Device and method for evaluating plugging characteristics of temporary plugging material

Abstract

The invention provides a device and method for evaluating the plugging characteristic of a temporary plugging material, the device comprises a liquid preparation mechanism, a pump injection mechanism and a ball injection mechanism which are sequentially connected through a pipeline, a shaft simulation mechanism and a recovery mechanism, and the liquid preparation mechanism comprises a liquid storage tank; the pump injection mechanism comprises a circulating pump and can pump fluid into the simulation shaft mechanism; the ball throwing mechanism comprises a ball throwing opening and can throw temporary plugging materials. The simulation shaft mechanism comprises an organic glass pipeline, the hole drift angle is 0-90 degrees, and a plurality of clusters of simulation shot holes are formed in the organic glass pipeline; the recovery mechanism comprises a first recovery unit connected with the multiple clusters of simulated shot holes and a second recovery unit connected with one end of the organic glass pipeline. The method is realized through the device, and comprises the following steps: evaluating the migration of the temporary plugging material in the wellbore simulation mechanism, and / or evaluating the plugging performance of the temporary plugging material on the multi-cluster perforation. The method can quantitatively evaluate the plugging effect, and is high in feasibility.

Description

Technical Field

[0001] This invention relates to the field of oil and gas well fracturing and stimulation technology, specifically to an apparatus and a method for evaluating the sealing characteristics of temporary plugging materials. Background Technology

[0002] Shale gas has become a major resource for oil and gas development both domestically and internationally. Long-section multi-cluster fracturing and temporary plugging is one of the technologies used in unconventional oil and gas resource development. The core of this technology is to segment horizontal wells, with each segment containing multiple perforation clusters. By creating multiple perforations within each segment, several hydraulic fractures can be formed simultaneously in a single pump injection, effectively reducing construction costs. In the multi-cluster fracturing perforation mode, some perforations have poor fluid inflow, making fractures difficult to open. By using temporary plugging technology to seal the fracture opening or interior, the fracturing fluid is redirected, improving the fracture opening efficiency of each perforation cluster and effectively extending the fractures within each cluster. This ultimately aims to increase single-well production and reservoir recovery.

[0003] Temporary plugging materials can be categorized into spherical, granular, fiber, and liquid gel types. Spherical and granular types are the two most commonly used types for fracturing temporary plugging. Spherical plugging agents are mainly used for sealing blast holes, while granular types are used for temporary plugging within fractures. Domestic and international scholars have conducted laboratory experiments to study the fracture sealing effects under different plugging agent formulations, fracture widths, injection rates, and other factors. However, the devices used cannot simultaneously meet the requirements of visualizing and dynamically plugging blast holes, and their pressure-bearing capacity is poor, differing significantly from actual formation conditions and failing to accurately reproduce the on-site construction conditions. Furthermore, a systematic evaluation method is lacking, making it impossible to select appropriate temporary plugging agents. Therefore, this application provides a device and method that can effectively meet actual working conditions, reproduce on-site construction conditions, and observe the process of temporary plugging materials sealing blast holes, thus evaluating the plugging characteristics of temporary plugging materials. This is of great significance.

[0004] Chinese invention patent application number "CN202211376017.8" entitled "Device and Experimental Method for Evaluating the Migration and Plugging Performance of Temporary Plugging Fracturing Plugging Materials" discloses a device and experimental method for evaluating the migration and plugging performance of temporary plugging fracturing plugging materials, belonging to the field of oil and gas field development technology. The device includes a pumping module, a simulated wellbore module, a simulated perforation module, and a simulated fracture module. The pumping module is connected to the simulated wellbore module, and the outlet of the simulated wellbore module is connected to the simulated fracture module. The pumping module is used to pump working fluid carrying the temporary plugging agent / ball into the simulated wellbore module and the simulated fracture module. The simulated wellbore module is used to simulate vertical or horizontal wellbores. The simulated perforation module is installed on the simulated wellbore module and is used to simulate underground directional perforation. Both the inlet of the simulated wellbore module and the outlet of the simulated perforation module are equipped with flow metering modules and flow control valves. This invention solves the problem of unclear "migration-plugging" mechanisms of temporary plugging materials and the lack of suitable physical simulation experimental devices. However, this application differs from its apparatus and method. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to solve one or more problems existing in the prior art. For example, one objective of the present invention is to provide a device for evaluating the sealing characteristics of temporary plugging materials that can more realistically reproduce on-site construction conditions and observe the process of temporary plugging materials sealing blast holes. Another objective of the present invention is to provide a method for evaluating the sealing characteristics of temporary plugging agents, which involves testing the sealing performance of temporary plugging materials in wellbore through indoor experiments and using quantitative evaluation methods for systematic evaluation, effectively improving the accuracy of indoor evaluation.

[0006] To achieve the above objectives, the present invention provides an apparatus for evaluating the plugging characteristics of temporary plugging materials. The apparatus may include: a liquid dispensing mechanism, a pumping mechanism, and a ball-throwing mechanism connected sequentially by pipelines; a simulated wellbore mechanism; and a recovery mechanism. The liquid dispensing mechanism includes a storage tank with an internal stirring paddle and a liquid inlet at the top. The pumping mechanism includes a circulating pump capable of pumping fluid from the liquid dispensing mechanism into the simulated wellbore mechanism. The ball-throwing mechanism includes a ball-throwing port capable of dispensing the temporary plugging material. The simulated wellbore mechanism includes an acrylic glass pipeline with a well inclination angle of 0–90°, and multiple clusters of simulated boreholes are provided on the acrylic glass pipeline. The recovery mechanism includes a first recovery unit connected to the multiple clusters of simulated boreholes and a second recovery unit connected to one end of the acrylic glass pipeline.

[0007] According to one or more exemplary embodiments of one aspect of the present invention, the device may further include: a safety valve and a pressure gauge disposed on a pipeline between the ball-throwing mechanism and the simulated well mechanism, wherein the safety valve is capable of releasing pressure and triggering an alarm; and the pressure gauge is capable of measuring the pressure in the pipeline.

[0008] Another aspect of the present invention provides a method for evaluating the plugging characteristics of a temporary plugging material. The method can be implemented by using the apparatus for evaluating the plugging characteristics of a temporary plugging material as described above. The method may include: evaluating the migration of the temporary plugging material in a simulated wellbore structure, and / or evaluating the plugging performance of the temporary plugging material for multi-cluster perforations.

[0009] According to one or more exemplary embodiments of another aspect of the present invention, the evaluation of the migration of temporary plugging material in a simulated wellbore mechanism may include the following steps: determining indoor experimental parameters based on actual construction parameters at the target block site, selecting a carrier fluid and a temporary plugging material; pumping the uniformly mixed carrier fluid in the storage tank into the simulated wellbore mechanism through the pumping mechanism; releasing the temporary plugging material through the ball-throwing mechanism, with the carrier fluid carrying the temporary plugging material to migrate in the simulated wellbore mechanism, adjusting the parameters to obtain the migration distance of different temporary plugging materials.

[0010] According to one or more exemplary embodiments of another aspect of the present invention, evaluating the sealing performance of the temporary plugging material for multiple perforations may include the following steps: determining indoor experimental parameters based on actual construction parameters at the target block site, selecting a carrier fluid and a temporary plugging material; pumping the uniformly mixed carrier fluid in the storage tank into the simulated wellbore mechanism through the pumping mechanism; releasing the temporary plugging material through the ball-throwing mechanism; counting the number of simulated blast holes sealed, counting the mass of the temporary plugging material inside and out of the simulated blast holes, and obtaining the simulated blast hole sealing ratio and the temporary plugging material utilization rate.

[0011] According to one or more exemplary embodiments of another aspect of the present invention, the carrying fluid may include fracturing fluid with an apparent viscosity of 3 to 10 mPa·s; the temporary plugging material may include at least one of temporary plugging particles with a diameter of 1 to 3 mm, temporary plugging balls with a diameter of 5 to 30 mm, and knots.

[0012] According to one or more exemplary embodiments of another aspect of the present invention, the formula for determining the indoor experimental parameters may include the following formulas 1 and 2:

[0013] Formula 1:

[0014] Among them, Q 单孔 For single-hole displacement, m 3 / min; Q 总 The total discharge volume during construction is in m. 3 / min; n is the number of blast holes during temporary closure construction;

[0015] Formula 2:

[0016] Where Re is the Reynolds number, which is dimensionless; ρ fluid Fluid density, kg / m³ 3;v fluid d represents the fluid velocity, in m / s; pipe η is the inner diameter of the pipe, in meters; η is the fluid viscosity, in Pa·s; Q 总 The total discharge volume during construction is in m. 3 / min.

[0017] According to one or more exemplary embodiments of another aspect of the present invention, the formula for determining the indoor experimental parameters may further include the following formulas 3 and 4:

[0018] Equation 3: Re 现场 =Re 室内 ;

[0019] Among them, Re 现场 Re is the actual Reynolds number of the target block, dimensionless; 室内 is the Reynolds number during indoor testing, which is dimensionless;

[0020] Equation 4: Q 泵 =n 室内 Q 单孔 ;

[0021] Among them, Q 泵 The pump displacement during indoor experiments, in m 3 / min;n 室内 The number of boreholes used in indoor testing.

[0022] According to one or more exemplary embodiments of another aspect of the present invention, the simulated borehole sealing ratio can be determined by the following formula 5:

[0023] Formula 5:

[0024] Where, θ 炮眼 The percentage of blast hole sealing is %. 封堵 n represents the number of blast holes sealed with temporary plugging agent. 室内 The number of boreholes used in indoor testing.

[0025] According to one or more exemplary embodiments of another aspect of the present invention, the utilization rate of the temporary plugging material can be determined by the following formula 6:

[0026] Formula 6:

[0027] Where, η 暂堵材料 The utilization rate of temporary plugging materials is %, m. 封堵 The amount of temporary plugging material used to seal the blast hole, in g; m 总 The total amount of temporary plugging material injected is in grams (g).

[0028] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0029] (1) The device for evaluating the sealing characteristics of temporary plugging materials provided by the present invention can more closely approximate the actual on-site construction conditions, truly simulate on-site construction, and reduce the errors caused by mathematical calculations and physical factors in the test process.

[0030] (2) The method for evaluating the plugging characteristics of temporary plugging materials provided by the present invention can quantitatively evaluate the plugging effect of temporary plugging materials by calculating the plugging ratio of blast holes and the utilization rate of temporary plugging materials, effectively guiding the selection of temporary plugging materials and the optimization design of fracturing construction, and has high feasibility.

[0031] (3) The method for evaluating the plugging characteristics of temporary plugging materials provided by the present invention has a simple calculation process and is safe and effective to operate. Attached Figure Description

[0032] The above and other objects and / or features of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0033] Figure 1 A schematic diagram of a device for evaluating the plugging characteristics of temporary plugging materials in an exemplary embodiment of the present invention is shown;

[0034] Figure 2 A partial structural schematic diagram of the apparatus for evaluating the plugging characteristics of temporary plugging materials in Example 1 of the present invention is shown.

[0035] Explanation of reference numerals in the attached figures:

[0036] 11-Storage tank, 12-Inlet, 2-Pumping mechanism, 3-Ball throwing mechanism, 41-Acrylic glass pipeline, 42-Simulated blast hole, 43-Horizontal wellbore, 51-First recovery unit, 52-Second recovery unit, 6-Safety valve, 7-Pressure gauge. Detailed Implementation

[0037] The apparatus and method for evaluating the plugging properties of temporary plugging materials of the present invention will be described in detail below with reference to the accompanying drawings and exemplary embodiments.

[0038] In the description of this application, it should be understood that the terms "upper," "left," "right," "horizontal," "top," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing 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, and therefore should not be construed as a limitation of this application. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0039] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0040] Exemplary Example 1

[0041] Figure 1 A schematic diagram of an apparatus for evaluating the plugging characteristics of temporary plugging materials is shown in an exemplary embodiment of the present invention.

[0042] This exemplary embodiment provides an apparatus for evaluating the plugging characteristics of temporary plugging materials.

[0043] like Figure 1 As shown, the device for evaluating the plugging characteristics of temporary plugging materials may include: a liquid dispensing mechanism, a pumping mechanism 2 and a ball dropping mechanism 3 connected in sequence by pipelines, as well as a simulated wellbore mechanism and a recovery mechanism.

[0044] The liquid preparation mechanism includes a storage tank 11, which contains a stirring paddle and an inlet 12 at the top. The pumping mechanism 2 includes a circulation pump capable of pumping the fluid from the liquid preparation mechanism into the simulated wellbore mechanism. Here, the circulation pump can be a magnetic pump with a displacement of 70 m³ / s. 3 / h, with a pressure resistance of 2MPa. The ball-throwing mechanism 3 includes a ball-throwing port for dispensing temporary plugging material. The simulated wellbore mechanism includes an acrylic glass pipe 41 with a well inclination angle of 0–90°, for example, 23°, 33°, 53°, 66°, 73°, or 83°. Multiple clusters of simulated boreholes 42 are provided on the acrylic glass pipe 41. Here, the acrylic glass pipe 41 can be used to visually observe the movement of the temporary plugging material within the pipe and to evaluate the temporary plugging characteristics. The length of the acrylic glass pipe 41 can be 4.5m, the outer diameter can be 120mm, and the inner diameter can be 80mm. The simulated boreholes 42 are used to simulate the on-site perforation state. Here, multiple clusters of simulated boreholes 42 are evenly distributed on the acrylic glass pipe 41, with 15 holes in 3 clusters, each cluster containing 5 holes, and the inner diameter of the holes is 10mm. The recovery mechanism includes a first recovery unit 51 connected to multiple clusters of simulated boreholes 42 and a second recovery unit 52 connected to one end of an plexiglass conduit 41. Here, the first recovery unit 51 can be a liquid receiver for receiving the temporary plugging working fluid flowing out of the simulated boreholes 42, and the second recovery unit 52 is used to recover the temporary plugging fluid after the experiment.

[0045] In this exemplary embodiment, the apparatus for evaluating the sealing characteristics of the temporary plugging material may further include: a safety valve 6 and a pressure gauge 7 disposed on the pipeline between the ball-throwing mechanism 3 and the simulated wellbore mechanism, wherein the safety valve 6 is capable of releasing pressure and alarming, and the pressure gauge 7 is capable of measuring the pressure in the pipeline.

[0046] Exemplary Example 2

[0047] This exemplary embodiment provides a method for evaluating the plugging characteristics of temporary plugging materials, which can be implemented using an apparatus for evaluating the plugging characteristics of temporary plugging materials as described in Exemplary Embodiment 1.

[0048] In this exemplary embodiment, the method for evaluating the plugging characteristics of a temporary plugging material may include: evaluating the migration of the temporary plugging material in a simulated wellbore structure, and / or evaluating the plugging performance of the temporary plugging material for multiple perforations.

[0049] In this exemplary embodiment, evaluating the migration of temporary plugging material in a simulated wellbore structure may include the following steps: determining indoor experimental parameters based on actual construction parameters at the target block site, selecting carrier fluid and temporary plugging material; pumping the uniformly mixed carrier fluid from the storage tank into the simulated wellbore structure via a pumping mechanism; releasing the temporary plugging material via a ball-throwing mechanism, with the carrier fluid carrying the temporary plugging material to migrate within the simulated wellbore structure, adjusting parameters to obtain the migration distance of different temporary plugging materials.

[0050] In this exemplary embodiment, evaluating the sealing performance of temporary plugging material for multi-cluster perforations may include the following steps: determining indoor experimental parameters based on actual construction parameters at the target block site, and selecting carrier fluid and temporary plugging material; pumping the uniformly mixed carrier fluid from the storage tank into the simulated wellbore mechanism via a pumping mechanism; releasing the temporary plugging material via a ball-throwing mechanism; counting the number of simulated blast holes sealed, and counting the mass of temporary plugging material flowing into and out of the simulated blast holes to obtain the simulated blast hole sealing ratio and temporary plugging material utilization rate.

[0051] In this exemplary embodiment, the carrier fluid may include fracturing fluid with an apparent viscosity of 3 to 10 mPa·s, and the temporary plugging material may include at least one of temporary plugging particles with a diameter of 1 to 3 mm, temporary plugging balls with a diameter of 5 to 30 mm, and knots.

[0052] In this exemplary embodiment, the formulas for determining the indoor experimental parameters may include the following Equations 1 and 2:

[0053] Formula 1:

[0054] Among them, Q 单孔 For single-hole displacement, m 3 / min; Q 总 The total discharge volume during construction is in m. 3 / min; n is the number of blast holes during temporary closure construction;

[0055] Formula 2:

[0056] Where Re is the Reynolds number, which is dimensionless; ρ fluid Fluid density, kg / m³ 3 ;v fluiid d represents the fluid velocity, in m / s; pipe Pipe inner diameter, m; μ, fluid viscosity, Pa·s; Q 总 The total discharge volume during construction is in m. 3 / min.

[0057] In this exemplary embodiment, the formula for determining the indoor experimental parameters may further include the following formulas 3 and 4:

[0058] Equation 3: Re 现场 =Re 室内 ;

[0059] Among them, Re 现场 Re is the actual Reynolds number of the target block, dimensionless; 室内 is the Reynolds number during indoor testing, which is dimensionless;

[0060] Equation 4: Q 泵 =n 室内 Q 单孔 ;

[0061] Among them, Q 泵 The pump displacement during indoor experiments, in m 3 / min;n 室内 The number of boreholes used in indoor testing.

[0062] In this exemplary embodiment, the simulated borehole sealing ratio can be determined by the following formula 5:

[0063] Formula 5:

[0064] Where, η 炮眼 The percentage of blast hole sealing is %. 封堵 n represents the number of blast holes sealed with temporary plugging agent. 室内 The number of boreholes used in indoor testing.

[0065] In this exemplary embodiment, the utilization rate of the temporary plugging material can be determined by the following formula 6:

[0066] Formula 6:

[0067] Where, η 暂堵材料 The utilization rate of temporary plugging materials is %, m. 封堵 The amount of temporary plugging material used to seal the blast hole, in g; m 总 The total amount of temporary plugging material injected is in grams (g).

[0068] To better understand the above exemplary embodiments 1-2, we will provide a more detailed explanation below with reference to specific examples.

[0069] Example 1

[0070] In this example, when the well inclination angle of the device used to evaluate the plugging characteristics of the temporary plugging material is 90°, i.e., when the plexiglass tubing in the simulated wellbore structure is a horizontal wellbore, such as Figure 2 As shown, two clusters of blast holes are installed on the horizontal shaft. Part A is the inlet end, which is the first cluster, including 3 blast holes, labeled P1, P2 and P3 from left to right in the horizontal direction. Part B is the outlet end, which is the second cluster, including 3 blast holes, labeled P4, P5 and P6 from left to right in the horizontal direction. The angle between blast holes P1 and P4 is 60°, the angle between blast holes P2 and P5 is 0°, and the angle between blast holes P3 and P6 is 75°.

[0071] In this example, using Figure 2The apparatus shown was used to investigate the settling and migration patterns of temporary plugging materials in a horizontal wellbore, i.e., to evaluate the migration of temporary plugging materials in a simulated wellbore structure. The number of temporary plugging materials was set to be greater than the number of orifices. The selected temporary plugging materials included temporary plugging balls with diameters of 7–8 mm, 10–12 mm, and 15 mm, temporary plugging particles with diameters of 1–3 mm, and rope knots with diameters of 15 mm. The carrying fluid was fracturing fluid with an apparent viscosity of 7 mPa·s.

[0072] Specifically, this may include the following steps:

[0073] Configuration 1m 2 The fracturing fluid is placed in storage tank 11.

[0074] Turn on the circulation pump to pump the carrier liquid into the entire device, and adjust the discharge rate to 0.6 m³. 3 / min, where the parameter can be determined by Equations 1, 2, 3 and 4 above.

[0075] Repeat 1-2 cycles.

[0076] 50g of temporary plugging particles with a diameter of 1-3mm, 12 temporary plugging balls with a diameter of 7-8mm, 12 temporary plugging balls with a diameter of 10-12mm, 12 temporary plugging balls with a diameter of 15mm, and 12 rope knots with a diameter of 15mm are respectively put into the ball-throwing mechanism through the ball-throwing port, and then into the simulated well shaft mechanism.

[0077] The carrying fluid carries the temporary plugging material in the horizontal wellbore 43 and circulates it back to the storage tank 11. The migration trajectory of the temporary plugging material in the horizontal wellbore is simulated, and the migration distance of different temporary plugging materials is obtained. The results are shown in Table 1 below.

[0078] Table 1. Transport distance of different temporary plugging materials

[0079]

[0080] As shown in Table 1, the type and size of the temporary plugging agent have a significant impact on the migration distance. For knots and balls of the same size, the knots migrate farther than the balls. For the same type of temporary plugging material, smaller sizes migrate farther than larger sizes.

[0081] Example 2

[0082] In this example, using Figure 1 The apparatus shown explores the plugging performance of temporary plugging materials on multi-cluster perforations, i.e., evaluates the plugging performance of temporary plugging materials on multi-cluster perforations. The number of temporary plugging materials is greater than the number of perforations. The selected temporary plugging materials include temporary plugging balls with diameters of 7-8 mm, 10-12 mm, and 15 mm, temporary plugging particles with diameters of 1-3 mm, and rope knots with diameters of 15 mm. The carrying fluid is fracturing fluid with an apparent viscosity of 7 mPa·s.

[0083] Specifically, this may include the following steps:

[0084] Based on the actual construction parameters of the target block, the indoor experimental parameters are determined. These parameters can be determined using Equations 1, 2, 3, and 4 above.

[0085] Configuration 1m 2 The fracturing fluid is placed in storage tank 11.

[0086] Connect the pumping mechanism 2, the storage tank 11, and the simulated well mechanism with pipelines, and turn on the circulation pump to pump fluid into the pipeline, filling the entire device.

[0087] 50g of temporary blocking particles with a diameter of 1-3mm, 12 temporary blocking balls with a diameter of 7-8mm, 12 temporary blocking balls with a diameter of 10-12mm, 12 temporary blocking balls with a diameter of 15mm, and 12 rope knots with a diameter of 15mm are respectively introduced into the ball-throwing mechanism 3 through the ball-throwing port, and then into the plexiglass tube 41.

[0088] Place the other end of the pipeline connecting to the outlet of simulated blast hole 42 into a container placed on an electronic scale and count the liquid output.

[0089] The number of simulated blast hole 42 plugs was counted. The temporary plugging material concentration was 1%, and the discharge rate was 0.5 m³. 3 / min.

[0090] After the pump was stopped, the mass of the temporary plugging material inside the simulated blast hole 42 was statistically analyzed.

[0091] The simulated borehole plugging ratio (i.e., borehole plugging ratio) and temporary plugging material utilization rate were determined by Equations 5 and 6 above, and the results are shown in Table 2 below.

[0092] Table 2. Burr hole plugging ratio and temporary plugging material utilization rate with different temporary plugging materials

[0093]

[0094] As shown in Table 2, the plugging characteristics of temporary plugging agents can be evaluated from multiple aspects such as the plugging ratio of blast holes and the utilization rate of temporary plugging materials. Temporary plugging particles and knots have better plugging characteristics.

[0095] In summary, this invention addresses the shortcomings of existing technologies in meeting actual working conditions by providing a device and method for evaluating the sealing characteristics of temporary plugging materials. Through indoor experiments testing the sealing performance of temporary plugging materials in the wellbore, it recreates on-site construction conditions and observes the process of the temporary plugging material sealing perforations, thus enabling better evaluation and selection of the sealing performance of temporary plugging materials. The device and method provided by this invention can more realistically recreate on-site construction conditions, using quantitative evaluation methods for systematic evaluation, effectively improving the accuracy of indoor evaluations. This invention can explore both the settlement and migration patterns of temporary plugging materials in horizontal wellbores during fracturing and the sealing performance of temporary plugging materials for multi-cluster perforations, better evaluating the sealing characteristics of temporary plugging materials and facilitating the selection of optimal temporary plugging materials.

[0096] Although the invention has been described above in conjunction with exemplary embodiments, those skilled in the art will understand that various modifications and changes can be made to the exemplary embodiments of the invention without departing from the spirit and scope defined by the claims.

Claims

1. An apparatus for evaluating the plugging characteristics of a bridging material, comprising: The device comprises a liquid preparation mechanism, a pump injection mechanism and a ball injection mechanism connected in sequence through pipelines, and a simulated wellbore mechanism and a recovery mechanism, wherein, The liquid preparation mechanism comprises a liquid storage tank, which is internally provided with a stirring paddle and externally provided with a liquid inlet; The pump injection mechanism comprises a circulating pump, which can pump the fluid in the liquid preparation mechanism into the simulated wellbore mechanism; The ball injection mechanism comprises a ball injection port, which can inject the temporary plugging material; The simulated wellbore mechanism comprises a plexiglass pipeline, which has an inclination angle of 0-90°, and is provided with multiple simulated perforation holes; The recovery mechanism comprises a first recovery unit connected with the multiple simulated perforation holes and a second recovery unit connected with one end of the plexiglass pipeline.

2. The apparatus of claim 1, wherein, The device further comprises a safety valve and a pressure gauge arranged on the pipeline between the ball injection mechanism and the simulated wellbore mechanism, wherein, The safety valve can relieve pressure and alarm; The pressure gauge can measure the pressure in the pipeline.

3. A method of evaluating the plugging properties of a bridging material, characterized by, The method is realized by using the device for evaluating the plugging characteristics of the temporary plugging material according to any one of claims 1-2, and comprises evaluating the migration of the temporary plugging material in the simulated wellbore mechanism and / or evaluating the plugging performance of the temporary plugging material to the multiple perforations.

4. The method of evaluating the plugging properties of a bridging material of claim 3, wherein, The evaluation of the migration of the temporary plugging material in the simulated wellbore mechanism comprises the following steps: Based on the actual construction parameters of the target block, the indoor experimental parameters are determined, and the carrying fluid and the temporary plugging material are selected; The uniformly mixed carrying fluid in the liquid storage tank is pumped into the simulated wellbore mechanism by the pump injection mechanism; The temporary plugging material is injected by the ball injection mechanism, the carrying fluid carries the temporary plugging material to migrate in the simulated wellbore mechanism, the parameters are adjusted, and the migration distances of different temporary plugging materials are obtained.

5. The method of evaluating the plugging properties of a bridging material of claim 3, wherein, The evaluation of the plugging performance of the temporary plugging material to the multiple perforations comprises the following steps: Based on the actual construction parameters of the target block, the indoor experimental parameters are determined, and the carrying fluid and the temporary plugging material are selected; The uniformly mixed carrying fluid in the liquid storage tank is pumped into the simulated wellbore mechanism by the pump injection mechanism; The temporary plugging material is injected by the ball injection mechanism; The number of plugged simulated perforation holes is counted, the mass of the temporary plugging material in and out of the simulated perforation holes is counted, and the simulated perforation hole plugging ratio and the temporary plugging material usage rate are obtained.

6. The method of evaluating the plugging properties of a bridging material according to claim 4 or 5, wherein, The carrying fluid comprises a fracturing fluid with an apparent viscosity of 3-10 mPa·s; and the temporary plugging material comprises at least one of temporary plugging particles with a diameter of 1-3 mm, temporary plugging balls with a diameter of 5-30 mm and a knot.

7. The method of evaluating the plugging properties of a bridging material according to claim 4 or 5, wherein, The formula for determining the indoor experimental parameters comprises the following formula 1 and formula 2: Formula 1: wherein Q 单孔 is the single-hole discharge of the blast hole, m 3 / min; Q 总 is the total discharge of the construction, m 3 / min; and n is the number of blast holes during temporary plugging construction, pieces. Formula 2: where Re is the Reynolds number, dimensionless; p fluid is the fluid density, kg / m 3 ; v fluid is the fluid flow rate, m / s; d pipe is the pipe inner diameter, m; and p is the fluid viscosity, Pa-s; Q 总 is the total construction discharge, m 3 / min.

8. The method of evaluating the plugging properties of a bridging material according to claim 4 or 5, wherein, The formula for determining the indoor experimental parameters further comprises the following formula 3 and formula 4: Formula 3: Re 现场 = Re 室内 ; where Re 现场 is the Reynolds number for the target block in the field, dimensionless; Re 室内 is the Reynolds number for the indoor test, dimensionless; Formula 4: Q 泵 = n 室内 Q 单孔 ; wherein Q 泵 is the pump displacement, m 3 / min; n 室内 is the number of holes, pieces.

9. The method of evaluating the plugging properties of a bridging material of claim 5, wherein, The simulated perforation hole plugging ratio is determined by the following formula 5: Formula 5: wherein η 炮眼 is the percentage of the gun hole plugging ratio; n 封堵 is the number of gun holes plugged by the temporary plugging agent; n 室内 is the number of gun holes in the laboratory test.

10. The method of evaluating the plugging properties of a bridging material of claim 5, wherein, The temporary plugging material usage rate is determined by the following formula 6: Formula 6: Wherein, η 暂堵材料 is the use rate of temporary plugging material, %; m 封堵 is the amount of temporary plugging material for plugging the perforation, g; m 总 is the total amount of temporary plugging material injection, g.

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