An integral water plugging string suitable for plugging of shale gas horizontal wells

Abstract

The invention discloses an integral water plugging string suitable for plugging of shale gas horizontal wells. The lowermost end of the seat aid is connected with the drillable packer through the setting pusher and the soluble centralizing sleeve, and a hand-discharging mechanism is provided in the cylindrical structure formed by the setting pusher and the soluble centralizing sleeve. The upper end of the mechanism is connected to the center pipe of the seat aid, and the lower end is connected to the drillable packer. When the soluble centralizing sleeve and the soluble plugging core are dissolved, the seat aid and the packer can be separated by hydraulic pressure. . The pipe string of the present invention has high temperature and pressure resistance performance, and can realize hydraulic setting, sealing, blocking, and water blocking production by using one trip of the pipe string. When releasing, the hydraulic pressure is lost first, and the small-diameter seat aid is taken out, and then the drilling and milling is relatively short and easy to drill. The packer restores the original diameter of the casing, is safe and reliable to use, and improves the construction efficiency.

Description

technical field [0001] The invention relates to a water plugging pipe string for shale gas development, in particular to an integral water plugging pipe string suitable for the plugging of shale gas horizontal wells. Background technique [0002] For the upper water outlet of shale gas horizontal wells, the pipe string is used for water plugging, that is, the oil pipe is connected to the permanent packer and sealed below the water outlet section, and the oil pipe is used as the production channel. However, in view of the current relatively low international oil and gas prices, seeking lower-cost, efficient and risky pipe strings is the main direction for domestic oil companies to consider. The use of mechanical setting can no longer be satisfied. At present, the main strings for water plugging of gas production wells at home and abroad are: 1. The tubing is connected to the seat aid and the permanent packer to run to the design depth. Then run into the string with intubatio...

AI Technical Summary

Problems solved by technology

These two hydraulic permanent packers are not suitable for shale gas horizontal wells: 1. Shale gas wells are usually operated under pressure rather than under pressure. For example, in the first operation mode, the two strings do not have pressure up The lower cost is no more than 300,000. If the belt is used for lifting, the cost of one trip is more than 2 million, and the cost of two trips is close to 5 million. For this cost, oil companies are very difficult to be satisfied

2. The second type of tubing string that is set and stuck in one trip, the hydraulic piston is located below the rubber sleeve slips, and the permanent packers use integral slips and a reliable anti-shoulder mechanism. The thrust requires a lot of force. Check the information. At present, there are single-stage pistons and multi-stage piston mechanisms in the market. The single-stage piston may occupy more inner diameters to increase the piston area. Salvage is required, and the construction risk is relatively high

It is relatively difficult to salvage objects with irregular fish tops and non-rotating objects in the horizontal section

In addition, the intubation adopts the rotary buckle release method, which is not conducive to the operation under pressure in the horizontal section.

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