A pressurized huff and puff oil washing unit suitable for tight shale

Abstract

The utility model provides a kind of to be suitable for compact mud shale's pressurized throughput oil washing device, including oil washing tank, solvent chamber, air compressor, vacuum pump and booster pump;The sample of oil to be washed is contained in the oil washing tank;The first interface of oil washing tank is located in side portion, and is communicated with first pipeline;The second interface of oil washing tank is located in top portion, and is communicated with second pipeline, and the third interface of oil washing tank is located in top portion, and is communicated with third pipeline;The upper portion and lower portion of the oil washing tank are provided with external circulating pipeline, and circulating pump is arranged on circulating pipeline;The bottom of the oil washing tank is provided with booster pump by pipeline;The solvent chamber is communicated with first pipeline by pipeline.The beneficial effects of the utility model are that oil washing action can be carried out in room temperature environment, and the problem of sample cracking in repeated hot and cold alternating environment can be effectively avoided, so that the success rate of sample after oil washing is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of shale oil and gas exploration and development technology, specifically to a pressurized huff and puff washing device suitable for dense mudstone and shale. Background Technology

[0002] In shale oil exploration, downhole samples obtained from exploratory wells, such as drilling cuttings and core samples, serve as crucial windows for geologists to conduct geological research and understanding. Geological sample analysis, due to its intuitiveness, uniqueness, and irreplaceability, has become an important aspect of geological research, making precise analysis of various parameters of these samples essential. Analysis of shale porosity, permeability, rock pore characteristics, microscopic identification, reservoir flowability, and sensitivity experiments all require analysis of these shale rocks. These analyses and experiments must be conducted without damaging the original structure of the core. Drilling cuttings and core samples contain a certain amount of crude oil, which is contained in different states within the shale pores. Because shale is both a source and reservoir, it is characterized by extremely low permeability, tightness, and well-developed laminae. Furthermore, some shale formations contain soluble salt minerals. Therefore, different regions and different types of tight shale require different oil washing methods.

[0003] Currently, existing oil washing methods include solenoid extraction and high-pressure displacement. Solenoid extraction involves repeated heating and cooling of the solvent in the sample, which can easily cause cracking and render the sample unusable, especially for samples containing soluble salt minerals or well-laminated mudstone and shale. Due to the low porosity and permeability of mudstone and shale, the oil washing time for dense samples can be as short as one month or as long as six months, resulting in very low work efficiency. High-pressure displacement may cause particle migration in the sample, altering the porosity of the sample and affecting the accuracy of the test results.

[0004] In summary, existing oil washing methods have several drawbacks, including the potential to alter the properties of the core, low success rate, and long washing cycles when the core is dense, which severely impact the research cycle and the quality of the results. Furthermore, existing oil washing methods also suffer from drawbacks such as large solvent consumption, low efficiency, high energy consumption, significant safety risks, and environmental unfriendliness. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a pressurized sluice-mass oil washing device suitable for dense mudstone, aiming to solve the problem of cracking during sample re-washing in existing technologies.

[0006] The technical solution of this utility model is: a pressurized huff and puff oil washing device suitable for dense mudstone and shale, including an oil washing tank, a solvent chamber, a circulation pump and a booster pump;

[0007] The washing tank contains a sample of the oil to be washed;

[0008] The first interface of the washing tank is located on the side and is connected to the first pipeline; the second interface of the washing tank is located on the top and is connected to the second pipeline; the third interface of the washing tank is located on the top and is connected to the third pipeline.

[0009] The upper and lower parts of the washing tank are equipped with external circulation pipelines, and circulation pumps are installed on the circulation pipelines.

[0010] A booster pump is installed at the bottom of the washing tank via a pipeline;

[0011] The solvent chamber is connected to the first pipeline via a pipeline;

[0012] A viewing window is provided on the third pipeline.

[0013] According to the above scheme, the pressurized huff and puff oil washing device suitable for dense mudstone and shale is also equipped with a liquid storage tank. The solvent chamber is connected to the bottom of the liquid storage tank through a pipeline, and the outlet of the liquid storage tank is connected to the first pipeline.

[0014] According to the above scheme, a secondary pump and a check valve are arranged on the second pipeline.

[0015] According to the above scheme, the pressurized huff and puff washing oil device suitable for dense mudstone and shale is also equipped with a condensation chamber. The cold source channel of the condensation chamber is connected to the cold source inlet pipe and the cold source outlet pipe respectively; the heat source outlet of the condensation chamber is connected to the liquid storage tank and the solvent chamber respectively through pipelines.

[0016] According to the above scheme, the pressurized flushing oil washing device is also equipped with a vacuum pump, which is connected to the second pipeline through the fifth pipeline.

[0017] According to the above scheme, a buffer tank is also installed on the fifth pipeline.

[0018] According to the above scheme, the pressurized flushing oil washing device is also equipped with an air compressor, which is connected to the second pipeline through the fourth pipeline.

[0019] According to the above plan, two buffer tanks are sequentially installed on the fifth pipeline.

[0020] According to the above scheme, the cold source for the condensing chamber is condensate.

[0021] The beneficial effects of this utility model are as follows:

[0022] This invention provides a pressurized huff-and-puff oil washing device suitable for dense mudstone and shale. It includes an oil washing tank, a solvent chamber, a circulation pump, and a booster pump, allowing oil washing to be performed at room temperature. Compared to existing technologies, it effectively avoids sample cracking caused by repeated hot and cold cycles, significantly improving the success rate of sample washing and saving washing time, thus increasing efficiency. This invention specifically selects the oil washing solvent to effectively prevent breakage of salt-containing samples during the washing process. The high-pressure huff-and-puff method effectively increases the speed at which the oil washing solvent enters the sample pores and the speed at which crude oil is washed out, resulting in high-quality oil washing and significantly improved production efficiency. Attached Figure Description

[0023] Figure 1 This is a structural schematic diagram of a specific embodiment of the present invention.

[0024] The components are as follows: 1. Washing oil tank; 2. Vacuum pump; 3. Buffer tank; 4. Circulation pump; 5. Solvent chamber; 6. Liquid storage tank; 7. Condensation chamber; 8. Viewing window; 9. Check valve; 10. Booster pump; 11. Auxiliary pump; 12. Air compressor; 13. First pipeline; 14. Second pipeline; 15. Third pipeline; 16. Fourth pipeline; 17. Fifth pipeline; V1~V9 are all valves. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] In the description of the embodiments of this application, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0028] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0029] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples, without contradiction. Additionally, the term "a plurality of" indicates two or more.

[0030] like Figure 1 The pressurized huff and puff washing device shown is suitable for dense mudstone and shale, including washing tank 1, solvent chamber 5, circulation pump 4 and booster pump 10;

[0031] The washing tank 1 contains a dense mudstone and shale sample to be washed.

[0032] The first interface of the washing tank 1 is located on the side and is connected to the first pipeline 13; the second interface of the washing tank 1 is located on the top and is connected to the second pipeline 14; the third interface of the washing tank 1 is located on the top and is connected to the third pipeline 15.

[0033] The upper and lower parts of the washing tank 1 are provided with external circulation pipelines, and the circulation pipelines are equipped with circulation pumps 4.

[0034] A booster pump 10 is installed at the bottom of the washing tank 1 via a pipeline;

[0035] The solvent chamber 5 is connected to the first pipeline 13 via a pipeline and is used to provide washing oil solvent to the washing oil tank 1.

[0036] The third pipeline 15 is equipped with a viewing window 8.

[0037] In this invention, each pipeline is equipped with a valve, as shown in the attached drawing V1~V9; the outlet of the third pipeline 15 is connected to the solvent chamber 5.

[0038] Preferably, the pressurized huff and puff washing device suitable for dense mudstone and shale is further provided with a storage tank 6, the solvent chamber 5 is connected to the bottom of the storage tank 6 through a pipeline, and the outlet of the storage tank 6 is connected to the first pipeline 13.

[0039] In this invention, the washing oil solvent in solvent chamber 5...

[0040] In this invention, a secondary pump 11 and a check valve 9 are arranged on the second pipeline 14.

[0041] Preferably, the pressurized huff and puff washing oil device suitable for dense mudstone and shale is further provided with a condensation chamber 7, the cold source channel of the condensation chamber 7 is connected to the cold source inlet pipe and the cold source outlet pipe respectively; the heat source inlet of the condensation chamber 7 is connected to the washing oil solvent outlet of the solvent chamber 5, and the heat source outlet of the condensation chamber 7 is connected to the liquid storage tank 6 and the solvent chamber 5 respectively through pipelines.

[0042] In this invention, the cold source in the cold source channel of the condensing chamber 7 is condensate. The condensing chamber 7 is used to cool the clean wash oil solvent distilled from the solvent chamber 5, and then send the cooled wash oil solvent into the solvent chamber 5 or the storage tank 6. The design of the condensing chamber 7 can improve the reuse efficiency of the wash oil solvent, save solvent consumption, and reduce costs. The cold source is condensate.

[0043] Preferably, the pressurized spit-and-swallow oil washing device is further equipped with a vacuum pump 2, which is connected to the second pipeline 14 via the fifth pipeline 17.

[0044] In this invention, starting the vacuum pump 2 to evacuate the liquid storage tank 6 can accelerate the injection of the washing oil solvent from the liquid storage tank 6 into the washing oil tank 1.

[0045] Preferably, a buffer tank 3 is also provided on the fifth pipeline 17. Specifically, two buffer tanks 3 are arranged in sequence on the fifth pipeline 17.

[0046] In this embodiment, two washing oil tanks 1 are set up. The two washing oil tanks 1 are configured the same, each with three interfaces and three pipelines. The connection and configuration of the three pipelines are the same. The configuration of the buffer tank 1 can effectively prevent the washing oil solvent from being directly sucked into the vacuum pump 2.

[0047] Preferably, the pressurized flushing oil washing device is further provided with an air compressor 12, which is connected to the second pipeline 14 through the fourth pipeline 16.

[0048] In this invention, the air compressor 12 is used to return all the washing oil solvent in the washing oil tank 1 to the solvent chamber 5 through the third pipeline 15 with the viewing window 8.

[0049] In this utility model, the washing tank 1, vacuum pump 2, solvent chamber 5, liquid storage tank 6, air compressor 12 and other equipment are all existing mature equipment in the industry; other equipment not described in detail are all conventional technologies.

[0050] An experimental method for washing shale oil based on the pressurized huff and puff washing device described above, the method comprising the following steps:

[0051] S1. Provide a pressurized huff and puff washing unit for dense mudstone and shale as described above.

[0052] S2. Obtain experimental samples, analyze the properties of each sample, label them separately, and then air dry them.

[0053] In this invention, the experimental samples obtained are dense mudstone and shale samples. These samples may have well-developed bedding and contain soluble rock salts, or they may be extremely dense. Unprocessed rock fragments, small block samples, or prepared columnar samples can be selected. Before oil washing, existing technologies are used to analyze these geological samples to determine their stratigraphic origin, degree of bedding development, and general mineral composition, thus obtaining the properties of each sample. The methods for obtaining and analyzing these samples are existing mature technologies in the industry and will not be elaborated upon here.

[0054] In this embodiment, a dense mudstone and shale sample with well-developed lamellar structure and containing soluble rock salt was selected for the experiment.

[0055] S3. Select different washing solvents and washing processes according to different sample properties. Put the washing solvent into the solvent chamber 5 in sufficient quantity in advance. The washing solvent in the solvent chamber 5 can enter the storage tank 6 through the pipeline.

[0056] In this embodiment, sufficient washing solvent means that the washing solvent in the storage tank 6 is maintained at more than 80% of its volume, as indicated by observing the liquid level gauge. Different washing solvents are selected according to the different properties of the samples. Specifically, for mudstone and shale samples with well-developed laminae and containing soluble salt minerals, chloroform is selected as the washing solvent; for dense mudstone and shale samples with well-developed laminae, an alcohol-benzene binary solvent can be selected as the washing solvent.

[0057] S4. Place the samples in the sample basket in an orderly manner, and then put them into the oil washing tank 1.

[0058] In this invention, when the sample quantity is large, two washing tanks 1 can be used to operate simultaneously; when the sample quantity is small, only one washing tank 1 needs to be used to load the sample.

[0059] S5, open the valve on the first pipeline 13, start the auxiliary pump 11, and add the washing oil solvent from the storage tank 6 to the washing oil tank 1; and pre-set the pressure rise and fall, pressure holding time, number of cycles and period in the washing oil tank 1 according to the actual formation pressure of the experimental sample.

[0060] In this invention, before starting the auxiliary pump 11, the vacuum pump 2 can be started first to evacuate the washing oil tank 1, which can accelerate the injection of washing oil solvent from the storage tank 6 into the washing oil tank 1.

[0061] In this invention, to ensure no leakage, the pressure rise and fall, pressure holding time, number of cycles, and period in the washing tank 1 need to be preset according to the actual formation pressure of the sample. The washing process employs a method of repeated pressurization and depressurization at room temperature. In this embodiment, 2-4 washing cycles are set. In each washing cycle: each pressurization is increased by 5-7 MPa, with a stabilization time of 10-30 minutes; each depressurization is decreased by 5-7 MPa, with a stabilization time of 10-30 minutes.

[0062] S6, set at least one oil washing cycle. Each oil washing cycle includes: using a gradient pressurization until the pressure in oil washing tank 1 reaches 2-5 MPa lower than the actual formation pressure of the sample, stabilizing for a certain period, and then gradually reducing the pressure. The oil washing action begins, specifically as follows:

[0063] Start the booster pump 10 to increase the pressure by 5-7 MPa each time, stabilize for 10-30 minutes, then increase the pressure again and stabilize for the same duration (5-7 MPa increase each time, 10-30 minutes stabilization). Repeat this process multiple times until the pressure in the washing tank 1 gradually increases to 2-5 MPa, which is lower than the formation pressure, and finally stabilizes for 2-3 hours. Then, use the booster pump 10 to depressurize and release the pressure in reverse stages, decreasing the pressure by 5-7 MPa each time, stabilizing for 10-20 minutes, until the pressure in the washing tank 1 drops to 0. One complete pressure increase and depressurization cycle in the washing tank 1 constitutes one washing cycle.

[0064] In this invention, different pressure increase and decrease programs are designed according to the actual formation pressure of the sample. By controlling the rise and fall of the pressure in the washing tank 1, the washing solvent is forced in or drawn out, and the resulting spit-and-puff action carries out the crude oil in the sample, thus achieving the purpose of washing the oil.

[0065] S7. Complete the set washing cycle of the washing action, and at the same time start the circulation pump 4 to circulate and disturb the washing solvent in the washing tank 1 to maintain the uniformity of the washing solvent in the washing tank 1.

[0066] S8, cyclic pressurization and depressurization, after at least one oil washing cycle (generally 2 to 4 cycles), bring the pressure of the oil washing tank 1 to 0; then open valve V11 on the third pipeline 15, and the oil washing solvent enters the third pipeline 15, which can be observed through the viewing window 8, from the oil washing tank 1, and then flows back to the solvent chamber 5. Observe the color of the oil washing solvent. If the oil washing solvent still has color, repeat steps S5 and S6 until the oil washing solvent is colorless as observed in the viewing window 8, then the experimental sample is considered to have been cleaned.

[0067] S9. After the sample is cleaned, reduce the pressure in the washing tank 1 to 0, start the air compressor 12, and return all the washing solvent in the washing tank 1 to the solvent chamber 5 through the third pipeline 15 with the viewing window 8.

[0068] S10, open the washing oil tank 1, take out the sample, let the washing oil solvent evaporate in the fume hood, and then hand the sample over to the next testing station.

[0069] S11, each time the washing solvent returns from the washing tank 1 to the solvent chamber 5, it is redistilled and purified in the solvent chamber 5 and then transferred to the storage tank 6 for use in the next sample cleaning.

[0070] In step S4, room temperature is maintained throughout the entire oil washing process of the sample, and the oil washing tank 1 is always kept at room temperature.

[0071] In step S8, after a cycle of cleaning is completed, when the cleaning solvent is returned to the solvent chamber 5, it can be observed through the viewing window 8 whether the cleaning solvent still has color, in order to determine whether the sample has been cleaned.

[0072] In step S9, the state of cleaning completion means that the pressure in the oil washing tank 1 is 0. The oil washing solvent can only be opened after it is returned to the solvent chamber 5, which helps to ensure personnel safety.

[0073] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0074] Finally, it should be noted that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A pressurized huff and puff oil washing unit suitable for use in compacted shale, characterized in that, Includes an oil washing tank, solvent chamber, circulation pump, and booster pump; The washing tank contains a sample of the oil to be washed; The first interface of the washing oil tank is located on the side and is connected to the first pipeline; The second interface of the oil washing tank is located at the top and is connected to the second pipeline; the third interface of the oil washing tank is located at the top and is connected to the third pipeline. The upper and lower parts of the washing tank are equipped with external circulation pipelines, and circulation pumps are installed on the circulation pipelines. A booster pump is installed at the bottom of the washing tank via a pipeline; The solvent chamber is connected to the first pipeline via a pipe.

2. The pressurized huff and puff oil washing unit suitable for use in compact shale according to claim 1, wherein, The pressurized huff and puff washing device suitable for dense mudstone and shale is also equipped with a storage tank. The solvent chamber is connected to the bottom of the storage tank through a pipeline, and the outlet of the storage tank is connected to the first pipeline.

3. The pressurized huff and puff oil washing unit suitable for use in a dense shale formation as claimed in claim 1, wherein, A secondary pump and a check valve are installed on the second pipeline.

4. The pressurized huff and puff oil washing unit suitable for use in a dense shale formation as claimed in claim 1, wherein, The pressurized huff and puff washing device suitable for dense mudstone and shale is also equipped with a condensation chamber. The cold source channel of the condensation chamber is connected to the cold source inlet pipe and the cold source outlet pipe, respectively. The heat source outlet of the condensation chamber is connected to the liquid storage tank and the solvent chamber through pipelines, respectively.

5. The pressurized huff and puff oil washing unit suitable for use in a dense shale formation as claimed in claim 2, wherein, The pressurized spit-and-swallow oil washing device is also equipped with a vacuum pump, which is connected to the second pipeline via a fifth pipeline.

6. The pressurized huff and puff oil washing unit suitable for use in a dense shale formation as claimed in claim 5, wherein, A buffer tank is also installed on the fifth pipeline.

7. The pressurized huff and puff oil washing unit suitable for use in a dense shale formation as defined in claim 3, wherein, The pressurized flushing oil washing device is also equipped with an air compressor, which is connected to the second pipeline through a fourth pipeline.

8. The pressurized huff and puff oil washing unit suitable for use in a dense shale formation as defined in claim 6, wherein, Two buffer tanks are installed sequentially on the fifth pipeline.

9. The pressurized huff and puff oil washing unit suitable for use in a dense shale formation as defined in claim 6, wherein, The cold source for the condenser is condensate.

10. The pressurized huff and puff oil washing unit suitable for use in compact shale as claimed in claim 6, wherein, A viewing window is provided on the third pipeline.

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