Temporary plugging agent evaluation device for cracks, holes and rock samples in various composite situations

Abstract

The present invention discloses a composite situation crack, hole, rock sample plugging device, including a pressure pump, an intermediate container and a simulated wellbore connected in sequence through pipelines, wherein the simulated wellbore is respectively provided with a rock plate clamp, a first core clamp, an API standard flow chamber, and a second core clamp; a simulated crack rock plate model is arranged in the rock plate clamp, a porous core model is arranged in the first core clamp, a rock plate is placed in the API standard flow chamber, and a target formation core is arranged in the second core clamp; by placing different types of rock samples in different clamps, the temporary plugging effect of a temporary plugging agent in formations with different structures can be effectively evaluated. The present invention evaluates the temporary plugging effect of a temporary plugging agent in rock samples with different structures under the same high temperature and high pressure conditions by setting a crack model, a porous core model, an API standard flow chamber rock plate, a real core, etc., so as to find a temporary plugging agent suitable for the target formation.

Description

Technical Field

[0001] The invention relates to the technical field of experimental devices, and in particular to a temporary plugging agent evaluation device for cracks, holes and rock samples in various composite situations. Background Art

[0002] Temporary plugging agent, also known as diverting agent, is a treatment agent widely used in oilfield production. It is a substance that temporarily reduces the permeability of the formation or temporarily plugs the high permeability oil layer. After being mixed with a water-soluble polymer and injected into the well, it can quickly form a thin and dense temporary plugging zone of the oil layer under the action of pressure difference, which can be unblocked by itself or manually after a certain period of time. In the development of unconventional oil and gas resources such as shale gas and tight oil, in order to effectively increase the complexity of hydraulic fractures, through the combination of temporary plugging agents of different particle sizes, a dense temporary plugging agent plugging zone can be generated near the wellbore fracture mouth or the far-field fracture end, forcing the fluid to turn, and generating new fractures or branch fractures, thereby achieving the purpose of increasing the complexity of fractures and increasing oil and gas production.

[0003] In the prior art, there are many temporary plugging fracturing simulation devices for studying the mechanism and effect of temporary plugging agents; for example, the publication number is CN108505967A, and the name is a temporary plugging experimental device for oil and gas well holes and cracks. The device can simulate the temporary plugging effect under various formation conditions by designing flow outlets and flat cracks of different numbers and sizes; the publication number is CN107202866A, and the name is a temporary plugging performance evaluation experimental device for temporary plugging agents and its working method and application. The invention can simulate various forms of cracks and complex fracture networks; however, the experimental environment of the above patents is carried out at normal temperature and pressure or low pressure, and only the temporary plugging situation in the crack is considered, and the diverse geological structures such as cracks and pores in the real reservoir are not considered. Therefore, the experimental results will be different from the real reservoir. Summary of the invention

[0004] In view of the above problems, the present invention provides a temporary plugging agent evaluation device for cracks, holes and rock samples in various composite situations. The temporary plugging agent is evaluated through cracks, porous and rock samples at the same time, and the effect of the temporary plugging agent can be more intuitively demonstrated under the contrast effect.

[0005] The present invention adopts the following technical solutions:

[0006] A temporary plugging agent evaluation device for cracks, holes and rock samples in various composite situations, including a pressure pump, an intermediate container and a simulated wellbore connected in sequence through pipelines, wherein the simulated wellbore is respectively provided with a rock plate holder, a first core holder, an API standard diversion chamber and a second core holder;

[0007] A simulated fractured rock plate model is arranged in the rock plate holder, a porous core model is arranged in the first core holder, a rock plate is placed in the API standard diversion chamber, and a target formation core is arranged in the second core holder; by placing different types of rock samples in different holders, the temporary plugging effect of the temporary plugging agent in formations with different structures can be effectively evaluated.

[0008] Preferably, the simulated crack rock slab model includes at least one simulated crack, and the width of the simulated crack is one or more of 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, and 6 mm, thereby simulating cracks of different widths.

[0009] Preferably, the porous core model includes a core with a circular hole on the radial end face or a core with an irregular hole on the radial end face, so as to simulate the structure of a real formation rock sample;

[0010] The diameter of the circular hole is one or more of 8 mm, 9 mm, 10 mm, 11 mm, and 12 mm, and the diameter of the irregular-shaped hole is one or more of 2 mm, 3 mm, 4 mm, and 5 mm.

[0011] Preferably, the API standard flow diversion chamber (the seam width between the inner rock plates is set to one of 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, and 10mm.

[0012] Preferably, the outlet ends of the rock plate clamp, the first core clamp, the API standard flow guide chamber, and the second core clamp are all provided with a first pressure sensor for measuring the pressure at the outlet ends.

[0013] Preferably, a temperature sensor is provided on the simulated wellbore for measuring the temperature inside the simulated wellbore, and an electric heating tube is provided at the lower end of the simulated wellbore for heating the temporary plugging agent in the simulated wellbore, which can more realistically simulate the working environment of the temporary plugging agent under formation conditions.

[0014] Preferably, hollow cores are provided in the pipes connecting the rock plate holder, the first core holder, the API standard flow diversion chamber, the second core holder and the simulated wellbore, and the hollow cores are used to simulate the flow path of the temporary plugging agent in the formation.

[0015] The beneficial effects of the present invention are:

[0016] 1. The present invention sets a fracture model, a porous core model, an API standard diversion chamber rock plate, a real core, etc., and evaluates the temporary plugging effect of the temporary plugging agent in rock samples with different structures under the same high temperature and high pressure conditions, so as to find a temporary plugging agent suitable for the target formation.

[0017] 2. The present invention can compare multiple groups of rock sample models simultaneously during the experiment, and the experimental results are more vivid and intuitive. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present invention, but are not intended to limit the present invention.

[0019] Figure 1 It is a structural schematic diagram of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the simulated wellbore and rock plate clamp, the first core clamp, the API standard flow chamber, and the second core clamp of the present invention;

[0021] Figure 3 It is a schematic diagram of the cross-sectional structure of the simulated wellbore of the present invention;

[0022] Figure 4 It is a schematic structural diagram of a porous core model (with a circular hole on the radial end surface) of the present invention;

[0023] Figure 5 It is a schematic structural diagram of the porous core model of the present invention (the radial end surface is irregular holes);

[0024] Figure 6 It is a schematic diagram of the structure of the hollow core in the pipeline of the present invention.

[0025] As shown in the figure

[0026] 1—simulated wellbore, 2—rock plate holder, 3—first core holder, 4—API standard flow chamber, 5—second core holder, 6—temperature sensor, 7—first pressure sensor, 8—electric heating pipe, 9—boosting pump, 10—intermediate container, 11—second pressure sensor, 12—pipeline; DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure shall have the usual meanings understood by persons with ordinary skills in the field to which the present disclosure belongs. The words "include" or "comprise" and the like used in the present disclosure mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0029] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0030] like Figures 1 to 6 As shown, a temporary plugging agent evaluation device for cracks, holes and rock samples in various composite situations includes a simulated wellbore 1 made of Hastelloy, an intermediate container 9 and a pressure pump 10. The outlet end of the intermediate container 9 is connected to the inlet end of the simulated wellbore 1 through a pipeline, and a second pressure sensor is provided on the connected pipeline. The pressure pump 10 is connected to the inlet end of the intermediate container 9 through a pipeline. The pressure pump 10 adopts a pressure multiplier or a manual pump to make the pressure in the simulated wellbore 1 reach 40MP-70MP, which can better simulate the high-pressure environment of the temporary plugging agent in the real formation and improve the evaluation effect of the temporary plugging agent.

[0031] The simulated wellbore 1 is surrounded by a rock plate holder 2, a first core holder 3, an API standard flow chamber 4, and a second core holder 5.

[0032] The rock plate clamp 2, the first core clamp 3, the API standard diversion chamber 4, and the second core clamp 5 are all connected to the simulated wellbore 1 through a pipeline 12. A hollow cylindrical core is placed in the pipeline 12. The hollow core is used to simulate the flow path of the temporary plugging agent in the formation, which more realistically reflects the formation structure.

[0033] A simulated fractured rock plate model is placed in the rock plate holder 2, a porous core model is set in the first core holder 3, a rock plate is placed in the API standard flow chamber 4, and a core after the target formation is fractured is placed in the second core holder 5;

[0034] The simulated crack rock slab model uses the rock slab of the target stratum or artificial rock slab to simulate at least one simulated crack, and the width of the simulated crack is one or more of 1mm, 2mm, 3mm, 4mm, 5mm, and 6mm, thereby simulating cracks of different widths.

[0035] The porous core model includes a core with a circular hole on the radial end face or a core with an irregular hole on the radial end face, and the above two types of cores are both from the target formation or artificial cores, so as to simulate the real formation rock sample structure;

[0036] The diameter of the circular hole is one or more of 8 mm, 9 mm, 10 mm, 11 mm, and 12 mm, and the diameter of the irregular-shaped hole is one or more of 2 mm, 3 mm, 4 mm, and 5 mm.

[0037] The seam width between the rock plates in the API standard diversion chamber 4 is set to one of 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, and 10mm. The rock plates come from the target formation or use artificial rock plates, which can effectively simulate the structure of the rock sample at the perforation location.

[0038] The present invention can effectively evaluate the temporary plugging effect of the temporary plugging agent in strata with different structures by placing different types of rock samples in different holders, which is different from the prior art which only evaluates the temporary plugging condition of the temporary plugging agent in the crack.

[0039] The outlet ends of the rock plate clamp 2, the first core clamp 3, the API standard flow chamber 4, and the second core clamp 5 are all provided with a first pressure sensor 7 for measuring the pressure at the outlet end; the temporary plugging condition of the temporary plugging agent is evaluated by observing and calculating the pressure difference between the first pressure sensor 7 and the second pressure sensor 11.

[0040] The simulated wellbore 1 is provided with a temperature sensor 6 for measuring the temperature inside the simulated wellbore 1. The lower end of the simulated wellbore 1 is provided with an electric heating tube 8 for heating the temporary plugging agent in the simulated wellbore 1 so that its temperature ranges from room temperature to 150°, which can more realistically simulate the working environment of the temporary plugging agent under high temperature conditions in the formation.

[0041] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A temporary plugging agent evaluation device for cracks, holes and rock samples in various composite situations, characterized by: It comprises a pressure pump (10), an intermediate container (9) and a simulated wellbore (1) which are connected in sequence through pipelines, wherein a rock plate holder (2), a first core holder (3), an API standard flow diversion chamber (4) and a second core holder (5) are respectively provided around the simulated wellbore (1); A simulated fractured rock plate model is arranged in the rock plate holder (2), a porous core model is arranged in the first core holder (3), a rock plate is placed in the API standard flow diversion chamber (4), and a target formation core is arranged in the second core holder (5); The simulated wellbore (1) is provided with a temperature sensor (6) for measuring the temperature inside the simulated wellbore (1); the lower end of the simulated wellbore (1) is provided with an electric heating pipe (8); A hollow core is provided in the pipe (12) connecting the rock plate holder (2), the first core holder (3), the API standard flow diversion chamber (4), the second core holder (5) and the simulated wellbore (1).

2. The temporary plugging agent evaluation device for multiple composite situations of cracks, holes and rock samples according to claim 1 is characterized in that: The simulated crack rock plate model includes at least one simulated crack, and the width of the simulated crack is one or more of 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, and 6 mm.

3. The temporary plugging agent evaluation device for multiple composite situations of cracks, holes and rock samples according to claim 1 is characterized in that: The porous core model includes a core with a circular hole on the radial end surface or a core with an irregular hole on the radial end surface; The diameter of the circular hole is one or more of 8 mm, 9 mm, 10 mm, 11 mm, and 12 mm, and the diameter of the irregular-shaped hole is one or more of 2 mm, 3 mm, 4 mm, and 5 mm.

4. The temporary plugging agent evaluation device for multiple composite fractures, holes and rock samples according to claim 1, characterized in that: The seam width between the rock plates in the API standard diversion chamber (4) is set to one of 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, and 10 mm.

5. The temporary plugging agent evaluation device for multiple composite fractures, holes and rock samples according to any one of claims 1 to 4, characterized in that: The rock plate holder (2), the first core holder (3), the API standard flow guide chamber (4), and the outlet ends of the second core holder (5) are all provided with a first pressure sensor (7).

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