Gas well production string provided with double parallel pipes

Abstract

The invention discloses a gas well production string provided with double parallel pipes. The gas well production string comprises a casing pipe, a double-pipe mandrel hanger, a large oil pipe, a small oil pipe and a double-pipe packer, wherein the large oil pipe and the small oil pipe are suspended in the casing pipe through the double-pipe mandrel hanger, and the double-pipe packer is used for packing the casing pipe and fixing the large oil pipe and the small oil pipe; a first underground safety valve and a first working barrel are mounted on the large oil pipe; a second underground safety valve and a second working barrel are mounted on the small oil pipe. When the initial productivity of the string is higher, the large oil pipe and the small oil pipe can be used for production simultaneously; when the mid-term productivity is reduced, the large oil pipe independently is used for production; after water breakthrough of a gas well, the liquid carrying capability of the small oil pipe is higher, and independent liquid carrying production can be performed; if more liquids are accumulated and blow-in cannot be realized, gas lift drainage gas recovery is adopted; the string is not required to be moved for operation in the whole production process of the gas well, the gas well production string has the characteristics of high gas producing rate and small environment pollution, later well repairing is not required, reservoir stratum pollution is reduced, the operation cost is reduced, and the string has good adaptability for high-yield gas field development.

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, and the patent name is a patent for a high-pressure gas well production and wax removal and prevention integrated pipe string. The utility model discloses a high-pressure gas well production and cleaning and prevention. The wax-integrated string structure includes setting a chemical agent injection valve on the oil pipe, which 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. In the middle of the valve, the other end protrudes to the ground, which can meet the conditions of protective fluid and packer in the annulus of high-pressure gas wells, and achieve the purpose of...

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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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