Close cutting fracturing method

A fracturing and close technology, applied in the field of fracturing, can solve the problems of horizontal principal stress difference, increase construction pressure window, reduce displacement and construction pressure demand, etc., to achieve the demand of reducing displacement, reduce construction pressure and construction Difficulty, the effect of increasing the amount of liquid

Active Publication Date: 2021-01-05
CHINA PETROLEUM & CHEM CORP +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] In order to solve the problems existing in the existing deep shale gas fracturing, the present invention proposes a new fracturing method, through which the perforating gun is perforated twice to realize 1 to 2 clusters of fluids in a single section, reducing the The displacement and construction pressure requirements increase the construction pressure window; at the same time, using the stress shadow effect generated in the multi-cluster crack expansion, the horizontal principal stress difference is reduced, and the difficulty of crack network formation is reduced, so as to realize the narrow construction pressure window. Intensive cutting of sweet spot areas under certain conditions, thereby improving the reservoir stimulation effect of deep shale gas wells

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Embodiment 1

[0111] The shale gas well is located in the southwestern part of Sichuan, with a vertical depth of 4127m, a sounding depth of 6109m, and a horizontal section length of 1530m. The well has a relatively deep buried depth and high construction pressure. The method proposed by the present invention was used to stimulate the reservoir. For details, refer to the examples, wherein the evaluation of shale parameters and the optimization of fracturing parameters were carried out before the reconstruction.

[0112] (1) Two clusters of perforating operations close to target point B are performed by using the coiled tubing down-entry perforating gun;

[0113] (2) at 1.5m 3 A total of 20m of pretreatment acid is injected per minute 3 . then at 5m 3 / min displacement into high viscosity slippery water 60m 3 Replacing acid; displacement reduced to 1m 3 / min, then continue to inject high-viscosity liquid for 30m 3 , while the displacement quickly increased to 8m 3 / min;

[0114] (3) I...

Embodiment 2

[0136] The shale gas well is located in the southwestern part of Sichuan, with a vertical depth of 4250m, a sounding depth of 6278m, and a horizontal section length of 1435m. The well has a relatively deep buried depth and high construction pressure. The method proposed by the present invention was used to stimulate the reservoir. For details, refer to the examples, wherein the evaluation of shale parameters and the optimization of fracturing parameters were carried out before the reconstruction.

[0137] (1) Two clusters of perforating operations close to target point B are performed by using the coiled tubing down-entry perforating gun;

[0138] (2) by 1m 3 A total of 10m of pretreatment acid is injected per minute 3 . then at 3m 3 / min displacement into high viscosity slippery water 60m 3 Replacing acid; Displacement reduced to 0.8m 3 / min, then continue to inject high-viscosity liquid for 30m 3 , while the displacement quickly increased to 8m 3 / min;

[0139] (3) I...

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Abstract

The invention relates to a close cutting fracturing method. The method comprises the steps that shale parameters are evaluated, and fracture parameters and fracturing construction parameters are optimized; perforation operation of the first time is carried out; fracturing treatment is carried out, and a liquid rubber plug carrying a propping agent is injected after fracturing treatment is finished; displacement operation is carried out; perforation operation of the second time is carried out; fracturing treatment and displacement operation are carried out; ball throwing temporary plugging is carried out on transformed perforation clusters; fracturing treatment is carried out on perforation clusters which are not transformed; displacement operation is carried out; a bridge plug is tripped in, and the above steps are repeated until construction of all sections is completed; and plug drilling after pressing, flowback, testing and production are carried out. 5-8 clusters of high-difficultyoperation are converted into 3-stage fracturing operation through two times of perforation operation and ball throwing temporary plugging in a single section, and therefore conventional 3-6 clustersof the single section are reduced into 1-2 clusters of the single stage fracturing operation, the liquid inlet amount of a single cluster is increased, the requirement of fracturing construction for displacement is reduced, and a construction pressure window is enlarged; and meanwhile, the horizontal principal stress difference is reduced through the stress shadow effect, the fracture complexity is improved, and the transformation size of a deep shale gas well is increased.

Description

technical field [0001] The invention relates to the field of fracturing, in particular to a segmented multi-cluster fracturing technology for shale gas wells, in particular to a close-cut fracturing method suitable for deep shale gas wells. Background technique [0002] my country is rich in deep shale gas resources at a depth of 3500 m, accounting for more than 85% of shale gas resources. Therefore, the successful development of deep shale gas resources is of great significance for my country to further tap potential and increase reserves. Practice has proved that the close-cut fracturing process, that is, reducing the cluster spacing and increasing the number of fracturing clusters, is one of the important ways to realize the efficient development of deep shale gas. Taking North America as an example, from 2011 to 2017, the cluster spacing of Haynesville shale gas wells decreased from 15 to 24 m to 10 to 15 m; in the Eagle Ford shale oil and gas region, the average cluster...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E21B43/267E21B43/27
CPCE21B43/267E21B43/26
Inventor 仲冠宇蒋廷学王海涛李双明卞晓冰卫然苏瑗肖博左罗
Owner CHINA PETROLEUM & CHEM CORP
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