Method for improving recovery efficiency of high-hydrocarbon-content gas deposit by high-CO2-content gas deposit

Abstract

The invention discloses a method for improving the recovery efficiency of a high-hydrocarbon-content gas deposit by a high-CO2-content gas deposit, natural gas in the high-CO2-content gas deposit is transported to a developed high-hydrocarbon-content gas deposit by building an artificial natural gas transportation channel between the high-CO2-content gas deposit and the developed high-hydrocarbon-content gas deposit and fully utilizing the stratum energy of the high-CO2-content gas deposit, so as to implement 'CO2 gas drive' to improve the recovery efficiency of natural gas of the developed high-hydrocarbon-content gas deposit. According to the method, an existing production platform or underwater production system is fully utilized to shorten the development period and reduce the investment cost. In addition, the CO2 removal cost is further lowered, the high-CO2-content natural gas is transported to the developed high-hydrocarbon-content gas deposit through the artificial transportation channel without being limited by the number of the production platforms or underwater wellheads; when the method is adopted to implement 'CO2 gas drive', the stratum energy of the high-CO2-content gas deposit is fully used for improving the stratum pressure of the high- hydrocarbon-content gas deposit and the recovery efficiency of the natural gas of the high- hydrocarbon-content gas deposit.

Description

technical field [0001] The invention relates to a method for developing natural gas, in particular to a method for improving the recovery rate of high hydrocarbon-containing gas reservoirs. Background technique [0002] High in CO 2 Gas reservoir refers to the CO in natural gas 2 Gas reservoirs with content >50%. Currently high in CO 2 CO produced during gas reservoir development and production 2 The treatment method of decarbonization and separation is mainly used to vent, which is costly and not fully utilized, thus causing some high CO content 2 Gas reservoirs with low producing degree or difficult to develop and utilize. In general, high-hydrocarbon gas reservoirs are mainly developed by depletion, and the main means to increase the natural gas recovery rate is to reduce the wellhead pressure by adding large-scale compressors; due to the high investment and operating costs of large-scale compressors, the development of offshore gas fields still needs to be expand...

AI Technical Summary

Problems solved by technology

[0004] 1) High CO content 2 The drilling and completion of gas reservoir development and development and production have high anti-corrosion requirements, and the investment costs of drilling and completion and production facilities are relatively high. 2 The cost is also higher;

[0005] 2) High CO content cannot be utilized 2 Formation energy of gas reservoirs to enhance the recovery of developed high hydrocarbon-bearing gas reservoirs;

[0006] 3) The cost of reducing wellhead pressure by adding large compressors is high, which makes the economic recovery rate of developed high hydrocarbon gas reservoirs low

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