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A low -damage well pressure fluid and configuration method for low -pressure air wells

A technology for killing fluids and gas wells, which is applied in the directions of chemical instruments and methods, drilling compositions, etc., and can solve the problem of incapable of preventing a large amount of well-killing fluid filtration loss, aggravating scaling and blockage in the near-wellbore zone, reservoir protection and productivity damage. and other problems, to achieve the effect of reducing water lock damage, reducing gas intrusion, and reducing the pressure of the net liquid column

Active Publication Date: 2022-04-01
BC P INC CHINA NAT PETROLEUM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, it is not suitable for low-pressure gas wells, because low-pressure gas wells in low-permeability reservoirs have undergone fracturing in the early stage, and the pressure coefficient of some gas wells is as low as 0.2-0.4. A large amount of well fluid is lost. Due to the extremely low formation pressure coefficient, the foaming agent in the killing fluid alone cannot satisfy the flowback of the killing fluid.
The killing fluid cannot remove the scale and blockage near the wellbore in the early stage, and the additional introduction of well fluid with other salinities will aggravate the scale and blockage near the wellbore
When the polymer or starch fluid loss reducer produces a filter cake on the fracture wall and reaches the plugging pressure balance, the risk of gas channeling is high, which will cause great damage and decline to the reservoir protection and productivity of low-pressure gas wells in the later stage, and even bring The risk of no production after the low-pressure gas well is killed

Method used

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  • A low -damage well pressure fluid and configuration method for low -pressure air wells
  • A low -damage well pressure fluid and configuration method for low -pressure air wells
  • A low -damage well pressure fluid and configuration method for low -pressure air wells

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] A low-damage killing fluid used in low-pressure gas wells, the composition of which is as follows: degradable temporary plugging particles: 10-20%; carrier fluid: 4-6%; release agent: 3-5% ; the rest is water.

[0047] Described water can select the industrial water that meets national standard for use.

[0048] A configuration method for a low-damage well killing fluid used in a low-pressure gas well comprises the following steps:

[0049] Step 1: Add all the water in the mixing tank of the ground sand mixer, first add the formula amount of release agent, and stir for 5 minutes at a stirring rate of 100r / min;

[0050] Step 2: On the basis of Step 1, add the carrier liquid of the formula, control the stirring rate of 60r / min, and stir for 2min;

[0051] Step 3: On the basis of Step 2, after stirring for 2 minutes, slowly add the degradable temporary blocking particles of the formula, keep the stirring speed of 100r / min, and stir for 3 minutes;

[0052] Step 4: On the...

Embodiment 2

[0055] Compared with Example 1, the difference of this example is that the degradable temporary blocking particles, based on the weight percentage of the particles themselves, include the following components:

[0056] Main agent: 45-65%;

[0057] Adjuvant: 15-25%;

[0058] Cross-linking agent: 5-10%;

[0059] Degradation accelerator: 5-10%;

[0060] Antioxidant: 4-6%;

[0061] Curing agent: 4-6%;

[0062] Initiator: 2-4%.

[0063] Described main agent, by weight percentage, comprises following components:

[0064] Polyethyl methacrylate is calculated as 40-50%;

[0065] Acrylonitrile-methyl acrylate copolymer is calculated as 10-15%;

[0066] Polyethylene glycol diacrylate is calculated as 40-45%;

[0067] The molecular weight of the polyethylene glycol diacrylate is 6000-8000.

[0068] The molar ratio of acrylonitrile monomer to methyl acrylate monomer in the acrylonitrile-methyl acrylate copolymer is 2:5.

[0069] The auxiliary agent is: 2-hydroxyl-1,4-naphthoquin...

Embodiment 3

[0083] A low-injury killing fluid used in low-pressure gas wells, including: 10% degradable temporary plugging particles, 3% tallow amine polyoxyethylene ether, 1% tallow dihydroxyethyl betaine, 2% by weight percentage % sulfamic acid, 3% glycolic acid, 81% water;

[0084] Degradable temporary plugging particles, based on the weight percentage of the particles themselves, include the following components:

[0085] Main ingredient: 50%;

[0086] Adjuvant: 20%;

[0087] Cross-linking agent: 8%;

[0088] Degradation accelerator: 8%;

[0089] Antioxidant 5%;

[0090] Curing agent 5%;

[0091] Initiator: 4%;

[0092] The main agent, by weight percentage, has the following components:

[0093] Polyethyl methacrylate: 50%;

[0094] Acrylonitrile-methyl acrylate copolymer: 10%;

[0095] Polyethylene glycol diacrylate: 40%;

[0096] The low-damage killing fluid configuration method includes the following steps

[0097] Step 1: Add all the water into the mixing tank of the gr...

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Abstract

The present invention relates to the field of low-pressure gas well stimulation and reservoir protection technologies, in particular to a low-damage well killing fluid used in low-pressure gas wells and a configuration method. The components are: degradable temporary plugging particles in weight percentage: 10‑20%; carrier fluid: 4‑6%; release agent: 3‑5%; the rest is water. Adopting the present invention can realize low-pressure gas well killing operations with low damage. The liquid phase in the killing fluid can carry solid phase particles through the increase of viscosity, reduce liquid fluid loss, and clean the organic and inorganic blockages near the wellbore at the same time, and the solid phase in the killing fluid The particles form a high-strength, strong plugging body through the combination of bridges and self-bonding, and self-degrade after the well killing operation is completed. The low-damage killing fluid can improve the efficiency of workover operations, reduce the filtration loss of the killing fluid, improve the permeability of the reservoir near the wellbore, and achieve the purpose of increasing the production of low-pressure gas wells with low-damage killing operations.

Description

[0001] Technical field [0002] The invention relates to the technical field of production stimulation transformation and reservoir protection of low-pressure gas wells, in particular to a low-damage killing fluid used in low-pressure gas wells and a configuration method. Background technique [0003] During the production and development process of gas wells, with the production of natural gas, the energy in the near-wellbore area slowly decreases, and the bound water in the formation changes into a flowing state due to the pressure reduction. The formation water is produced with natural gas, and the formation energy decreases so that such wells become low-pressure gas wells. Low-pressure gas wells still have high industrial value after rational development. At present, secondary workover measures are mainly taken for low-pressure gas wells to increase single well productivity. The main problem faced in the workover process is how to control damage workover. [0004] During ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09K8/528C09K8/512
CPCC09K8/528C09K8/5083C09K8/5086C09K8/512
Inventor 蒋文学万向辉李勇吴增智郑维师陈平金娜王坤谭欢黄永章武月荣王玉功柴巧玲李珊尹虎琛徐方向诗佳庆李雪
Owner BC P INC CHINA NAT PETROLEUM CORP