Safe combustible ice mining method in seabed shallow layer

Abstract

The invention provides a safe combustible ice mining system and method in a seabed shallow layer. The safe combustible ice mining method comprises the following steps that a pre-development section isdetermined; the development program of combustible ice is developed; a row of 5-6 horizontal well sets are distributed; drilling is performed in the positions of the horizontal well sets; slotting treatment is performed around a shaft after drilling; pulling out of hole of a drill is performed; the completion fluid in the shaft is replaced; vapour with temperature being 120DEG C-180DEG C and pressure being 20MPa-30MPa is injected into separated wells in the 5-6 horizontal well sets; the water mist in the ejected gas is observed; ignition is performed; and the wellhead gas is incorporated intoa gas outlet pipeline. According to the features such as seabed topography and geomorphology, engineering geological characteristics, and a combustible ice reservoir in the hydrate area, the environmental problems and disasters caused by methane leakage are avoided from engineering through reasonable well location layout and pressure lowering schemes.

Description

technical field [0001] The invention relates to a system and method for safe mining of combustible ice in the shallow seabed, especially a system and method for overall development, reasonable pressure control, constant monitoring, orderly slowing down of seabed subsidence, and prevention of seabed depressions, landslides, tsunamis, and seawater poisoning in mining areas. Comprehensive supporting development technology for disasters and other disasters. The technical field belongs to the field of exploitation of marine oil and gas resources. Background technique [0002] Combustible ice is a solid substance mixed with water and natural gas. The main distribution areas of seabed gas hydrates in the world are the Gulf of Mexico in the Atlantic Ocean, the Caribbean Sea, the eastern continental margin of South America, the western continental margin of Africa and the eastern United States. The development of the Black Sea Platform off the coast is very difficult and risky, and ...

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Problems solved by technology

[0009] In order to overcome the existing methane leakage, which may cause geological disasters such as submarine landslides, or even cause environmental problems caused by methane leakage into the ocean or the atmosphere, the present invention provides a system and method for safe mining of combustible ice in the shallow seabed. Well arrangement mode of the group, optimization of drilling and completion mode, interval mining production system

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