CONDENSATE RECOVERY UNIT
20220062811 · 2022-03-03
Inventors
- Travis O. DINSDALE (Calgary, CA)
- James KADAR (Calgary, CA)
- Jonathan J. KIESEWETTER (Calgary, CA)
- Dale L. Embry (Houston, TX, US)
Cpc classification
B01D3/143
PERFORMING OPERATIONS; TRANSPORTING
B01D5/0003
PERFORMING OPERATIONS; TRANSPORTING
B01D5/006
PERFORMING OPERATIONS; TRANSPORTING
B01D5/0036
PERFORMING OPERATIONS; TRANSPORTING
International classification
B01D53/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
Production equipment and methods which reduce “gray” or off-specification production and improve central processing facility (CPF) efficiency. The process is a combination of unit operations (heat exchange, pumping, and separation) to produce an on-spec gas product, an on-spec condensate product, and/or on-spec oil product. It does so by placing the feed under pressure and heating it to the point that it can be vaporized and separated. The blended components are modulated dependent upon the composition of the produced fluids, produced gas, and off-specification fluid to efficiently produce on-specification products.
Claims
1. A process for treating produced fluids that are off specification where the process comprises: a) receiving an off-specification fluid from one or more production wells; b) heating said off-specification fluid to a first flashing temperature wherein one or more components in said off-specification fluid will vaporize; c) flashing said off-specification fluid in a pseudo-separator to create a first gas stream and a first liquid stream; d) blending one or more streams selected from the first gas stream, a produced gas, a flashed liquid, or a produced liquid to create an on-specification stream; and e) optionally blending one or more streams selected from the first gas stream, a produced gas, a flashed liquid, or a produced liquid to create one or more additional on-specification streams wherein said blended components are modulated dependent upon the composition of the produced fluids, produced gas, and off-specification fluid.
2. The process according to claim 1, wherein said off-specification fluid is heated in a heat exchanger with a flashed gas stream, flashed liquid stream, a condensate gas stream, a light condensate liquid stream, or a light oil stream
3. The process according to claim 1, wherein said on-specification blended stream consists essentially of a condensate, a light gas condensate, a light oil condensate, a light oil, fuel gas, heater oil, or oil.
4. The process according to claim 1, wherein said on-specification stream is a gas of sufficient quality to deliver to said gas sales pipeline.
5. The process according to claim 1, wherein said on-specification stream is a liquid of sufficient quality to deliver to said liquid sales pipeline.
6. The process according to claim 1, where the process further comprises: d) following step (c), heating the first liquid stream to a second flashing temperature; e) flashing said first liquid stream to create a second gas stream and second liquid stream; wherein: step (d) comprises blending one or more streams selected from the first gas stream, second gas stream, first liquid stream, produced gas, produced liquid, and combinations thereof to create a first on-specification product; and step (e) is performed and comprises blending one or more streams selected from the first gas stream, second gas stream, first liquid stream, produced gas, produced liquid, and combinations thereof to create a second on-specification product wherein said blended components are modulated dependent upon the composition and measured physical properties of the produced fluids, produced gas, and off-specification fluid.
7. A process for treating produced fluids that are off-specification where the process comprises: a) receiving an off-specification fluid from one or more production wells; b) heating said off-specification fluid to a first flashing temperature wherein one or more components in said off-specification fluid will vaporize; c) flashing said off-specification fluid in a pseudo-separator to create a first gas stream and a first liquid stream; d) heating the first liquid stream to a second flashing temperature; e) flashing said first liquid stream to create a second gas stream and second liquid stream f) blending one or more streams selected from the first gas stream, second gas stream, first liquid stream, produced gas, produced liquid, and combinations thereof to create a first on-specification product; and g) blending one or more streams selected from the first gas stream, second gas stream, first liquid stream, produced gas, produced liquid, and combinations thereof to create a second on-specification product wherein said blended components are modulated dependent upon the composition and measured physical properties of the produced fluids, produced gas, and off-specification fluid.
8. The process according to claim 7, wherein said off-specification fluid is heated in a heat exchanger with a flashed gas stream, flashed liquid stream, a condensate gas stream, a light condensate liquid stream, or a light oil stream
9. The process according to claim 7, wherein said on-specification blended stream consists essentially of a condensate, a light gas condensate, a light oil condensate, a light oil, fuel gas, heater oil, or oil.
10. The process according to claim 7, wherein said on-specification stream is a gas of sufficient quality to deliver to said gas sales pipeline.
11. The process according to claim 7, wherein said on-specification stream is a liquid of sufficient quality to deliver to said liquid sales pipeline.
12. A process for treating produced fluids that are off-specification where the process comprises: a) receiving an off-specification fluid from one or more production wells; b) preheating said off-specification fluid to generate a heated off-specification fluid; c) heating said heated off-specification fluid to a second temperature wherein one or more components in said off-specification fluid will vaporize; d) distilling said heated off-specification fluid in a distillation column to create a condensate gas stream, a light condensate liquid stream, and a bottom light oil stream; and e) blending one or more streams selected from the condensate gas stream, light condensate liquid stream, bottom light oil stream, a produced gas, or a produced liquid to create one or more on-specification fluid streams, wherein said blended components are modulated dependent upon the composition of the produced fluids, produced gas, and off-specification fluid.
13. The process according to claim 12, wherein said off-specification fluid is heated in a heat exchanger with a flashed gas stream, flashed liquid stream, a condensate gas stream, a light condensate liquid stream, or a light oil stream
14. The process according to claim 12, wherein said on-specification blended stream consists essentially of a condensate, a light gas condensate, a light oil condensate, a light oil, fuel gas, heater oil, or oil.
15. The process according to claim 12, wherein said on-specification stream is a gas of sufficient quality to deliver to said gas sales pipeline.
16. The process according to claim 12, wherein said on-specification stream is a liquid of sufficient quality to deliver to said liquid sales pipeline.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. A more complete understanding of the present invention and benefits thereof may be acquired by referring to the follow description taken in conjunction with the accompanying drawings.
[0021]
[0022]
[0023]
[0024]
[0025]
[0026]
[0027]
[0028]
DETAILED DESCRIPTION
[0029] Turning now to the detailed description of the preferred arrangement or arrangements of the present invention, it should be understood that the inventive features and concepts may be manifested in other arrangements and that the scope of the invention is not limited to the embodiments described or illustrated. The scope of the invention is intended only to be limited by the scope of the claims that follow.
[0030] This process is a combination of unit operations (heat exchange, pumping, and separation) to produce an on-spec condensate product and heavier crude oil product, as well as side stream products that may be recovered for sales or used for blending of sales products. It does so by placing the feed under pressure and heating it to the point that it can be vaporized and separated (flashed). Further refinement of the flashed liquid by partially vaporizing and fractionating in an atmospheric distillation column produces a heavy (in terms of density and/or viscosity) product from the bottom of the column, a lighter naphtha rich product from the column overhead and an intermediate product from the column pump around side draw. Condensation of the vapor from the initial flash vessel (pre flash drum) and the distillation column overhead followed by blending with the side draw pump around product produces a low density, low viscosity naphtha rich diluent stream that can be blended with heavy stabilized condensate to produce an on specification sales condensate and/or blended with the column bottoms product to produce an on specification light oil product. In summary, by treating a heavy (in terms of density and/or viscosity) stabilized condensate product an on-specification condensate product and crude oil residual product are created.
[0031] As shown in
[0032] The example shown in
[0033] In one embodiment, the Well Pads 101 may have local facilities for producing the wells and for the blending of water and chemicals for fracking operations, enhanced oil recovery, well treatments, and the like. Raw production from the wells may include sour gas, gas, hydrocarbon liquids, and produced/flow back water. These produced materials are typically metered as they are produced and either stored at the well pad or transported directly to the CPF for processing. The Well Pads 101 may be supplied water, fuel, electricity, and other needs from the CPF or some materials may be delivered, stored on location, or provided via other sources.
[0034] In one embodiment, the CPF may process all incoming raw gas, hydrocarbon liquids and produced/flow back water to generate sales products such as sweet natural gas, NGL (C3+) and Condensate (C5+). The sales gas will be directed to the SPL system where NGL is metered and transferred to a SPL, Condensate products is pipelined to a condensate SPL. Produced/Flow back water from the CPF may be directed to a WH for treatment, storage, recycling, and/or disposal.
[0035]
[0036] Increases in produced fluid density have a cascading effect throughout the production process. Slightly heavier inlet liquids lead directly to an increase in Stabilized Condensate density. Increasing Stabilized Condensate density, may lead to increased loads on the Stabilizer Reboiler and Product Cooler. The material balance through the system may be shifted, leading to decreases in Stabilizer Recycle Compressor need. These changes in equipment demand and produced product lead to unpredictable needs and products.
[0037] The following examples of certain embodiments of the invention are given. Each example is provided by way of explanation of the invention, one of many embodiments of the invention, and the following examples should not be read to limit, or define, the scope of the invention.
[0038] One possible way to reduce grey “off spec” product is to convert the grey product into saleable product(s). A condensate stabilization system may be used to remove volatile components and dissolved gasses from the condensate to ensure compliance with product specifications for vapor pressure and/or volatile component concentrations. After stabilization, the condensate product will typically display a higher density and viscosity, and may no longer meet the product specification for sales condensate, typically dictated by a kinematic viscosity of <2 cSt at 7.5° C. measured by ASTM D 7042 and a standard liquid density of between 600 kg/m3 to 775 kg/m3 measured by ASTM D 4052. After stabilization, if the condensate product no longer meets the applicable sales condensate specification, further processing may be necessary to fractionate the whole stabilized condensate stream, or a fraction of the stabilized condensate stream, to produce a sales condensate product with a higher composition of lower molecular weight hydrocarbons, and a residual light oil product that is enriched in higher molecular weight hydrocarbons. The new system should be designed to maximize the Condensate production while keeping below the 2 cSt kinematic viscosity specification. Optimization can be used to reduce equipment loads and tower sizes. The condensate recovery unit may also incorporate stabilization of the live condensate product in place of or interlinked with the distillation column pre-flash function.
EXAMPLE 1
Single Stage Heat and Flash
[0039] In this scheme the liquids are first heated to about 575° F. and then sent to a flash separator. The overhead “gas” stream is then condensed back down to produce the Light Condensate product. Whereas, the bottom liquid stream is cooled to produce the Light Oil product.
TABLE-US-00002 TABLE 2 Single Flash Configuration Summary Parameter Units Design Simulation Process Streams Inlet Stream Total HC Liquids BPD 18,180 Inlet HC Liquids Std. Density kg/m3 780.6 Light Condensate Product Flow BPD 13,120 RVP kpaa @ 37.8 C 64.6 Std. Density kg/m3 756 Kinematic Viscosity (@7.5 C) cSt 1.426 Light Oil Product Flow BPD 4863 Std. Density kg/m3 878.4 Oil Fractionation System Feed/Condensate Exchanger Duty MMBtu/hr 24.8 UA Btu/F-hr 138,000 Feed Fired Heater Duty MMBtu/hr 42.5 Flash Vessel 1 Estimated Diameter ft 7.5 Vessel Length ft 28 Light Condensate Cooler Duty MMBtu/hr 34.6 Light Oil Product Cooler Duty MMBtu/hr 19.4
[0040] As detailed in
EXAMPLE 2
Two-stage Heat and Flash
[0041] The next iteration utilized a Two-stage Heat and Flash scheme with some cross exchangers to minimize external heat inputs. This scheme is unique in that it provides 3 product coolers and 2 external heaters. This type of system can produce approximately 12,430 BPD of Light Condensate and 5500 BPD of Light Oil. As above,
TABLE-US-00003 TABLE 3 Two Stage Flash Configuration Parameter Units Design Simulation Process Streams Inlet Stream Total HC Liquids BPD 18,180 Inlet HC Liquids Std. Density kg/m3 780.6 Light Condensate Product Flow BPD 13,100 RVP kpaa @ 37.8 C 65.06 Std. Density kg/m3 756.6 Kinematic Viscosity (@7.5 C) cSt 1.456 Light Oil Product Flow BPD 4908 Std. Density kg/m3 872.5 Oil Fractionation System Feed/Condy Exchanger 1 Duty MMBtu/hr 13.6 UA Btu/F-hr 24,200 Feed Fired Heater 1 Duty MMBtu/hr 17.4 Flash Vessel 1 Estimated Diameter ft 10 Vessel Length ft 35 Feed/Candy Exchanger 2 Duty MMBtu/hr 22.9 UA Btu/F-hr 191,000 Feed Fired Heater 2 Duty MMBtu/hr 31.9 Flash Vessel 2 Estimated Diameter ft 7 Vessel Length ft 24 Light Condensate Cooler Duty MMBtu/hr 36.9 Light Oil Product Cooler Duty MMBtu/hr 22.3
[0042] As shown in
EXAMPLE 3
Distillation Column Separation
[0043] Additionally, a distillation column may be used to separate the Light Condensate from the Light Oil. The column design basis was to produce approximately 13,000 BPD of Light Condensate and about 5000 BPD of Light Oil.
TABLE-US-00004 TABLE 4 Distillation Tower Configuration Summary Parameter Units Example Values Process Streams Inlet Stream Total HC Liquids BPD 18,180 Inlet HC Liquids Std. Density kg/m3 780.6 Light Condensate Product Flow BPD 13,100 RVP kpaa @ 37.8 C 64.7 Std. Density kg/m3 756.1 Kinematic Viscosity (@7.5 C) cSt 1.431 Light Oil Product Flow BPD 4916 Std. Density kg/m3 875 Oil Fractionation System Feed/Bottoms Exchanger Duty MMBtu/hr 17 UA Btu/F-hr 159,000 Feed Fired Heater Duty MMBtu/hr 55 Distillation Tower Tower Number of Trays 5 Estimated Diameter ft 6 and 7 Reflux Ratio 5 Condenser Duty MMBtu/hr 53.3 Light Oil Pump Duty bhp 10 Light Oil Product Cooler Duty MMBtu/hr 4.1
[0044]
[0045] As shown in
[0046]
[0047] In
[0048]
EXAMPLE 4
Metered
[0049] In another embodiment, the produced fluid is monitored using an inline meter. The inline meter may be a Spectrophotometer, GCMS, and/or another analyzer may be used. Additionally, identifying production rates from a variety of individual wells or well pads that feed into the CPF may be used to estimate the amount of grey product produced. In this way, the amount of fluids passed through one of the previously demonstrated facilities may be increased or decreased dependent upon need. In one embodiment, a Grey Produced Fluid and a New Oil are mixed to create an on-specification Light Oil. In another embodiment a Grey Produced Fluid and a New Condy are mixed to create an on-specification Light Condensate. By characterizing all necessary “Representative Samples” blending evaluations can be used to determine both the produced fluid along with blending fluids that may shift the produced fluid from a grey fluid to a desired product.
[0050] As production is increased, new wells, and new well pads are added to the CPF, the overall mix may be changed dynamically. This coupled with decreasing production rates and changing products in over the life of each well creates a situation where the produced fluid composition cannot be guaranteed throughout the life of the field. By optimizing the rate of flash drum or distillation, the use of an oil heater can be minimized formulaically to reduce fuel oil use while maximize on-specification product production and rates.
[0051] In closing, it should be noted that the discussion of any reference is not an admission that it is prior art to the present invention, especially any reference that may have a publication date after the priority date of this application. At the same time, each and every claim below is hereby incorporated into this detailed description or specification as a additional embodiments of the present invention.
[0052] In one embodiment a spectrophotometer, gas analyzer, GCMS, or other tool may be used to characterize the presence and need for blending or changes in flash temperature. By monitoring produced fluid properties, the flash drum temperature may be adjusted, produce fluid can be compensated for, and blending agents may be adjusted to shift the produced fluid from light oil to produce a Condensate Product stream which may be sold to one or more commercial pipelines.
[0053] In closing, it should be noted that the discussion of any reference is not an admission that it is prior art to the present invention, especially any reference that may have a publication date after the priority date of this application. At the same time, each and every claim below is hereby incorporated into this detailed description or specification as additional embodiments of the present invention.
[0054] Although the systems and processes described herein have been described in detail, it should be understood that various changes, substitutions, and alterations can be made without departing from the spirit and scope of the invention as defined by the following claims. Those skilled in the art may be able to study the preferred embodiments and identify other ways to practice the invention that are not exactly as described herein. It is the intent of the inventors that variations and equivalents of the invention are within the scope of the claims while the description, abstract and drawings are not to be used to limit the scope of the invention. The invention is specifically intended to be as broad as the claims below and their equivalents.
REFERENCES
[0055] All of the references cited herein are expressly incorporated by reference. The discussion of any reference is not an admission that it is prior art to the present invention, especially any reference that may have a publication data after the priority date of this application. Incorporated references are listed again here for convenience: [0056] 1. CA2904901 (Ploeger, et al.), “Membrane Separation of Carbon Dioxide from Natural Gas with Energy Recovery,” 2016 [0057] 2. U.S. Pat. No. 6,357,526 (Abdel-Halim, et al.), “Field Upgrading of Heavy Oil and Bitumen” (2002).