A concentric double-pipe gas well production string

Abstract

The invention discloses a concentric double-pipe gas well production pipe string, which includes a casing, a small oil pipe hanger, a small oil pipe cross, a large oil pipe hanger, an outer pipe string, a downhole safety valve, an inner pipe string, and an annulus downhole safety valve , double-tubular packer, small-diameter tubing nipple, small working barrel, single-tubular packer and large working barrel, the outer string is suspended in the casing through a large tubing hanger, and the single-tubular packer Packing, the large working cylinder is docked on the outer pipe string; the small oil pipe cross is set on the original cross at the top of the casing, the inner pipe string is set in the outer pipe string, and is hung on the small oil pipe cross through the small oil pipe hanger Above, the double-tube packer seals the outer pipe string, the small working cylinder is connected to the inner pipe string, the small-diameter tubing nipple is fixed on the double-pipe packer, and the annulus downhole safety valve is set on the small-diameter tubing short. At the upper end of the joint, the downhole safety valve is butted on the inner pipe string. The pipe string has the characteristics of fast gas recovery, no need for workover in the later stage, reduced operating costs, and less environmental pollution.

Description

technical field [0001] The invention relates to oil and gas exploitation equipment, in particular to a gas well production string. Background technique [0002] The State Intellectual Property Office published the publication number CN203452734U on February 26, 2014. The patent name is a patent for a high-pressure gas well production and wax removal and prevention integrated pipe string, which discloses a high-pressure gas well production and wax removal and prevention. Chemical pipe string structure, including setting a chemical agent injection valve on the oil pipe, the chemical agent injection valve is a one-way valve; in addition, a capillary line is set in the annulus between the oil pipe and the casing, and one end of the capillary line is connected to the chemical agent injection valve , the other end protrudes to the ground, which can meet the conditions of high-pressure gas well annulus with protective fluid and packer to achieve the purpose of wax removal; in addit...

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Problems solved by technology

[0003] The technical solution of the above-mentioned patent is obviously different from the technical solution of the present invention, and the problems to be solved are also different. Because the above-mentioned patent adopts the traditional single string Optimize the production string according to the production requirements, and the size of the string is only suitable for the production requirements when the production capacity is high in the initial stage of production

In the middle and later stages of gas well production, with the formation pressure drop, production layer pollution, water discharge and other problems, the original production string will not be able to meet the demand for liquid-carrying production, resulting in liquid accumulation or even water flooding and shutdown of gas wells

At this time, it is necessary to restore the normal production of the gas well by implementing drainage and gas recovery through workover operations. The workover operation of gas wells requires a large investment, high risk, and great difficulty. After the well, the expected goal cannot be achieved, which not only causes economic losses, but also causes environmental pollution.

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