Horizontal well fracturing method for promoting multi-cluster cracking through repeated acid injection and temporary plugging

A horizontal well and acid injection technology, applied in the field of fracturing, can solve the problem that the perforation clusters are difficult to be simultaneously depressurized

Active Publication Date: 2021-02-09
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problem that the perforation clusters are difficult to be simultaneously depressed in the existing horizontal well multi-cluster fracturing, the present invention proposes a horizontal well staged fracturing A fracturing method that promotes multi-cluster fracture initiation during fracturing. This method can greatly increase the proportion of multi-perforation cluster fracture simultaneous opening, reduce the difficulty of multi-cluster simultaneous fracture initiation in the section, and thus help to achieve uniform and sufficient fractures in the sweet spot area. Improve the efficiency of staged multi-cluster fracturing in horizontal wells, and greatly increase the productivity of single wells

Method used

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  • Horizontal well fracturing method for promoting multi-cluster cracking through repeated acid injection and temporary plugging

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0071] A shale gas well has a vertical depth of 2198m, a sounding depth of 4385m, and a horizontal section length of 1565m. Follow the steps below to retrofit:

[0072] (1) Coiled tubing is used to carry a perforating gun to complete the first stage of perforating operation. Among them, the perforations are arranged in a spiral manner, the perforation length is 3m in total, the perforation density is 16 holes / m, the number of perforation clusters is 6 clusters, and there are 48 perforation holes in total;

[0073] After the first section of perforation operation, with 1m 3 A total of 10m of pretreatment acid is injected per minute 3 . then at 4m 3 The displacement per minute injects 45m of low-viscosity slippery water 3 For acid. Subsequent reduction in displacement to 1m 3 / min inject low viscosity slippery water 5m 3 Replace acid to increase acid rock reaction time.

[0074] Final injection 50m 3 High-viscosity glue 40mPa.s makes the main seam.

[0075] (2) Inject...

Embodiment 2

[0090] A shale gas well has a vertical depth of 2375m, a sounding depth of 4500m, and a horizontal section length of 1726m. Follow the steps below to retrofit:

[0091] (1) Coiled tubing is used to carry a perforating gun to complete the first stage of perforating operation. Among them, the perforations are arranged in a spiral manner, the perforation length is 3m in total, the perforation density is 16 holes / m, the number of perforation clusters is 6 clusters, and there are 48 perforation holes in total;

[0092] After the first section of perforation operation, with 1m 3 A total of 10m of pretreatment acid is injected per minute 3 . then at 4m 3 The displacement per minute injects 45m of low-viscosity slippery water 3 For acid. Subsequent reduction in displacement to 1m 3 / min inject low viscosity slippery water 5m 3 Replace acid to increase acid rock reaction time.

[0093] Final injection 50m 3 High-viscosity glue 45mPa.s makes the main seam.

[0094] (2) Inject...

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Abstract

The invention relates to a horizontal well fracturing method for promoting multi-cluster cracking through repeated acid injection and temporary plugging. The horizontal well fracturing method comprises the following steps that (1) fracturing fluid is injected optionally to make a main fracture; (2) fracturing fluid carrying carbonate rock particles with the mixed particle size is injected; (3) fracturing fluid is injected to make a new fracture; (4) the step (2) to the step (3) are repeated for a plurality of times till all perforation clusters are cracked and plugged successfully; (5) variable-viscosity acid liquor is injected; (6) fracturing construction is conducted; (7) a bridge plug is inserted; and (8) the step (1) to the step (7) are repeated till all sections are constructed, and plug drilling, flowback, testing and production seeking are conducted after fracturing. According to the horizontal well fracturing method, the carbonate rock particles with the mixed particle size arecyclically used for plugging the cracked perforation clusters for a plurality of times, balanced cracking and synchronous expanding of multi-cluster fractures are promoted, and the fracturing transformation efficiency is greatly improved; and variable-viscosity thickening acid is adopted for plugging, synchronous dissolving of the carbonate rock particles at fracture seams of all the perforationclusters is facilitated, the situation that a pump is stopped independently to wait for operation is avoided, and thus the construction efficiency is greatly improved.

Description

technical field [0001] The present invention relates to the field of fracturing, in particular to a horizontal well staged multi-cluster fracturing technology, in particular to a reservoir reconstruction method for promoting the initiation of multi-cluster fracturing fractures under the condition of horizontal well staged multi-cluster fracturing . Background technique [0002] At present, staged multi-cluster fracturing of horizontal wells has been widely used in the development of tight oil and gas, carbonate reservoirs, shale oil and gas, and coalbed methane. economic development benefits. [0003] However, the indoor core physical simulation experiment and field monitoring results show that due to the influence of reservoir heterogeneity and anisotropy, the fracture initiation pressure and extension pressure of each perforation cluster are quite different under the condition of multi-cluster fracturing in horizontal wells. , it is difficult for each perforation cluster...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E21B43/26E21B43/267E21B43/27E21B33/13
CPCE21B43/261E21B43/267E21B43/26E21B33/13
Inventor 蒋廷学仲冠宇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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