Downhole complete set of equipment and method for staged fracturing and completion of branch wells

Abstract

The invention provides a branching well staged fracturing well completion underground complete equipment and method. The equipment comprises a positioning tool string or a branching well hole fracturing tool string. The positioning tool string comprises a drill pipe, an orientation pup joint and a positioning device which are detachably connected from top to bottom. The positioning device comprises a lowering system and a sealing base which are detachably connected from top to bottom. The lowering system comprises a connecting rod and a conical expansion plug which are arranged from top to bottom. The lower portion of the sealing base is fixedly connected with a screwed plug and comprises a sealing part and a containing part which are arranged from top to bottom, and the conical expansion plug is arranged in an inner cavity of the containing part. The containing part, the screwed plug and the conical expansion plug define a propelling cavity, and the propelling cavity propels the conical expansion plug to move upwards to squeeze the sealing part to expand in the radial direction. The branching well hole fracturing tool string comprises a drill pipe, a releasing tool and a branching well hole staged fracturing well completion pipe string which are detachably connected from top to bottom. By means of the equipment and the method, the fracturing pipe column string can be fed in place, and the fracturing safety is improved.

Description

technical field [0001] The invention relates to the technical field of drilling and completion in the petroleum and natural gas industry, in particular to a complete set of well completion downhole equipment and method for staged fracturing of branch wells. Background technique [0002] A multilateral well is a well in which several wellbores are drilled at different depths in one main wellbore to exploit oil layers at different depths. This technology can increase the drainage area, increase the production of oil wells, and reduce the cost of reservoir development in an all-round way. In low-porosity, low-permeability, low-pressure and heterogeneous oil and gas reservoirs, staged fracturing in lateral wellbore can effectively increase single well production. [0003] In the conventional technology, the fracturing tubing string is generally used to directly send the fracturing string into place before fracturing. Due to the light weight and low rigidity of the tubing string...

AI Technical Summary

Problems solved by technology

[0003] In the conventional technology, the fracturing tubing string is generally used to directly send the fracturing string into place before fracturing. Due to the light weight and low rigidity of the tubing string, it often occurs that the string cannot be sent in place in extended-reach horizontal wells, such as In the actual operation, after repeated feeding is still not in place, it is often directly fractured at the feeding position, which affects the fracturing effect and cannot significantly increase the single well production.

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