U-shaped well hydraulic jet fracturing method

Abstract

The invention relates to a hydraulic jet fracturing method for a U-shaped well. The method comprises the following steps: I, loading an oil pipe with a spray gun into a casing of a horizontal well, arranging a casing gate in an annular space between the oil pipe and the casing of the horizontal well, and arranging a draining gate in a casing of the straight well; II, closing the casing gate, opening the draining gate, perforating through the oil pipe under the condition of communication of the horizontal well and the straight well, opening the casing gate after perforation, injecting a fracturing base solution into the oil pipe and the casing of the horizontal well, and jacking perforation sand in the oil pipe onto the ground; III, closing the draining gate, fracturing the oil pipe and the casing, injecting sand carrying liquid into formation fracture through the oil pipe; IV, closing the draining gate, injecting active liquid into the oil pipe and the casing of the horizontal well to jack fracturing sand in the oil pipe onto the ground through the straight well in order to finish fracturing.

Description

technical field [0001] The invention relates to a U-shaped well fracturing method, in particular to a U-shaped well hydraulic jet fracturing method. Background technique [0002] In the field of oil and gas production, a U-shaped well usually consists of a directional horizontal well and a vertical well. The target end of the horizontal section of the horizontal well is connected to the vertical well, and the two wells form a roughly "U"-shaped structure, so they are called U-shaped wells. In the development of coalbed methane wells, the horizontal wells of U-shaped wells are used for pressure construction, while the vertical wells are used for drainage and decompression gas recovery and coal dust removal. In the design, U-shaped wells are generally arranged in the high part of the coal seam structure, vertical wells are arranged in the low part of the coal seam structure, and the screen completion method is generally used. [0003] The commonly used method for stimulation...

AI Technical Summary

Problems solved by technology

In horizontal wells completed with screens, the fluid can flow not only in the space between the fracturing string 5 and the screen 4, but also between the screen 4 and the open hole wall 2, so neither forward washing nor backwashing It is conducive to sand flushing, which can easily lead to sand stuck in the pipe string, making it impossible to complete the fracturing operation in the subsequent well section, affecting the fracturing effect and production

For the U-shaped well according to the prior art, because it uses a smaller size screen to complete the well, the space between the fracturing string and the screen is smaller, and the fluid flow resistance is greater, which further aggravates sand sticking Odds of strings that are difficult to reform with conventional hydrojet fracturing

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