Method for building bushing perforation fracturing-type artificial natural gas migration passage between gas reservoirs

Abstract

The invention discloses a method for building a bushing perforation fracturing-type artificial natural gas migration passage between gas reservoirs, and the method is characterized by comprising the following steps of selecting a gas reservoir to be developed; building a construction well; forming an uncased hole between the selected gas reservoir to be developed and a production gas reservoir of a developed gas field; loading a bushing into the uncased hole on two gas reservoir well sections; utilizing cement for well cementing of an annular well section between the uncased hole and the loaded bushing; forming a perforation hole on the reservoir well section of the bushing well section by utilizing a perforation gun; fracturing a reservoir section in the two gas reservoir storage layer well sections after the perforation of the bushing well section to form a fracturing crack; and setting a bridge plug above or in front of the two gas reservoir well sections to seal, so that the migration passage is formed. By adopting the development method, the migration passage is conveniently built between the reservoir sands of the production gas reservoir of the developed gas field and the selected gas reservoir to be developed, and economy and efficiency in development of the selected gas reservoir to be developed inside or surrounding the developed offshore gas field can be realized.

Description

technical field [0001] The invention relates to a method for developing natural gas, in particular to a method for establishing casing perforation and fracturing artificial migration channels between gas reservoirs. Background technique [0002] In or around the developed gas fields in the western South China Sea, there are many small-scale gas reservoirs, abnormally high-pressure gas reservoirs, low-permeability gas reservoirs and high CO content 2 The gas reservoir has not been put into development yet, and its overall reserves are large. Because among the above four gas pools to be developed selected by the present invention, small-scale gas pool development has less recoverable gas volume and offshore drilling and completion investment is relatively high; abnormally high pressure gas pool development has high safety requirements and low permeability gas pools Low production capacity requires drilling more wells and reforming reservoirs, high CO content 2 The develo...

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Problems solved by technology

[0005] 1) Drilling and development of new production platforms or underwater production systems. From the construction of new production platforms or underwater production systems to production, the cycle is long and the investment is large. It is difficult to realize the small-scale development in or around the offshore developed gas fields Gas reservoirs or abnormally high pressure gas reservoirs or low permeability gas reservoirs or high CO content 2 The economical and effective development of gas reservoirs will also cause the existing well pattern and existing production facilities of the developed gas field production platform or subsea production system to be unusable

[0006] 2) There are no remaining well slots on the production platform of the developed gas field or no remaining underwater wellheads in the underwater production system, and it is impossible to add well slots or increase underwater wellheads, or directly drill from the established production platform or underwater production system due to the development When economic and technical reasons cannot be realized, the selected small-scale gas reservoirs to be developed or abnormally high-pressure gas reservoirs or low-permeability gas reservoirs or high CO content 2 The reserves of gas reservoirs will not be developed, and the country's precious natural gas resources will be wasted

[0008]4) The development of abnormally high-pressure gas reservoirs and high CO2 gas reservoirs requires very high pressure safety levels and anti-corrosion requirements for relevant materials. High, resulting in a substantial increase in investment in drilling and completion and production facilities, seriously affecting economic benefits

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