Time-delay sliding sleeve

Abstract

The invention discloses a time-delay sliding sleeve and belongs to the field of oilfield development. The time-delay sliding sleeve comprises a left joint, an outer cylinder, a right joint, an inner cylinder, a partition ring, a time-delay mechanism and a starting ring, wherein the left joint, the outer cylinder and the right joint are sequentially connected from left to right; the cylinder diameter of the left end of the inner cylinder is greater than that of the right end of the inner cylinder, and the inner cylinder is slidably arranged in the outer cylinder in a sleeved mode. The inner cylinder is connected with the starting ring, a sealed annular space is arranged between the inner cylinder and the outer cylinder, and the starting ring is used for being separated from the inner cylinder after the pressure reaches a preset value. A fracturing hole located in the left side of the annular space is formed in the side wall of the outer cylinder. Hydraulic oil is arranged in a right cavity, and the time-delay mechanism is used for controlling the flow of the hydraulic oil and real-time connecting and disconnecting of the right cavity and a left cavity. The time-delay sliding sleevecan meet the construction requirement of building of a first-section fracturing channel, and is easy to operate, short in operation period and low in cost, the communicating time between an inner cavity of the inner cylinder and the fracturing hole can be controlled precisely, and full-wellbore pressure test is achieved.

Description

technical field [0001] The invention relates to the field of unconventional oil and gas field development, in particular to a time-delay sliding sleeve. Background technique [0002] In the development of unconventional oil and gas reservoirs, in order to improve the flow environment of oil underground and increase the production of oil wells, it is generally necessary to perform staged fracturing operations. Before the fracturing operation, it is very important to establish the first fracturing channel in the oil and gas well. [0003] In the related art, before the fracturing operation, the coiled tubing is used to perforate the fracturing string or conventionally activate the sliding sleeve to establish the first fracturing channel in the oil and gas well. [0004] The inventor finds that the prior art has at least the following problems: [0005] If it is necessary to perform fracturing operations in deep horizontal wells, then perforating the fracturing string through...

AI Technical Summary

Problems solved by technology

[0005] If it is necessary to perform fracturing operations in deep horizontal wells, then perforating the fracturing string through coiled tubing to establish the first section of fracturing channels in oil and gas wells not only has a long period and high cost, but also is limited by the wellbore trajectory. and coiled tubing operation length limitation

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