Method for maintaining flow conductivity of seams near wellbore area

A near-wellbore zone, conductivity technology, applied in chemical instruments and methods, production fluids, earthwork drilling, etc., can solve problems such as affecting production, failure to form seepage channels, affecting fracture conductivity, etc., to improve plugging effect, risk reduction effect

Active Publication Date: 2016-06-08
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] 1. After the existing temporary plugging agent is degraded, there is no proppant support, and the fractures near the wellbore are closed, which affects the conductivity of the fractures and cannot form a seepage channel, which affects the production
[0006] 2. The particle size of the existing temporary plugging agent is uniform and the plugging effect is not good
[0007] 3. The existing degradable temporary plugging agents are mainly mixed particles made of bio-glue, modified asphalt, bone glue and / or gelatin, vegetable glue or their derivatives, etc., but the temporary plugging agents involved in these three patents will be degraded. The formation of residues consolidates in the fractures to block the seepage channels, so that the construction wells need to be put into production after 1-2 weeks or longer

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] In order to overcome the problems existing in the prior art, this embodiment provides a method for maintaining the fracture conductivity in the near-wellbore zone in the mine field, including the following steps:

[0029] 1) First determine the working fluid for temporary plugging diversion, which includes: by volume percentage, 17% degradable temporary plugging agent, 17% proppant and 66% low-viscosity carrier fluid, according to Young’s Modulus to determine the particle size combination of degradable temporary plugging agent, when Young's modulus is less than 25000MPa, all use large particle size degradable temporary plugging agent, when Young's modulus is 25000-30000MPa, small particle size can be used The degradable temporary plugging agent accounts for 70%, and the degradable temporary plugging agent with large particle size accounts for 30%. 70%;

[0030] 2) For staged fracturing, the pumping sequence is pre-fluid→sand-carrying fluid→temporary plugging and divert...

Embodiment 2

[0035] On the basis of Example 1, this example provides a method for maintaining the flow conductivity of multi-fracture fracturing openings in a horizontal well section. The particle size range of the degradable temporary plugging agent is 0.1-10mm, and the small particle size can The particle size range of the degradable temporary plugging agent is 0.1-1mm, and the particle size range of the large particle size degradable temporary plugging agent is 1-10mm. The degradable temporary plugging agent is composed of multi-scale (particle size 0.1-10mm) temporary blocking particles mixed in a certain proportion The degradable temporary plugging agent with a large particle size of 1-10mm is blocked at the crack port, and the small particle size of 0.1-1mm is filled between the degradable temporary plugging agent with a large particle size, which can effectively and quickly improve the plugging effect. The mixing ratio is based on The reservoir characteristics of different gas fields...

Embodiment 3

[0038] This embodiment provides a method for mines to maintain the conductivity of fractures in the near-wellbore zone, including the following steps:

[0039] 1) First determine the working fluid for temporary plugging diversion, which includes: by volume percentage, 17% degradable temporary plugging agent, 17% proppant and 66% low-viscosity carrier fluid, according to Young’s Modulus to determine the particle size combination of degradable temporary plugging agent, when Young's modulus is less than 25000MPa, all use large particle size degradable temporary plugging agent, when Young's modulus is 25000-30000MPa, small particle size can be used The degradable temporary plugging agent accounts for 70%, and the degradable temporary plugging agent with large particle size accounts for 30%. 70%;

[0040] 2) For staged fracturing, the pumping sequence is pre-fluid→sand-carrying fluid→temporary plugging and diverting working fluid. / section, the large particle size degradable tempo...

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Abstract

The invention provides a method for maintaining flow conductivity of seams near the wellbore area. The method comprises the steps of firstly, preparing a temporary plugging steering working solution, wherein the temporary plugging steering working solution comprises degradable temporary plugging agents, an equidensity proppant and a low-viscosity carrying liquid; carrying out staged fracturing, wherein the pump injection sequence is a prepad fluid, a sand-carrying fluid and the temporary plugging steering working solution; and after complete fracturing, waiting till the temporary plugging steering working solution is degraded, carrying out fluid drainage, and ensuring that the proppant remains at the seams and forms a seepage channel. According to the method, the degradable temporary plugging agents are formed through mixing multi-scale combined degradable temporary plugging agents according to a certain proportion, the large-particle degradable temporary plugging agents are blocked at the end openings of the seams, and the clearances among the large-particle degradable temporary plugging agents are filled with the small-particle degradable temporary plugging agents, so that the plugging effect is effectively and quickly improved, after fracturing, the degradable temporary plugging agents and the proppant exist in the hydraulic fracture seams, after the degradable temporary plugging agents are degraded, the proppant maintains the flow conductivity of a near mineshaft, the risk that the seams near the wellbore area are closed and do not have the flow conductivity is reduced, and seepage channels of a gas reservoir and a mineshaft are maintained.

Description

technical field [0001] The invention relates to the field of staged transformation of low-permeability gas reservoirs, in particular to a method for maintaining fracture conductivity in near-wellbore zones in mines. Background technique [0002] Fracture conductivity is defined as the product of permeability and fracture propped width at the closure pressure of the reservoir. The function of the proppant is to keep the fracture open after pump injection stops and flowback. The performance of the proppant directly affects the long-term conductivity of the fracture. [0003] Temporary plugging multi-fracture fracturing technology is to add an appropriate amount of temporary plugging agent to the formation in a timely manner during the construction process, and follow the principle of flowing in the direction of the least resistance. The diverting agent enters the original fracture or high permeability layer with the fracturing fluid. Under the action of pressure difference, h...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E21B43/26E21B43/267E21B33/13C09K8/508
CPCC09K8/5083C09K2208/26E21B33/13E21B43/26E21B43/267
Inventor 郝瑞芬赵振峰李宪文马旭叶亮张燕明来轩昂古永红周长静王亚娟马占国何明舫毕曼胡杨明史华丁勇高伟
Owner PETROCHINA CO LTD
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