Multi-stage refracturing method for casing horizontal well

Abstract

The invention provides a casing horizontal well multi-segment refracturing method. The method is used for refracturing a horizontal well comprising multiple segments and includes the steps that temporary plugging rubber plugs are determined according to the gel breaking requirement of each segment; a plugging string capable of being dragged is lowered into the horizontal well; the temporary plugging rubber plugs corresponding to each segment are adopted to plug previous perforations left after previous fracturing construction; the first plugged segment of the horizontal well is perforated in an oriented mode again, and refracturing construction is carried out; operations are carried out on all the segments from the second to the M of the horizontal well and include lowering a perforation bridge plug combining string, setting a bridge plug, reorienting perforations and pulling out the string, conducting refracturing construction, wherein the first segment is the segment farthest away from a well opening, and the M segment is the segment closest to the well opening; all the bridge plugs are removed through drilling after fracturing, after all the bridge plugs are removed through drilling, gel breaking and hydration are carried out on the temporary plugging rubber plugs, and then the temporary plugging rubber plugs are returned and discharged.

Description

technical field [0001] The invention relates to the technical field of hydraulic fracturing of oil and gas reservoirs, and more particularly relates to a multi-stage repeated fracturing method for a casing horizontal well. Background technique [0002] Re-fracturing refers to the re-fracturing of wells that have been subjected to one or more fracturing measures. According to the practice of refracturing at home and abroad, refracturing has experienced the development and practice of three fracturing methods: new fractures in the layer, extension of existing fractures, and refracturing technology; in recent years, refracturing technology It has been further developed and widely used. [0003] The diverted refracturing technology uses special high-strength fracture temporary plugging materials to completely plug the artificial fractures generated by the initial fracturing. After the temporary plugging materials are pumped into the well, they selectively enter and plug the art...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to propose a multi-stage refracturing method for casing horizontal wells, which solves the problems of high risk of dragging pipe strings, easy failure of tools, and limited construction displacement and sanding volume in multi-stage refracturing of horizontal wells. Due to problems such as limitations, difficulty in increasing construction scale, limited volume of fracturing stimulation, and limited effect of fracturing stimulation stimulation, a new idea is proposed for repeated staged fracturing of casing horizontal wells, making it suitable for reservoirs such as shale The needs of large-scale fracturing construction

[0010] Various aspects of the present invention solve the problems of limited displacement and limited fracturing scale in multi-stage repeated fracturing of casing horizontal wells, greatly reduce pipeline friction during construction, reduce wellhead pressure, and increase sand adding scale and construction The efficiency ensures the construction effect of large-scale fracturing such as shale gas, and solves many problems such as the high risk of dragging the pipe string and the easy failure of tools and pipe strings in the current horizontal well refracturing; after the drilling plug is completed, The rubber plugs of all blocked previous holes will be completely broken and hydrated and discharged from the holes, ensuring that the productivity of the original previous fractures will not be affected after refracturing; refracturing of horizontal wells is like the well’s Like the first fracturing construction, perforation, bridge plugging, and fracturing construction can be carried out step by step for each section, which simplifies the construction process and is easy to implement, shortens the fracturing construction time, reduces the construction difficulty and risk, and improves the construction efficiency. Construction efficiency ensures the success of casing horizontal well refracturing construction, and the construction process cost is relatively low, which helps to reduce costs and increase efficiency, ensuring better economic benefits

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