Solid acid online mixing device and implementation method

Abstract

The invention discloses a solid acid online mixing device and an implementation method. The device comprises a small-sized acidification pump, the small-sized acidification pump is connected with an on-line stirring liquid preparation tank through a low-pressure pipeline, and the on-line stirring liquid preparation tank is connected with a solid acid pneumatic charging machine. The device is used in cooperation with an instant solid acid material with acetic acid and hydrofluoric acid as main raw materials, the solid acid material is sucked into the stirring liquid preparation tank through the solid acid pneumatic charging machine, water is added into the stirring liquid preparation tank for online dissolution preparation, the acid liquid is pumped into an oil field production well through the acidification pump, the solid acid online mixing step is repeated, and the solid acid online mixing process is completed. And the solid acid acidification construction operation is completed. According to the invention, high-speed online mixing and equipment miniaturization can be realized, and the device is suitable for limited operation spaces such as an offshore platform and the like; instant solid acid with the concentration ratio as high as 1 / 20 is adopted as a construction material, and the method has the high-efficiency acidification characteristics of the same time and equivalent effect as the existing acidification operation.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield acid plugging removal, and in particular to a high-speed and high-efficiency solid acid online mixing device and an implementation method. Background Art

[0002] Acidizing and plugging removal technology is an important means to increase oilfield production and injection. It has the advantages of low cost and wide adaptability. It is currently widely used in oilfields, but there are also a series of problems. For example, China's offshore oilfields have limited operating space. As the number of acidizing wells continues to increase, acidizing equipment and acidizing materials need to occupy a large amount of deck space, affecting the timeliness of other deck operations and greatly affecting production. The use of tugboats to carry acidizing materials has the disadvantages of high costs and high risks of operations in waves and strong winds.

[0003] The use of high-efficiency liquid acid or solid acid online acidification is a solution adopted by oil fields. For example, Chinese invention patent 201210337567.9 "Online single-step acidification technology for water injection wells in offshore oil fields" and "Liu Pingli, Zhang Lu, Pan Yiyong, etc. Single-step online acidification technology for water injection wells in offshore oil fields [J]. Journal of Southwest Petroleum University (Natural Science Edition). 2014, 36 (5): 148-154." focuses on the online single-step acidification of water injection wells. The process technology uses 20-40% industrial acetic acid, 15-40% industrial hydrochloric acid, 3-15% precipitation inhibitor, 5-15% drainage aid, 3-15% corrosion inhibitor, 5-15% anti-swelling agent, 5-15% iron ion stabilizer, and 2-10% hydrofluoric acid to prepare a single-step acid solution, and pumps the single-step acid solution into the water injection process. The ratio of the acid injection volume to the water injection volume is 1:2 to 2:5 by volume. The above method can achieve efficient, rapid and large-scale blockage resolution of offshore oil field water injection wells.

[0004] However, the current technology has the following problems: 1) The number of acidizing equipment has been reduced, and when acidizing multiple wells is required, the platform space occupied is still large; 2) 2 to 3 m 3 / h low pumping volume of small acidizing pumps, and the use of a small amount of acid liquid, reduce the occupied space, but it is difficult to achieve the same effect as conventional acidizing. In addition, the acidizing operation time is extended from 2 to 3 hours to 6 to 10 hours or even longer; 3) aminosulfonic acid, organic phosphonic acid, aminocarboxylate, etc. are used as solid acid, mainly for moderate dissolution or anti-scaling, and the acidification effect is difficult to guarantee; 4) solid acid is dissolved into liquid, or artificial feeding or spiral feeding is used, there is a risk of strong wind blowing the solid acid away, corroding the platform and personnel, and the risk of solid acid getting damp and causing the feeding equipment to get stuck and unable to operate. In addition, the manual feeding method is difficult to guarantee the dosing rate and brings a high-intensity construction labor burden.

[0005] Therefore, there is currently a lack of a fast and efficient acidizing operation solution that can effectively solve the problem of fast and efficient acidizing operation in the confined space of the platform using small acidizing equipment and materials, so as to further reduce the spatial area of ​​the acidizing operation, and on the basis of ensuring the acidizing effect, realize the miniaturization of the acidizing operation equipment and the reduction of the amount of construction acidizing agents. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a solid acid online mixing device and implementation method. The present invention adopts a small acidizing pump with moderate displacement and a 5m 3 Online stirring and mixing tanks and instant solid acid with a concentration ratio of up to 1 / 20 are used as construction materials. The online mixing method is used to greatly reduce the space required for acidification operations. The overall operation time does not exceed 3 hours. The amount and concentration of the diluted acid are basically the same as conventional acidification, which can achieve equivalence with conventional acidification. High-concentration instant solid acid with acetic acid as the main body and hydrofluoric acid as the main raw materials is used as construction materials to effectively ensure the operation effect. A solid acid pneumatic feeder is used to effectively avoid a series of problems such as the difficulty of solid acid feeding on offshore platforms, high safety risks, and high labor intensity.

[0007] In a first aspect, the present invention provides a solid acid online mixing device, which is realized by adopting the following technical scheme.

[0008] A solid acid online mixing device comprises a small acidizing pump, which is connected to the wellhead of an oil field production well through a high-pressure pipeline; the small acidizing pump is connected to an online stirring and liquid preparation tank through a low-pressure pipeline, and the online stirring and liquid preparation tank is connected to a solid acid pneumatic feeder; the solid acid pneumatic feeder comprises a feeding funnel connected to the online stirring and liquid preparation tank, and the feeding funnel is connected to a container carrying solid acid material through a feeding hose; the feeding funnel is also connected to an air extraction pump through an air extraction hose.

[0009] Furthermore, a low-pressure butterfly valve is provided on the low-pressure pipeline.

[0010] Furthermore, a high-pressure stopcock is provided on the high-pressure pipeline.

[0011] Furthermore, the online stirring and liquid preparation tank is provided with a water adding port and a solid adding port.

[0012] Furthermore, an agitator is provided in the online stirring liquid preparation tank.

[0013] Furthermore, a filter is provided between the feeding funnel and the air extraction hose.

[0014] Furthermore, the small acidification pump has a maximum displacement of 20m 3 / h, an acid-resistant injection pump with a maximum pumping pressure of not less than 15MPa.

[0015] In a second aspect, the present invention provides a method for implementing online mixing of solid acid, which is achieved by adopting the following technical scheme.

[0016] A solid acid online mixing implementation method comprises the following steps:

[0017] S1. Start the solid acid pneumatic feeder, suck 0.25t of acetic acid type instant solid acid into the online mixing tank through the feeding hose, and add water to 5m 3 , after stirring for 3-10 minutes, start the small acidification pump;

[0018] S2. Continuously inhale acetic acid type instant solid acid and follow the formula: 1t solid acid material: 10m 3 Water ratio, continue to add water through the water inlet until all the first section of construction materials are pumped in, then stop the pump;

[0019] S3. Replace the feeding hose to the mixed solid acid material of acetic acid type and hydrofluoric acid type in a mass ratio of 1:1, repeat steps S1 and S2 until all the second section construction materials are pumped in, and stop the pump.

[0020] Furthermore, the preparation method of the acetic acid type instant solid acid is: hydrazine with a mass fraction of 80%, acetic acid with a mass fraction of more than 99.5%, and anhydrous ethanol are mixed in a mass ratio of 1:2.5:(12-15), filtered, and dried to obtain the obtained product; the preparation method of the hydrofluoric acid type instant solid acid is: hydrazine with a mass fraction of 80%, hydrofluoric acid with a mass fraction of more than 40%, and anhydrous ethanol are mixed in a mass ratio of 1:2:(12-15), filtered, and dried to obtain the obtained product.

[0021] Furthermore, the acetic acid type instant solid acid material shall not exceed 3 tons, the operation time for pumping all the materials in the first stage of construction shall not exceed 1.5 hours, and the cumulative injection volume shall not exceed 30m 3 The mixed solid acid material of acetic acid and hydrofluoric acid shall not exceed 3t, the operation time of pumping all the materials in the second stage of construction shall not exceed 1.5h, and the cumulative injection volume shall not exceed 30m 3 .

[0022] This application has the following beneficial effects.

[0023] 1) The device and implementation method of the present invention can achieve high-speed online mixing, and the equipment is miniaturized, which is suitable for limited working spaces such as offshore platforms;

[0024] 2) The present invention uses instant solid acid with a concentration ratio of up to 1 / 20 as the construction material, which has the characteristics of high-efficiency acidification with the same operation time and equivalent effect as the existing acidification;

[0025] 3) The present invention can effectively avoid the risks of existing solid acid operation under strong wind conditions on offshore platforms, as well as the problem that the solid acid material is difficult to be fed by conventional feeding equipment due to moisture. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] Among them, 1. Small acidizing pump; 2. Online stirring and dispensing tank; 2-1. Agitator; 2-2. Water inlet; 2-3. Solid addition port; 3. Solid acid pneumatic feeder; 3-1. Feeding hose; 3-2. Feeding funnel; 3-3. Filter; 3-4. Vacuum hose; 3-5. Vacuum pump; 4. High-pressure pipeline; 5. Low-pressure pipeline; 6. High-pressure plug valve; 7. Low-pressure butterfly valve; 8. Solid acid material; 9. Wellhead. DETAILED DESCRIPTION

[0028] The present patent application is further described below in conjunction with embodiments.

[0029] like Figure 1 As shown, a solid acid online mixing device includes a small acidizing pump 1, an online stirring liquid preparation tank 2, and a solid acid pneumatic feeder 3.

[0030] The small acidizing pump 1 is connected to the online stirring and liquid dispensing tank 2 by a low-pressure pipeline 5, and a low-pressure butterfly valve 7 is provided on the pipeline. The small acidizing pump 1 is connected to the wellhead 9 of the oil field production well by a high-pressure pipeline 4, and a high-pressure plug valve 6 is provided on the pipeline.

[0031] The small acidification pump 1 of this application adopts a maximum displacement of 20m 3 / h, an acid-resistant injection pump with a maximum pumping pressure of not less than 15MPa.

[0032] The online stirring liquid preparation tank 2 is made of acid-resistant material and has a capacity of 5m 3 , and is also equipped with a stirrer 2-1, a water inlet 2-2, and a solid addition inlet 2-3;

[0033] The solid acid pneumatic feeder 3 includes a feeding hose 3-1, a feeding funnel 3-2, a filter 3-3, an exhaust hose 3-4, and an exhaust pump 3-5. After startup, the maximum feeding speed is not less than 2t / h. The feeding funnel 3-2 is inserted into the solid addition port 2-3 of the online stirring liquid preparation tank 2 to suck the solid acid material 8 into the online stirring liquid preparation tank 2.

[0034] The solid acid material 8 is a special material for the solid acid online mixing device of the present application. The solid acid material 8 is an instant solid acid with acetic acid as the main raw material and hydrofluoric acid as the main raw material, that is, hydrazine with a mass fraction of 80%, acetic acid with a mass fraction of more than 99.5%, and anhydrous ethanol are mixed in a mass ratio of 1:2.5:12.5, filtered, and dried to obtain solid acetic acid; hydrazine with a mass fraction of 80%, hydrofluoric acid with a mass fraction of more than 40%, and anhydrous ethanol are mixed in a mass ratio of 1:2:12.5, filtered, and dried to obtain solid hydrofluoric acid. The solid acid material dissolves in water for less than 3 minutes and has a solubility of not less than 30%.

[0035] Example 1 (the total amount of acid solution is 60m 3 , construction work 3h)

[0036] A solid acid online mixing implementation method comprises the following steps:

[0037] Step 1, start the solid acid pneumatic feeder 3, suck 0.25t of acetic acid type instant solid acid into the online stirring liquid preparation tank 2 through the feeding hose 3-1, and add water to 5m 3 , after stirring for 3 minutes, start the small acidification pump 1;

[0038] Step 2: Continuously inhale acetic acid type instant solid acid and follow the formula: 1t solid acid material: 10m 3 Water ratio, continue to add water through the water inlet 2-2 until all the first section of construction materials are pumped in, then stop the pump;

[0039] Step 3, replace the feeding hose 3-1 to the mixed solid acid material of acetic acid type and hydrofluoric acid type in a mass ratio of 1:1, repeat steps 1 and 2 until all the second section construction materials are pumped in, and stop the pump.

[0040] The acetic acid type instant solid acid material is 3 tons. The operation time for pumping all the materials in the first stage is 1.5 hours, and the cumulative injection volume is 30m 3 ; The mixed solid acid material of acetic acid type and hydrofluoric acid type in a mass ratio of 1:1 is 3 tons. The operation time for pumping all the materials in the second stage of construction is 1.5 hours, and the cumulative injection volume is 30m 3 .

[0041] Compared with conventional acidizing, the injection volume is generally 30 to 60 m 3 The operation time is 1 to 4 hours. The solid acid injection volume in this embodiment is 60m 3 The operation time is 3 hours, which basically achieves the equivalent operation efficiency and dilution concentration of conventional acidification; at the same time, a total of 6 tons of solid acid materials are constructed, and the liquid preparation tank occupies an area of ​​5m 3, which is much smaller than the current conventional acidizing materials of 15-30t, and the liquid distribution tank occupies an area of ​​30-60m 3 .

[0042] Example 2 (the total amount of acid solution is 40m 3 , construction work 2h)

[0043] A solid acid online mixing implementation method comprises the following steps:

[0044] Step 1, start the solid acid pneumatic feeder 3, suck 0.25t of acetic acid type instant solid acid into the online stirring liquid preparation tank 2 through the feeding hose 3-1, and add water to 5m 3 , after stirring for 3 minutes, start the small acidification pump 1;

[0045] Step 2: Continuously inhale acetic acid type instant solid acid and follow the formula: 1t solid acid material: 10m 3 Water ratio, continue to add water through the water inlet 2-2 until all the first section of construction materials are pumped in, then stop the pump;

[0046] Step 3, replace the feeding hose 3-1 to the mixed solid acid material of acetic acid type and hydrofluoric acid type in a mass ratio of 1:1, repeat steps 1 and 2 until all the second section construction materials are pumped in, and stop the pump.

[0047] The acetic acid type instant solid acid material is 2 tons. The operation time for pumping all the materials in the first stage is 1 hour, and the cumulative injection volume is 20m 3 ; The mixed solid acid material of acetic acid type and hydrofluoric acid type in a mass ratio of 1:1 is 2t. The operation time for pumping all the materials in the second stage is 1h, and the cumulative injection volume is 20m 3 .

[0048] Compared with conventional acidizing, the injection volume is generally 30 to 60 m 3 The operation time is 1 to 4 hours. The solid acid injection volume in this embodiment is 40m 3 The operation time is 2 hours, which basically achieves the equivalent operation efficiency and dilution concentration of conventional acidification; at the same time, a total of 4 tons of solid acid materials are constructed, and the liquid preparation tank occupies an area of ​​5m 3 , which is much smaller than the current conventional acidizing materials of 15-30t, and the liquid distribution tank occupies an area of ​​30-60m 3 .

[0049] Example 3 (the total amount of acid solution is 30m 3 , construction work 1.5h)

[0050] A solid acid online mixing implementation method comprises the following steps:

[0051] Step 1, start the solid acid pneumatic feeder 3, suck 0.25t of acetic acid type instant solid acid into the online stirring liquid preparation tank 2 through the feeding hose 3-1, and add water to 5m 3 , after stirring for 3 minutes, start the small acidification pump 1;

[0052] Step 2: Continuously inhale acetic acid type instant solid acid and follow the formula: 1t solid acid material: 10m 3 Water ratio, continue to add water through the water inlet 2-2 until all the first section of construction materials are pumped in, then stop the pump;

[0053] Step 3, replace the feeding hose 3-1 to the mixed solid acid material of acetic acid type and hydrofluoric acid type in a mass ratio of 1:1, repeat steps 1 and 2 until all the second section construction materials are pumped in, and stop the pump.

[0054] The acetic acid type instant solid acid material is 1.5t, the operation time for pumping all the materials in the first stage is 0.75h, and the cumulative injection volume is 15m 3 ; The mixed solid acid material of acetic acid type and hydrofluoric acid type in a mass ratio of 1:1 is 1.5t. The operation time for pumping all the materials in the second stage is 0.75h, and the cumulative injection volume is 15m 3 .

[0055] Compared with conventional acidizing, the injection volume is generally 30 to 60 m 3 The operation time is 1 to 4 hours. The solid acid injection volume in this embodiment is 30m 3 The operation time is 1.5 hours, which basically achieves the equivalent operation efficiency and dilution concentration of conventional acidification; at the same time, a total of 3 tons of solid acid materials are constructed, and the liquid preparation tank occupies an area of ​​5m 3 , which is much smaller than the current conventional acidizing materials of 15-30t, and the liquid distribution tank occupies an area of ​​30-60m 3 .

[0056] The operation time and the concentration used in the present invention are basically the same as those of the existing acidification, and the occupied area can be greatly reduced. The saved space area is obtained by subtracting 5 from the volume of the acid, which is advantageous for offshore or space-constrained sites.

[0057] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A solid acid online mixing device, characterized in that: The invention comprises a small acidizing pump (1), which is connected to a wellhead (9) of an oilfield production well via a high-pressure pipeline (4); the small acidizing pump (1) is connected to an online stirring and liquid preparation tank (2) via a low-pressure pipeline (5), and the online stirring and liquid preparation tank (2) is connected to a solid acid pneumatic feeder (3); the solid acid pneumatic feeder (3) comprises a feeding funnel (3-2) connected to the online stirring and liquid preparation tank (2), and the feeding funnel (3-2) is connected to a container carrying a solid acid material (8) via a feeding hose (3-1); the feeding funnel (3-2) is also connected to an air extraction pump (3-5) via an air extraction hose (3-4).

2. A solid acid online mixing device according to claim 1, characterized in that: The low-pressure pipeline (5) is provided with a low-pressure butterfly valve (7).

3. A solid acid online mixing device according to claim 1, characterized in that: The high-pressure pipeline (4) is provided with a high-pressure stopcock (6).

4. A solid acid online mixing device according to claim 1, characterized in that: The online stirring liquid preparation tank (2) is provided with a water adding port (2-2) and a solid adding port (2-3).

5. A solid acid online mixing device according to claim 1, characterized in that: The online stirring liquid preparation tank (2) is provided with a stirrer (2-1).

6. A solid acid online mixing device according to claim 1, characterized in that: A filter (3-3) is provided between the feeding funnel (3-2) and the air extraction hose (3-4).

7. A solid acid online mixing device according to claim 1, characterized in that: The small acidification pump (1) has a maximum displacement of 20m 3 / h, an acid-resistant injection pump with a maximum pumping pressure of not less than 15MPa.

8. A solid acid online mixing implementation method, characterized in that: The following steps are involved: S1. Start the solid acid pneumatic feeder (3), suck 0.25t of acetic acid-type instant solid acid into the online stirring tank through the feed hose (3-1), and add water to 5m through the water inlet (2-2). 3 , after stirring for 3-10 minutes, start the small acidification pump (1); S2. Continuously inhale acetic acid type instant solid acid and follow the formula: 1t solid acid material: 10m 3 The water ratio is adjusted by continuously adding water through the water inlet (2-2) until all the first section construction materials are pumped in, and then the pump is stopped; S3. Replace the feeding hose (3-1) to the mixed solid acid material of acetic acid type and hydrofluoric acid type in a mass ratio of 1:1, repeat steps S1 and S2 until all the second stage construction materials are pumped in, and stop the pump.

9. A solid acid online mixing implementation method according to claim 8, characterized in that: The preparation method of acetic acid type instant solid acid is as follows: hydrazine with a mass fraction of 80%, acetic acid with a mass fraction of 99.5% or more, and anhydrous ethanol are mixed in a mass ratio of 1:2.5:(12-15), filtered, and dried to obtain the obtained product; the preparation method of hydrofluoric acid type instant solid acid is as follows: hydrazine with a mass fraction of 80%, hydrofluoric acid with a mass fraction of 40% or more, and anhydrous ethanol are mixed in a mass ratio of 1:2:(12-15), filtered, and dried to obtain the obtained product.

10. A solid acid online mixing implementation method according to claim 8, characterized in that: The acetic acid type instant solid acid material shall not exceed 3 tons. The operation time for pumping all the materials in the first stage of construction shall not exceed 1.5 hours, and the cumulative injection volume shall not exceed 30m 3 The mixed solid acid material of acetic acid and hydrofluoric acid shall not exceed 3t, the operation time of pumping all the materials in the second stage of construction shall not exceed 1.5h, and the cumulative injection volume shall not exceed 30m 3 .

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