阅读说明：本技术 一种裂缝暂堵转向剂及其在暂堵转向加砂压裂工艺中的应用 (Temporary fracture plugging diverter and application thereof in temporary plugging diverting sand fracturing process ) 是由 张锋三 郭庆 吴金桥 韩伟 白方林 孙晓 穆景福 张军涛 王振川 许亮 王卫刚 于 2021-08-31 设计创作，主要内容包括：本发明公开一种裂缝暂堵转向剂,由以下原料组成：聚丙烯酸钠、聚乙烯醇、聚碳酸酯、KCl、过硫酸铵,聚丙烯酰胺,水；针对致密储层中岩心脆性矿物含量不同,所述裂缝暂堵转向剂包括三种,分别为裂缝暂堵转向剂A、裂缝暂堵转向剂B、裂缝暂堵转向剂C。同时,本发明还公开所述裂缝暂堵转向剂在暂堵转向加砂压裂工艺中的应用。所述裂缝暂堵转向剂采用水溶性较好的聚合物材料,设计出“瞬间桥堵”的封堵方式,通过三种不同粒径聚合物的相互组合,快速形成可耐压封堵墙,实现其他甜点区裂缝的开启,进一步增大了裂缝改造体积,与常规暂堵方式相比,具有“堵得快、稳得住、易溶解”的特点。(The invention discloses a crack temporary plugging diverting agent, which consists of the following raw materials: sodium polyacrylate, polyvinyl alcohol, polycarbonate, KCl, ammonium persulfate, polyacrylamide and water; aiming at different rock core brittle mineral contents in compact reservoirs, the fracture temporary plugging diversion agent comprises three diversion agents, namely a fracture temporary plugging diversion agent A, a fracture temporary plugging diversion agent B and a fracture temporary plugging diversion agent C. Meanwhile, the invention also discloses application of the temporary plugging diversion agent for the cracks in a temporary plugging diversion sand adding fracturing process. The temporary crack plugging diverter is made of polymer materials with good water solubility, an instant bridging plugging mode is designed, a pressure-resistant plugging wall is quickly formed by mutually combining three polymers with different particle sizes, cracks in other dessert regions can be opened, the crack modification volume is further increased, and compared with a conventional temporary plugging mode, the temporary crack plugging diverter has the characteristics of being fast in plugging, stable in plugging and easy to dissolve.)

1. A crack temporary plugging diverter is characterized in that: the feed consists of the following raw materials: sodium polyacrylate, polyvinyl alcohol, polycarbonate, KCl, ammonium persulfate, polyacrylamide and water.

2. The fracture-bridging diverter of claim 1, wherein: the sodium polyacrylate is powder with the particle size of 100-200 meshes; the polyvinyl alcohol is sheet-shaped or flocculent; the polycarbonate is particles with the particle size of 2-4 mm; the polyacrylamide is emulsion polyacrylamide.

3. The fracture-bridging diverter of claim 2, wherein: the polyvinyl alcohol is polyvinyl alcohol 1799 or polyvinyl alcohol 1788.

4. The fracture-diverting agent according to claim 1, 2 or 3, characterized in that: aiming at different rock core brittle mineral contents in a compact reservoir, the fracture temporary plugging diversion agent comprises three types, namely a fracture temporary plugging diversion agent A, a fracture temporary plugging diversion agent B and a fracture temporary plugging diversion agent C, and the three types are calculated according to the weight percentage of 100 percent, and specifically comprise the following components:

aiming at a compact reservoir with the core brittle mineral content of more than 60%, the fracture temporary plugging diverting agent is a fracture temporary plugging diverting agent A and consists of the following raw materials in parts by weight: 0.05-0.1% of polyacrylamide, 0.75-1.75% of sodium polyacrylate, 2.0-3.0% of polyvinyl alcohol, 3.25-4.25% of polycarbonate, 0.5-1% of KCl, 0.05-0.15% of ammonium persulfate and the balance of water;

aiming at a compact reservoir with the core brittle mineral content of 40% -60%, the fracture temporary plugging diverting agent is a fracture temporary plugging diverting agent B and consists of the following raw materials in parts by weight: 0.05-0.1% of polyacrylamide, 0.75-1.75% of sodium polyacrylate, 3.25-4.25% of polyvinyl alcohol, 2.0-3.0% of polycarbonate, 0.5-1% of KCl, 0.05-0.15% of ammonium persulfate and the balance of water;

aiming at a compact reservoir with the core brittle mineral content of less than 40%, the fracture temporary plugging diverting agent is a fracture temporary plugging diverting agent C and consists of the following raw materials in parts by weight: 0.05-0.1% of polyacrylamide, 2.0-3.0% of sodium polyacrylate, 3.25-4.25% of polyvinyl alcohol, 0.75-1.75% of polycarbonate, 0.5-1% of KCl, 0.05-0.15% of ammonium persulfate and the balance of water.

5. The fracture-bridging diverter of claim 4, wherein:

the crack temporary plugging diversion agent A is prepared from the following raw materials in parts by weight: 0.1% of polyacrylamide, 1.25% of sodium polyacrylate, 2.50% of polyvinyl alcohol, 3.75% of polycarbonate, 1% of KCl, 0.1% of ammonium persulfate and the balance of water;

the crack temporary plugging diverting agent B is prepared from the following raw materials in parts by weight: 0.1% of polyacrylamide, 1.25% of sodium polyacrylate, 3.75% of polyvinyl alcohol, 2.50% of polycarbonate, 1% of KCl, 0.1% of ammonium persulfate and the balance of water;

the crack temporary plugging diversion agent C is composed of the following raw materials in parts by weight: 0.1 percent of polyacrylamide, 2.50 percent of sodium polyacrylate, 3.75 percent of polyvinyl alcohol, 1.25 percent of polycarbonate, 1 percent of KCl, 0.1 percent of ammonium persulfate and the balance of water.

6. The application of the fracture temporary plugging diverting agent as claimed in claim 4 in the temporary plugging diverting sand fracturing process is characterized in that: aiming at different rock core brittle mineral contents in a compact reservoir, different fracture temporary plugging diverting agents are matched and used, and when the rock core brittle mineral content in the compact reservoir is less than 40%, the fracture temporary plugging diverting agent C is adopted for sand fracturing; when the content of brittle minerals of the core in the compact reservoir is more than 60%, performing sand fracturing by adopting a fracture temporary plugging diverting agent A; when the content of brittle minerals of the rock core in the compact reservoir is 40% -60%, performing sand fracturing by adopting a crack temporary plugging diverting agent B; adjusting the construction discharge capacity to 1-2m before adding a crack temporary plugging diverting agent after sand fracturing³The rotational speed of a sand mixing tank of the sand mixing truck is more than 100r/min, the liquid level of the sand mixing tank does not exceed 2/3 scale marks, the crack temporary plugging diversion agent is prepared on site during adding, and the crack temporary plugging diversion agent is originally prepared during addingContinuously adding polyacrylamide, sequentially adding other raw materials of the crack temporary plugging diversion agent within 1-2min, and increasing the construction discharge capacity to 4-6m after the addition is finished³And min, after the construction pressure rises until the pressure is broken, adjusting the construction discharge capacity to the designed discharge capacity.

7. The application of the fracture temporary plugging diverting agent in the temporary plugging diverting sand fracturing process according to claim 6 is characterized in that: the process for performing sand fracturing by adopting the crack temporary plugging diversion agent A is the same as the process for performing sand fracturing by adopting the crack temporary plugging diversion agent B, and comprises the following steps:

(1) pumping the pad fluid;

(2) pumping sand carrying liquid;

(3) pumping a crack temporary plugging steering agent;

(4) pumping the pad fluid;

(5) pumping sand carrying liquid;

(6) pumping a crack temporary plugging steering agent;

(7) pumping the pad fluid;

(8) pumping sand carrying liquid;

(9) pumping displacement liquid: displacing the displacement fluid by 1.1 times of the volume of the well bore;

(10) closing the well for 2-24 h, starting to control open flow, and finishing the sand adding fracturing process after flowback is finished;

wherein, the liquid consumption of the pad fluid in the steps (1), (4) and (7) accounts for 30 percent of the total pad fluid: 30%: 40 percent; the proportion of the sand adding amount of the sand-carrying liquid in the steps (2), (5) and (8) to the total sand adding amount is 25%: 25%: 50 percent.

8. The use of the fracture diverting agent according to claim 7 in a diverting and sand fracturing process, characterized in that: the dosage of the crack temporary plugging diverter in the step (3) accounts for 0.3-0.8% of the total amount of the pad fluid and the sand-carrying fluid in the steps (1) and (2); the dosage of the crack temporary plugging diverter in the step (6) is the same as that of the crack temporary plugging diverter in the step (3).

9. The application of the fracture temporary plugging diverting agent in the temporary plugging diverting sand fracturing process according to claim 6 is characterized in that: the process for performing sand fracturing by adopting the fracture temporary plugging diversion agent C comprises the following steps:

(1c) pumping the pad fluid;

(2c) pumping sand carrying liquid;

(3c) pumping a crack temporary plugging steering agent;

(4c) pumping the pad fluid;

(5c) pumping sand carrying liquid;

(6c) pumping sand carrying liquid;

(7c) pumping displacement liquid: displacing the displacement fluid by 1.1 times of the volume of the well bore;

(8c) closing the well for 2-24 h, starting to control open flow by adopting oil nozzles of 3mm, 5mm and 8mm, and finishing the sand fracturing process after flowback is finished;

wherein, the liquid consumption of the pad fluid in the steps (1 c) and (4 c) accounts for 60 percent of the total pad fluid: 40%, the proportion of the sand adding amount of the sand-carrying liquid in the steps (2 c) and (5 c) to the total sand adding amount is 70%: 30 percent.

10. The application of the fracture temporary plugging diverting agent in the temporary plugging diverting and sand fracturing process according to claim 9 is characterized in that: the dosage of the crack temporary plugging diversion agent in the step (3 c) accounts for 0.3-0.8% of the total amount of the pad fluid and the sand-carrying fluid in the steps (1 c) and (2 c).

Technical Field

The invention belongs to the technical field of petroleum fracturing, and particularly relates to a temporary plugging diverting agent for a crack and application thereof in a temporary plugging diverting sand-adding fracturing process.

Background

Unconventional oil and gas become main resources for oil and gas development at home and abroad, and in recent two years, tight reservoir reconstruction mainly increases the reservoir reconstruction volume by realizing close cut-in of reservoir desserts through multiple clusters of perforation. The reservoir tight cutting technology increases the number of the perforation and causes the phenomenon of uneven liquid inlet amount of perforation clusters, thereby causing the problems of stress shadow in the reservoir and transition transformation of the reservoir. Geological reserves are not fully and effectively used, and the difference between the fracturing modification effect and the geological expectation is large.

According to the analysis on the fracturing process, the length of a single section of the horizontal well reaches 80-100m, the interval between clusters is 15-30m, the single-hole liquid inlet amount cannot meet the requirement of net pressure required by crack formation when the single-section general fracturing is carried out, and the single-cluster transformation scale must be increased by means of crack temporary plugging in a flow limiting mode, so that the crack temporary plugging is adopted in the multi-section multi-cluster fracturing technology of the horizontal well to increase the volume of the fracture network transformation.

At present, the conventional temporary plugging wall is mainly formed by using an expansion type material or profile control water plugging resin, and has the defects of long temporary plugging time, low pressurization speed and difficulty in dissolution; according to material analysis, the temporary plugging material adopted in the market at present is mainly gel block polyacrylic acid, and the problems of incomplete degradation, unobvious temporary plugging effect or incapability of adding sand after temporary plugging exist through field application. From the aspects of the universality of the process and the defects of materials, the research of the crack temporary plugging material for directional temporary plugging is imminent, and the development direction of the industry is to form the adaptive crack temporary plugging process technology.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a temporary plugging diversion agent for a crack and application thereof in a temporary plugging diversion sand adding fracturing process, wherein the temporary plugging diversion agent can realize the functions of quickly temporary plugging and restarting a new crack in the fracturing construction process.

A crack temporary plugging diverter is composed of the following raw materials: sodium polyacrylate, polyvinyl alcohol, polycarbonate, KCl, ammonium persulfate, polyacrylamide and water.

Preferably, the sodium polyacrylate is powder with the particle size of 100-200 meshes; the polyvinyl alcohol is sheet-shaped or flocculent; the polycarbonate is particles with the particle size of 2-4 mm; the polyacrylamide is emulsion polyacrylamide.

Preferably, the polyvinyl alcohol is polyvinyl alcohol 1799 or polyvinyl alcohol 1788.

Preferably, aiming at different rock core brittle mineral contents in a compact reservoir, the fracture temporary plugging diversion agent comprises three diversion agents, namely a fracture temporary plugging diversion agent A, a fracture temporary plugging diversion agent B and a fracture temporary plugging diversion agent C, and the diversion agents are calculated according to the weight percentage of 100 percent and specifically comprise the following components:

aiming at a compact reservoir with the core brittle mineral content of more than 60%, the fracture temporary plugging diverting agent is a fracture temporary plugging diverting agent A and consists of the following raw materials in parts by weight: 0.05-0.1% of polyacrylamide, 0.75-1.75% of sodium polyacrylate, 2.0-3.0% of polyvinyl alcohol, 3.25-4.25% of polycarbonate, 0.5-1% of KCl, 0.05-0.15% of ammonium persulfate and the balance of water;

aiming at a compact reservoir with the core brittle mineral content of 40% -60%, the fracture temporary plugging diverting agent is a fracture temporary plugging diverting agent B and consists of the following raw materials in parts by weight: 0.05-0.1% of polyacrylamide, 0.75-1.75% of sodium polyacrylate, 3.25-4.25% of polyvinyl alcohol, 2.0-3.0% of polycarbonate, 0.5-1% of KCl, 0.05-0.15% of ammonium persulfate and the balance of water;

aiming at a compact reservoir with the core brittle mineral content of less than 40%, the fracture temporary plugging diverting agent is a fracture temporary plugging diverting agent C and consists of the following raw materials in parts by weight: 0.05-0.1% of polyacrylamide, 2.0-3.0% of sodium polyacrylate, 3.25-4.25% of polyvinyl alcohol, 0.75-1.75% of polycarbonate, 0.5-1% of KCl, 0.05-0.15% of ammonium persulfate and the balance of water.

More preferably, the fracture temporary plugging diversion agent A is prepared from the following raw materials in parts by weight: 0.1% of polyacrylamide, 1.25% of sodium polyacrylate, 2.50% of polyvinyl alcohol, 3.75% of polycarbonate, 1% of KCl, 0.1% of ammonium persulfate and the balance of water;

the crack temporary plugging diverting agent B is prepared from the following raw materials in parts by weight: 0.1% of polyacrylamide, 1.25% of sodium polyacrylate, 3.75% of polyvinyl alcohol, 2.50% of polycarbonate, 1% of KCl, 0.1% of ammonium persulfate and the balance of water;

the crack temporary plugging diversion agent C is composed of the following raw materials in parts by weight: 0.1 percent of polyacrylamide, 2.50 percent of sodium polyacrylate, 3.75 percent of polyvinyl alcohol, 1.25 percent of polycarbonate, 1 percent of KCl, 0.1 percent of ammonium persulfate and the balance of water.

The application of the temporary plugging diversion agent for the fracture in the temporary plugging diversion sand fracturing process specifically comprises the following steps: aiming at different rock core brittle mineral contents in a compact reservoir, different fracture temporary plugging diverting agents are matched and used, and when the rock core brittle mineral content in the compact reservoir is less than 40%, the fracture temporary plugging diverting agent C is adopted for sand fracturing; when the content of brittle minerals of the core in the compact reservoir is more than 60%, performing sand fracturing by adopting a fracture temporary plugging diverting agent A; when the content of brittle minerals of the rock core in the compact reservoir is 40% -60%, performing sand fracturing by adopting a crack temporary plugging diverting agent B; adjusting the construction discharge capacity to 1-2m before adding a crack temporary plugging diverting agent after sand fracturing³The rotation speed of a sand mixing tank of the sand mixing truck is greater than 100r/min, the liquid level of the sand mixing tank does not exceed 2/3 scale marks, the temporary crack plugging diversion agent is prepared on site during adding, polyacrylamide serving as a raw material is continuously added during adding, the raw materials of other temporary crack plugging diversion agents are sequentially added within 1-2min, and after the addition is finished, the construction discharge capacity is increased to 4-6m³And min, after the construction pressure rises until the pressure is broken, adjusting the construction discharge capacity to the designed discharge capacity.

Preferably, the application in the temporary plugging diversion sand adding fracturing process is the same as the process of performing sand adding fracturing by adopting the fracture temporary plugging diversion agent A and the process of performing sand adding fracturing by adopting the fracture temporary plugging diversion agent B, and the process comprises the following steps:

(1) pumping the pad fluid;

(2) pumping sand carrying liquid;

(3) pumping a crack temporary plugging steering agent;

(4) pumping the pad fluid;

(5) pumping sand carrying liquid;

(6) pumping a crack temporary plugging steering agent;

(7) pumping the pad fluid;

(8) pumping sand carrying liquid;

(9) pumping displacement liquid: displacing the displacement fluid by 1.1 times of the volume of the well bore;

(10) closing the well for 2-24 h, starting to control open flow, and finishing the sand adding fracturing process after flowback is finished;

wherein, the liquid consumption of the pad fluid in the steps (1), (4) and (7) accounts for 30 percent of the total pad fluid: 30%: 40 percent; the proportion of the sand adding amount of the sand-carrying liquid in the steps (2), (5) and (8) to the total sand adding amount is 25%: 25%: 50 percent.

Preferably, the dosage of the crack temporary plugging diversion agent in the step (3) accounts for 0.3-0.8% of the total amount of the pad fluid and the sand-carrying fluid in the steps (1) and (2); the dosage of the crack temporary plugging diverter in the step (6) is the same as that of the crack temporary plugging diverter in the step (3).

Preferably, in the application of the temporary plugging diversion sand fracturing process, the process for performing sand fracturing by using the fracture temporary plugging diversion agent C comprises the following steps:

(1c) pumping the pad fluid;

(2c) pumping sand carrying liquid;

(3c) pumping a crack temporary plugging steering agent;

(4c) pumping the pad fluid;

(5c) pumping sand carrying liquid;

(6c) pumping sand carrying liquid;

(7c) pumping displacement liquid: displacing the displacement fluid by 1.1 times of the volume of the well bore;

(8c) closing the well for 2-24 h, starting to control open flow by adopting oil nozzles of 3mm, 5mm and 8mm, and finishing the sand fracturing process after flowback is finished;

wherein, the liquid consumption of the pad fluid in the steps (1 c) and (4 c) accounts for 60 percent of the total pad fluid: 40%, the proportion of the sand adding amount of the sand-carrying liquid in the steps (2 c) and (5 c) to the total sand adding amount is 70%: 30 percent.

Preferably, the amount of the fracture temporary plugging diversion agent in the step (3 c) is 0.3-0.8% of the total amount of the pad fluid and the sand-carrying fluid in the steps (1 c) and (2 c).

The crushing is an instant reduction in pressure.

The adding proportion of the sand carrying liquid in each step is not required, and each step is only required to ensure that the adding of the total sand carrying liquid is finished.

The pad fluid, the sand carrying fluid and the displacing fluid in the prior art can be used for realizing the invention, and the pad fluid, the sand carrying fluid and the displacing fluid which are suitable for the well in the prior art are selected for different wells.

The invention has the advantages that:

(1) the invention adopts polymer materials with better water solubility, designs a blocking mode of 'instant bridge blocking', quickly forms a pressure-resistant blocking wall by the mutual combination of three polymers with different particle diameters, realizes the opening of cracks in other dessert areas, and further increases the reconstruction volume of the cracks;

(2) compared with the conventional temporary plugging mode, the temporary plugging device has the characteristics of quick plugging, stability and easy dissolution.