Shale gas horizontal well refracturing method

Abstract

The invention discloses a shale gas horizontal well refracturing method, which relates to the technical field of refracturing, and is characterized by comprising the following steps: S1, preparing a refracturing sleeve, and arranging packers at two ends of a refracturing interval; s2, the repeated fracturing casing pipe is put into a shaft; s3, plugging is conducted, temporary plugging liquid is conveyed in a circulating mode, temporary plugging is conducted on primary fracturing, the packer is plugged after temporary plugging, and reconstruction of the re-fracturing shaft is completed; and S4, re-fracturing is carried out, and re-fracturing is carried out on the re-fractured interval so as to generate a new crack. According to the method, the sealing performance of plugging of the primary perforation hole can be improved, the shale gas production shaft is reconstructed through the refracturing sleeve, the fracturing success rate is increased, refracturing cracks of all sections are independently treated, the effectiveness and accuracy of refracturing transformation are improved, the flowing direction of fracturing fluid is predicted more accurately, crack expansion is controlled more accurately, and the fracturing efficiency is improved. And the reservoir transformation volume is increased to the maximum extent.

Description

technical field [0001] The invention relates to the technical field of shale gas horizontal well fracturing, more specifically, it relates to a method for repeated fracturing of shale gas horizontal wells. Background technique [0002] Shale gas refers to unconventional natural gas deposited in organic-rich shale-dominated reservoir rock series, and is continuously generated biochemical or thermogenic gas or a mixture of the two. Shale gas acquisition is usually Using horizontal wells for fracturing to excavate shale gas in shale reservoirs. After a certain period of time after the first fracturing, the fractures close and the conductivity decreases step by step, resulting in a decrease in production. Repeated fracturing is required to restore or increase productivity. The traditional shale gas refracturing method basically adopts temporary plugging and refracturing technology, such as authorized announcement number or application publication number CN110761763B, CN11092491...

AI Technical Summary

Problems solved by technology

For the above repeated fracturing technology, when the temporary plugging ball or temporary plugging agent is added, due to the poor followability of the temporary plugging ball or temporary plugging agent in the liquid, the liquid inlet channel may not be blocked, resulting in liquid inflow The channel is over-reformed, and some fractures are over-extended, while other areas are not effectively restructured, resulting in poor sealing of the original fractures in the reconstructed wellbore, so that when re-fracturing, the pumped fracturing The direction of fluid flow is uncontrolled, and the ground cannot accurately know the fracturing interval. That is to say, due to insufficient sealing performance, it is impossible to accurately control the new repeated fracturing interval, which leads to blindness in fracturing construction and is difficult to maximize. Repeated transformation of the reservoir

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