Evaluation device and evaluation method for stability of acid fracturing high-temperature temporary plugging agent

[0045] like Figure 1-3 shown, figure 1 A schematic structural diagram of a specific embodiment of an evaluation device for the stability of an acid pressure high temperature temporary plugging agent provided by the present invention; figure 2 In order to evaluate the stability of the first temporary plugging agent solution, the flow chart of the infiltration from the high-permeability slate and the low-permeability slate is measured, in which the curve 16 is the flow rate from the high-permeability slate, and the curve 17 is The flow of seepage from low permeability slate; image 3 In order to evaluate the stability of the second temporary plugging agent solution, the flow chart of the infiltration from the high-permeability slate and the low-permeability slate is measured, wherein the curve 18 is the flow rate from the high-permeability slate, and the curve 19 is The flow of seepage from low-permeability slate.

[0046] combine figure 1 , an evaluation device for the stability of acid pressure high temperature temporary plugging agent, which includes a liquid supply part, the liquid supply part is used to provide mixed acid solution and temporary plugging agent solution, and also includes a liquid supply part downstream and through the liquid supply part. The test part where the pipeline with the valve is connected to the liquid supply part, the test part includes a rock plate holder 1, and the rock plate holder 1 includes a high-permeability rock plate 2, a low-permeability rock plate 3 and four plywood , two of the splints hold the high-permeability rock slab 2, the remaining two splints hold the low-permeability rock slab 3, and the rock slab holder 1 is located downstream of the liquid supply part and the A heating part and a pressurizing part are provided on the pipeline connecting the rock plate holder 1 with the liquid supply part. The heating part is used for heating the mixed acid solution and the temporary plugging agent solution, and the pressurizing part is used for The mixed acid solution and the temporary plugging agent solution are pressurized, and also includes connecting the liquid supply part through a pipeline and providing power to make the acid solution and the temporary plugging agent solution flow from the liquid supply part to the place. The power part of the rock plate holder 1, the outlet of the high-permeability rock plate 2 is connected to the high-permeability pipeline on which the first flow meter 4 is arranged, and the liquid seeping from the high-permeability rock plate 2 flows through the high-permeability rock plate 2. The first flow meter 4, the outlet of the low-permeability rock slab 3 is connected to the low-permeability pipeline on which the second flow meter 5 is arranged, and the liquid exuded from the low-permeability rock slab 3 flows through the second flow meter 5 .

[0047] The provided evaluation device can complete the whole process from the mixing of acid solution and temporary plugging agent solution to the stability test of temporary plugging agent. The mixed liquid is heated and pressurized by the heating part and the pressurizing part to simulate the high temperature and pressure of the reservoir. The rock slab holder 1 of the present invention holds the high-permeability rock slab 2 and the low-permeability rock slab 3, and whether the temporary plugging agent blocks the high-permeability rock slab can be evaluated by the outlet flow of the two rock slabs at the same time. Then the stability of the temporary plugging agent was evaluated. In addition, different temporary plugging agents can be evaluated to achieve horizontal comparison of the effects of different temporary plugging agents, and then the best temporary plugging agent can be selected.

[0048] In a specific embodiment, as figure 1 As shown, the test section also includes an inlet pressure gauge 6, a pressure gauge 7 at the contact point of the rock slab, and an outlet pressure gauge 8. The inlet pressure gauge 6 is arranged at the inlet of the high-permeability rock slab 2, and the pressure gauge 7 at the contact point of the rock slab is set at the high-permeability rock slab. Between the slate 2 and the low-permeability slate 3 , an outlet pressure gauge 8 is provided at the outlet of the low-permeability slate 3 .

[0049] There is an inlet pressure gauge 6, a pressure gauge 7 at the contact point of the rock slab, and an outlet pressure gauge 8, which are used to detect whether the pipeline, the high-permeability rock slab 2 is tightly clamped, and whether the low-permeability rock slab 3 is tightly clamped. Evaluation of the stability of the temporary plugging agent solution provides a guarantee.

[0050] Further, in this specific embodiment, the testing part also includes a filtrate collection part 9, which is connected to the rock plate holder 1 through a pipeline, and is used to collect the filtrate of the high-permeability rock plate 2 and the low-permeability rock plate 3. liquid.

[0051] A filtrate collection part 9 is provided, which effectively simulates the filtration loss of acid solution under the real conditions of the reservoir, and more truly evaluates the performance of the temporary plugging agent solution under the acid pressure state.

[0052] Regarding the liquid supply part, in this specific embodiment, as figure 1 As shown, it includes an acid liquid bottle 10, a temporary plugging agent solution storage container 11 and a magnetic stirrer 12, and the acid liquid bottle 10 and the temporary plugging agent solution storage container 11 are connected to the magnetic stirrer 12 through pipelines, and the acid liquid The bottle 10 is used to hold the acid solution, the temporary plugging agent solution storage container 11 is used to hold the temporary plugging agent solution, and the magnetic stirrer 12 is provided with a magnetic drive rotor. Of course, it is not limited to this, as long as the acid solution and the temporary plugging agent solution can be mixed.

[0053] Further, the heating part is three adjustable heating sheets 13 arranged in series.

[0054] like figure 1 As shown, the other ends of the high permeation pipeline and the low permeation pipeline are both connected to a waste liquid bottle 14 for recovering the permeated liquid.

[0055] In this specific embodiment, the pressurizing part and the power part are integrally formed, which is the pressurizing pump 15, and the pressurizing pump 15 is made of hash alloy.

[0056] The pressurizing part and the power part are integrally formed, which simplifies the device and reduces the cost.

[0057] The invention also provides a method for evaluating the stability of the acid pressure high temperature temporary plugging agent, comprising the following steps:

[0058] a. Provide an evaluation device for the stability of the above-mentioned acid pressure high temperature temporary plugging agent;

[0059] b. Open the valve and the power part, so that the mixed acid solution and the temporary plugging agent solution flow out of the liquid supply part;

[0060] c. Turn on the heating part and the pressurizing part, and heat and pressurize the mixed acid solution and the temporary plugging agent solution flowing out from the liquid supply part, and heat and pressurize to a preset temperature and pressure;

[0061] d. The heated and pressurized mixed acid solution and the temporary plugging agent solution enter the slate holder 1, and penetrate into the high-permeability slate 2 and the low-permeability slate 3, continuously synchronizing Record the readings of the first flowmeter 4 and the second flowmeter 5, and compare the readings of the first flowmeter 4 and the second flowmeter 5 at the same time;

[0062] e. Evaluate the stability of acid pressure high temperature temporary plugging agent based on the following:

[0063] At the beginning of the test, the reading of the first flow meter 4 is greater than the reading of the second flow meter 5, that is, the seepage liquid of the high-permeability rock slab 2 is higher than that of the low-permeability rock slab 3; Entering, the seepage liquid from the high-permeability rock slab 2 slowly drops, the low-permeability rock slab 3 seeps the liquid slowly rises, and the seepage liquid from the two rock slabs tends to be stable, the readings of the first flowmeter 4 and the second flowmeter 5 The readings are similar, indicating that the temporary plugging agent solution has good stability under the high temperature condition of the acid pressure; or,

[0064] At the beginning of the test, the reading of the first flow meter 4 is greater than the reading of the second flow meter 5, that is, the seepage liquid of the high-permeability rock slab 2 is higher than the low-permeability rock slab 3; Entering, the liquid seeping from the high-permeability rock slab 2 slowly drops, the liquid seeping from the low-permeability rock slab 3 rises slowly, and the liquid seeping from the two rock slabs tends to be stable; but after a period of time, the reading of the first flow meter 4 tends to becomes larger, and the reading of the second flow meter 5 tends to become smaller, indicating that the stability of the temporary plugging agent solution under the high temperature of the acid pressure is poor.

[0065] Through the two situations in step e, the stability of the temporary plugging agent solution can be measured.

[0066] Further, in step a: provide the above-mentioned evaluation device for the stability of the acid pressure high temperature temporary plugging agent with inlet pressure gauge 6, rock slab contact pressure gauge 7 and outlet pressure gauge 8, then in step d:

[0067] Before recording the readings of the first flow meter 4 and the second flow meter 5, check the reading of the inlet pressure gauge 6 to check whether the sealing of the pipeline before entering the rock plate holder 1 is normal, and check the pressure gauge 7 at the contact point of the rock plate To check whether the contact between the high-permeability rock slab 2 and the low-permeability rock slab 3 is tight, check whether the value of the outlet pressure gauge 8 is normal, and calculate the difference between the readings of the inlet pressure gauge 6 and the pressure gauge 7 at the contact point of the rock slab. value to judge whether the two plywoods tightly clamp the high-permeability slate 2, and calculate the difference between the readings of the pressure gauge 7 and the outlet pressure gauge 8 at the contact point of the slate to judge whether the other two plywood tightly clamp the low-permeability slate 3;

[0068] If all of the above are normal, start recording the readings of the first flow meter 4 and the second flow meter 5, and stop recording if any of the above items are abnormal during the recording period.

[0069] Further, in step a: provide the above-mentioned acid pressure high temperature temporary plugging agent stability evaluation device with acid bottle 10, temporary plugging agent solution storage container 11 and magnetic stirrer 12, then in step b:

[0070] The acid liquid used on the fracturing site is loaded into the acid liquid bottle 10, and the prepared temporary plugging agent solution to be measured is loaded into the temporary plugging agent solution storage container 11;

[0071]Connect the acid bottle 10 and the magnetic stirrer 12, connect the temporary plugging agent solution storage container 11 and the magnetic stirrer 12, pass the quantitative acid solution and the temporary plugging agent solution into the magnetic stirrer 12, and adjust the magnetic field strength of the magnetic stirrer 12 The rotation of the magnetic drive rotor is controlled to uniformly stir the acid solution and the temporary plugging agent solution to form the mixed acid solution and the temporary plugging agent solution.

[0072] The method for evaluating the stability of the acid pressure high temperature temporary plugging agent provided by the present invention adopts the device provided above for evaluation, so it has the same technical effect.

[0073] refer to figure 2 , which is the flow rate permeating from the high-permeability rock slab 2 and the low-permeability rock slab 3 measured when evaluating the stability of the first temporary plugging agent solution (using the evaluation device of the present invention) under the condition of a pressure of 10 MPa Change diagram, the evaluation process is as follows:

[0074] a. Put 1080ml of soil acid in the acid bottle 10, and put 100ml of the prepared temporary plugging agent solution to be measured in the temporary plugging agent solution storage container 11;

[0075] B, open the valve of the acid bottle 10 and the temporary plugging agent solution storage container 11 respectively and pass the acid liquid of 1080ml and the temporary plugging agent solution of 100ml into the magnetic stirrer 12, and uniformly stir the mixed liquid for 6 minutes;

[0076] c. Close the valve of the acid bottle 10 and the temporary plugging agent solution storage 11 container, and open the valve of the adjustable heating piece 13, so that the mixed liquid passes through the heating piece at a uniform speed, and the heating piece is set to a heating temperature of 80°C;

[0077] d. Control the pressurizing pump 15 to pressurize the reservoir pressure to 10MPa, and pump the pressurized liquid into the rock plate holder 1 with high and low permeability rock plates at a speed of 0.6ml/s;

[0078] e. Continuously measure the liquid seeping out from the high and low permeability rock slabs, and compare the flow differences (such as figure 2 );

[0079] f. During the measurement of flow, observe the readings of each pressure gauge. If there is an abnormal pressure drop, the experiment should be stopped immediately;

[0080] g. After the experiment, close the evaluation device and disconnect the pipeline.

[0081] In the above step e, when the readings of each pressure gauge are normal, start timing after both rock slabs generate flow, and record the flow rate of the first flow meter 4, the flow rate of the second flow meter 5, and the filtrate collection part 9 every 10s. The amount of liquid change in the medium, constant test for 30 minutes; it can be found that in the case of using the temporary plugging agent solution: such as figure 2 As shown, the seepage liquid of the high-permeability rock slab 2 is higher than that of the low-permeability rock slab 3; with the entry of the temporary plugging agent solution, the seepage liquid of the high-permeability rock slab 2 slowly decreases, and the seepage liquid of the low-permeability rock slab 3 slowly rises , reached a basic equilibrium value in about 16 minutes, and then the liquid seeping out from the two rock slabs tended to be stable; this shows that the temporary plugging agent solution has better stability under acid pressure and high temperature conditions.

[0082] refer to image 3 , which is the flow rate permeating from the high-permeability rock slab 2 and the low-permeability rock slab 3 measured when evaluating the stability of the second temporary plugging agent solution (using the evaluation device of the present invention) under the condition of a pressure of 10 MPa Change diagram, the evaluation process is as follows:

[0083] a. Put 1080ml of soil acid in the acid bottle 10, and put 100ml of the prepared temporary plugging agent solution to be measured in the temporary plugging agent solution storage container 11;

[0084] B, open the valve of the acid bottle 10 and the temporary plugging agent solution storage container 11 respectively and pass the acid liquid of 1080ml and the temporary plugging agent solution of 100ml into the magnetic stirrer 12, and uniformly stir the mixed liquid for 6 minutes;

[0085] c. Close the valve of the acid bottle 10 and the temporary plugging agent solution storage container 11, and open the valve of the adjustable heating sheet 13, so that the mixed liquid passes through the heating sheet at a uniform speed, and the heating sheet is set to a heating temperature of 80°C;

[0086] d. Control the pressurizing pump 15 to pressurize the reservoir pressure to 10MPa, and pump the pressurized liquid into the rock plate holder 1 with high and low permeability rock plates at a speed of 0.6ml/s;

[0087] e. Continuously measure the liquid seeping out from the high and low permeability rock slabs, and compare the flow differences between the two rock slabs;

[0088] f. Observe the readings of each pressure gauge. If there is an abnormal pressure drop, the experiment should be stopped immediately;

[0089] g. After the experiment, close the evaluation device and disconnect the pipeline.

[0090] In the above step e, when the readings of each pressure gauge are normal, start timing after both rock slabs generate flow, and record the flow rate of the first flow meter 4, the flow rate of the second flow meter 5, and the filtrate collection part 9 every 10s. The amount of liquid change in the medium, constant test for 30 minutes; it can be found that in the case of temporary plugging agent: such as image 3 As shown, the seepage liquid of the high-permeability rock slab 2 is higher than that of the low-permeability rock slab 3; with the entry of the temporary plugging agent solution, the seepage liquid of the high-permeability rock slab 2 slowly decreases, and the seepage liquid of the low-permeability rock slab 3 slowly rises , reached a basic equilibrium value in about 14 minutes; when the time reached 22 minutes, the seepage liquid of the high-permeability rock slab 2 began to show an upward trend; in the remaining test time, the seepage liquid of the high-permeability rock slab 2 gradually increased, and the low-permeability rock slab 2 The seepage liquid of plate 3 gradually decreased, indicating that the stability of the temporary plugging agent solution at high temperature was not good, and the temporary plugging agent solution was degraded and split.