.

[0035] The elimination of polymer clots also known as “fish eyes” is a priority during the high performance aqueous-phase polymer fluid preparation, since during formation, one must wait until there is a complete incorporation of the polymer or products to the system in order to avoid pumping equipment damage and blockage of the strainers of directional tools. For this reason, the use of rapid wetting polymers is important in the reduction of preparation times.

[0036] When preparing a high performance aqueous-phase polymer fluid as quickly as in this method, longer stirring times are used often in order to ensure that homogenization and dilution of products has been adequate, and increasing preparation times; therefore, in the method of this invention, a clay inhibitor easily incorporated to the system is used thereby achieving the stirring for 5 minutes at the end of water and last product aggregation (time adjustment to a total of half an hour), to be correctly inhibited.

[0037] Although all fluids must comply with different regulations of water-based fluids, this fluid, which is obtained by the process of this invention, is characterized by being manufactured with few materials (five products), that in this case are liquid products and that have been evaluated to have electrochemical affinity when mixing that allows a uniform and quick mixture preparation while also complying with the inhibition, viscosity, lubricity, and rheology requirements, FIG. 7.

[0038] During customer validation of drilling fluids, the established requirements in the rock fluid interaction must be complied with, in this interaction the system easily provides clay inhibitions up to 30 CEC, FIG. 7. In addition, unlike other systems, this physicochemical property can be easily given.

[0039] The method of the current invention needs to add, in certain stages and with certain operation characteristics, a number of chemical compounds that make up a high performance aqueous-phase polymer fluid for drilling of wells in low-gradient formations; therefore, the following table indicates such compounds, their role, as well as the mixing quantities:

TABLE-US-00001 Chemical material Concentration in L/m.sup.3 Seawater/continuous phase 974.80-966.30 Amine corrosion inhibitor 1.80-2.50 Amine glycol & KCl mixture inhibitor 5.40-7.20 Xanthan gum (viscosifier)  8.10-10.80 Polyanionic Cellulose Polymer (filtration reducer) 7.20-9.60 Polyacrylamide (clay stabilizer) 2.70-3.60

[0040] Each of these components has the function of mixing easily in an established order, without reacting to each other and interacting with the available continuous phase (Aqueous), up to 100% of the continuous phase, in such a way that there is no free continuous phase interacting with the clays or formations without being previously inhibited during the moistening process of the other components.

[0041] During the application of this aqueous-phase polymer fluid in the Cantarell-3017D well; It was demonstrated that the most important, novel and inventive differences in the method of the present invention were as follows: [0042] a) The preparation time showed 70 m.sup.3 can be manufactured in only 30 minutes as shown in FIG. 5 [0043] b) Reduction of consumed volume up to 50% regarding the volume consumed with other systems. FIG. 1. [0044] c) Drilling time improved up to 77%, FIG. 2. [0045] d) The use of support vessels to prepare and pump fluid was eliminated. [0046] e) The logistic travels of vessels was reduced by 50%, as shown in FIG. 3. [0047] f) The rate of penetration (ROP) was increased due to the high theological Properties. FIG. 2. [0048] g) For the preparation of viscous sweeps of 200 sec.: 5 m.sup.3 in 5 minutes. [0049] h) The pre-treatment time for seawater is eliminated, as shown in FIG. 4 [0050] i) Provides 0.22 lubricity, increasing ROP, as illustrated in FIG. 6 [0051] j) Improves the performance of directional motors. [0052] k) Eliminates the generation of wastes in bags. [0053] l) Well finished to gauge.

[0054] Preparation Method of Well Drilling Fluids

[0055] The high performance aqueous-phase polymer fluid preparation process must be formulated and designed to meet the requirements needed for well drilling. Before preparing the fluid, the mud dams must be cleaned. It is necessary to check the valves of non-communicated dams. More specifically, the following points should be taken into account: [0056] 1.—Resource preparation [0057] 2.—Resource mobilization [0058] 3.—System preparation [0059] 4.—System quality verification [0060] 5.—Field laboratory equipment [0061] 6.—Laboratory equipment with special tests

[0062] Resource Preparation:

[0063] For large-scale system preparation, tank systems or conventional dams, as those in the drilling equipment, which meet the minimum requirements, are necessary; [0064] a) Mixing dams of 45 m3 minimum capacity [0065] b) 45 HP centrifuge pumps [0066] c) 3 kpascal air compressor [0067] d) 2 pumps with a pumping capacity of 275 gpm (Diaphragm or Variable speed pump). [0068] e) Suction and exhaust hoses resistant to chemical products and hydrocarbon byproducts. [0069] f) Heavy-duty bronze quick connections [0070] g) Air hoses with connections

[0071] 2.—Resource Mobilization

[0072] Once verifying the resources on the checklist prior to operations, document submission to Pemex (shipment notices) must be conducted to complete the shipping to the required site.

[0073] 3.—System Preparation

[0074] Preparation of drilling fluids. The preparation method of the high performance aqueous-phase polymer fluid must be formulated and designed to meet the requirements needed for well drilling. Before preparing the fluid, mud preparation tanks or dams must meet the following requirements: [0075] They must be clean and free of the fluid residues mentioned above. [0076] They must avoid the connection between dams by means of suction valves or chambers from the same building. [0077] The preferred agitation system is electro-mechanical agitation by means of beaters and agitators of turbines. [0078] Stirring must be uniform across the whole volume of the tank or dam; if available, use down-hole guns to streamline the homogeneous incorporation of polymers.

[0079] 4.—System Quality Verification, as per the API RP 13B-1 Method.

[0080] The laboratory tests with samples of correlation well formations of the breccia from Ku, Maloob, Zaap, and Cantarell fields, and the high performance aqueous-phase polymer fluid formation are carried out evaluating the following parameters:

[0081] Fluid stability [0082] Fluid density (glee) [0083] Marsh viscosity (sec.) [0084] API plastic viscosity. [0085] API yield point. [0086] Low-shear rate yield point (LSRYP). [0087] 0′ gel [0088] 10′ gel [0089] API filtering. [0090] Water and solids content (%). [0091] Chemical analysis (mud alkalinity, filtrate alkalinity, salinity, calcium ions content)

[0092] Rock-Fluid Interaction Tests

[0093] In the event that a study on the behavior of the rock-fluid interaction is required, the tests stated in this section will be performed.

[0094] These tests require shearings of formations, cores, or synthetic pills (A-C, A′-C′), of equal formation reactivity. The following interaction tests are performed with the preparation of the high performance aqueous-phase polymer fluid: [0095] Linear swelling, as shown in FIG. 8. [0096] Dispersion, as shown in FIG. 9. [0097] CEC determination (Cationic Exchange Capacity in meq/100 g of day sample) of the clays used for the tests, see. FIGS. 10 and 11.

[0098] Thus, a preferred modality for the method of this invention in order to prepare a high performance aqueous-phase polymer liquid comprises the following stages: [0099] a. Provide a darn or tank (T) with stirring system; [0100] b. Provide a deep-well pump (71); [0101] c. Provide a diaphragm pump (72) and suction and discharge hoses; [0102] d. Provide a stabilizing container of clays (70a-70e); [0103] e. Provide a container of filtration reducer (70a-70e); [0104] f. Provide a container of glycol Amine mixture inhibitor (70a-70e); [0105] g. Using the deep-well pump, add seawater to a selected dam or tank for the preparation up to 80% of its capacity, 974.80-966.30 liters/m.sup.3, and employing the stirring system of the dams or tanks; [0106] h. With the 3″ diaphragm suction and discharge pump with pumping capacity of 237 gal/min, model PD30X-XXX-C, and hoses with a 3″ diameter and 15 meters length, each hose reinforced with steel for managing a pressure of 250 psi with fast connections at the ends, located in the bomb suction and discharge, the products for the formulation of high performance aqueous-phase polymer fluid will be pumped into the dam or tank, where preparation tanks having 70 cm blade stirrers (4 blades total), with a 50-70 rpm torque and a 30 HP electrical motor will be continuously stirring the preparation tanks of the high performance aqueous-phase polymer liquid in their respective sites. Add a viscosifier as xanthan gum to reach a concentration of 8.10-10.80 liters/m.sup.3; [0107] i. Place the suction diaphragm pump in the clay stabilizer (Dispersion), and pump the product to reach a concentration of 2.70-3.60 liters/m.sup.3, continue with system stirring; [0108] j. Place the suction of the pump in the filtering reducer container, and pumping to achieve in a concentration of 7.20-9.60 liters/m.sup.3 and continue the stirring process; [0109] k. With support of the diaphragm pump, continue with the addition of corrosion inhibitor up to a concentration of 1.80-2.50 liters/m.sup.3 and continue mixing the system; [0110] l. Place the suction in the inhibitor mixture amine glycol and pump the clay inhibitor (Swelling), in a concentration of 5.40-7.20 liters/m.sup.3 and continue stirring the system; [0111] m. If permitted by the operation, complete the 30-minute stirring time of system after adding all the material.

[0112] The continuous stirring time of the system is set to 30 minutes from the beginning of products pumping to have a homogeneous mixture of the high performance aqueous-phase polymer fluid, and pump the well with pump (73) of the equipment (e.g.: 6″×12″ triplex pump, national oil well®), to carry out the drilling operations. This method also involves a mixing pump (74).

[0113] The method to form a high performance aqueous-phase polymer fluid is designed to have the physicochemical properties necessary to carry out the drilling function, for which it is designed, since its preparation.

[0114] In addition, this invention provides a drilling system using a high performance aqueous-phase polymer fluid obtained from the inventive method, comprising: mixing channels of minimum capacity of 45 m3; centrifugal pumps of 45 HP; 3 kpascal air compressor; 2 pumps with pumping capacity of 275 gpm. (Diaphragm or Variable Speed Pump); suction and discharge hoses resistant to chemicals and hydrocarbon byproducts; Heavy-duty bronze connections and air hoses with connections.

[0115] Based on the above, it can be noted that, even though specific arrangements of the invention have been described in this document for illustrating purposes, several modifications can be made without diverting from the essence and scope of the invention. As a result, the invention has no limitations except the ones stated in the attached claims.