Construction tool and method for improving recovery ratio of horizontal well of low-permeability reservoir

Abstract

The invention belongs to the technical field of oil and gas development, and relates to a construction tool and method for improving the recovery ratio of a horizontal well of a low-permeability reservoir. The construction tool for improving the recovery ratio of the horizontal well of the low-permeability reservoir comprises a pipe column, wherein the pipe column comprises an outer wall and an inner wall; the lower end of the pipe column is connected with a drill bit; the pipe column internally comprises an upper sliding block, a sliding sleeve spring and a ball seat which are sequentially connected from top to bottom; the upper sliding block and the sliding sleeve spring are located in a closed space formed by the outer wall and the inner wall; a cavity is formed by the upper portion of the upper sliding block and the outer wall, a sliding hole is formed in the middle of the upper sliding block, and the lower portion of the upper sliding block is connected with the sliding sleeve spring; a lower contact block and a packer rubber sleeve are arranged outside the pipe column, the lower contact block is located in the cavity, and the packer rubber sleeve is connected with the contact block and located at the corresponding position outside the pipe column; a fixing hole is further formed in the outer wall; and an external light ball is further included. By means of the construction tool and method, the overall utilization degree and the recovery ratio of the low-permeability reservoir are improved.

Description

technical field [0001] The invention belongs to the technical field of oil and gas development, and relates to a construction tool and a method for improving the recovery rate of a horizontal well in a low-permeability oil reservoir. Background technique [0002] Horizontal wells are one of the key technologies for the development of low-permeability oil and gas fields at home and abroad. The number of horizontal wells is increasing year by year. However, with the continuous deepening of exploration and development of horizontal wells, the formation pressure of oil reservoirs gradually decreases, and the production of single wells decreases year by year. In order to solve this problem, major oil and gas fields have adopted various methods to increase formation pressure, such as water injection, gas injection, etc., but the effect is not obvious. Some horizontal wells have increased water content, channeling between injection wells and production wells, and even Flooding caus...

AI Technical Summary

Problems solved by technology

(1) The first method is water injection and gas injection. This method is to deploy special injection wells around horizontal wells and inject media according to the designed amount. However, low-permeability horizontal wells are basically put into production by large-scale fracturing. , a large number of artificial fracture networks are distributed around the horizontal section, and the injected medium can easily enter the horizontal wellbore along the fractures, resulting in an increase in the water (gas) content of the horizontal well, and even problems such as water (gas) channeling and shutting down the well.

(2) Another method is to increase the energy of the formation through the general huff and puff (water or gas) of the horizontal well itself. This method can only supplement the pressure of the low-pressure interval, and it is difficult to meet the differential energy supplement demand caused by the contradiction between horizontal intervals. The pertinence is not strong, and this method has very limited improvement in the overall pressure and production of horizontal well formations

Since the opening degree (length) of fracturing in each horizontal section is different, the position of the isolation tool must be fixed when running the string, which will cause a gap between the opening degree (length) and the position of the packer (interval). Differences, resulting in multiple tripping strings, increasing the construction period and cost

This method has more complex tool strings, higher construction risks, high operation requirements, and high construction costs.

Therefore, there are still many problems in the technical method of enhancing oil recovery by increasing the formation energy of low-permeability horizontal wells

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