A multi-branch hydrate displacement mining method

Abstract

The invention discloses a multi-branch gas hydrate replacement mining method. By drilling and producing production wells in the horizontal direction in the hydrate reservoir, repeated consumption of a large amount of resources to penetrate the dense overlying layer of the hydrate is avoided, and the initial mining is utilized. The depressurization method is used to reduce the pressure of the horizontal production well, and then use the replacement material to fracturing the horizontal production well and suppress the pressure of the well, so that the replacement material can fully contact and react with the hydrate, and at the same time deflect in the same layer of the horizontal production well. The next horizontal production well can be drilled at the position or the upper layer, and hydrate production can be carried out at other positions while the replacement operation is realized, so that the production and replacement can be carried out at the same time, saving the time and cost required for the replacement operation, so that the vertical depth and plane direction can be multiplied. All layer and branch wells can exist at the same time, and the combination form of branch wells is not limited. It only needs to fully consider the thickness and range of the hydrate reservoir to be exploited, geological characteristics, drilling and production process safety and other factors to effectively realize the hydrate formation of the entire reservoir. replacement mining.

Description

technical field [0001] The invention relates to the technical field of hydrate mining, in particular to a multi-branch hydrate replacement mining method. Background technique [0002] Hydrate is a clathrate unit cell compound formed by natural gas water under low temperature and high pressure environment, which is mainly distributed in terrestrial permafrost and seabed sediments. The current hydrate production methods mainly include depressurization method, heat injection method, chemical inhibitor injection method, displacement method and solid-state fluidization method. Among them, the depressurization method controls the decomposition efficiency of hydrate by adjusting the pressure. The expensive excitation process is recognized as the most economical mining method at present; the heat injection method increases the temperature of the reservoir by injecting heat to heat the formation, and then realizes the decomposition of hydrates, but the thermal conductivity is very lo...

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Problems solved by technology

[0005] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a multi-branch hydrate displacement production method, which can solve the problem of high cost, limited single well productivity and easy large-scale formation instability in the existing hydrate production method. And other issues

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