Supercritical carbon dioxide jetting stream well drilling device for exploiting hydrate

Abstract

The invention discloses a supercritical carbon dioxide jet drilling device for mining hydrates, belonging to the technical field of hydrate drilling equipment and technology, using supercritical carbon dioxide without water phase as drilling fluid to spray hydrate reservoirs Jet drilling will not cause the re-formation of a large amount of gas hydrate and reduce the production of gas hydrate reservoirs, and the temperature of the carbon dioxide jet will drop sharply due to the existence of the Joule-Thomson effect during the jetting process, which will not be like The rapid decomposition and release of hydrates caused by conventional drilling fluids is beneficial to prevent the occurrence of natural gas hydrate blowout accidents, and the carbon dioxide remaining in the hydrate reservoir after drilling can efficiently replace the natural gas in the hydrate reservoir, forming carbon dioxide Hydrates, whose thermodynamic characteristics are more stable than gas hydrates, can maintain sediment integrity and geomechanical stability.

Description

technical field [0001] The invention relates to the technical field of hydrate drilling equipment and technology, in particular to a supercritical carbon dioxide jet drilling device used for hydrate mining. Background technique [0002] With the rapid development of the global economy, the demand for resources is increasing day by day, and the demand for fossil energy, known as one of the three major energy sources, is even tighter. Seeking an economical and effective way to develop fossil energy has become the theme of current energy development. Research has found that the world's total fossil energy reserves are about 1.5-2.4 trillion tons, of which 40% are natural gas hydrates. The world's major oil and gas companies have taken the research on gas hydrate exploitation technology and resource utilization as a major development strategy. [0003] Among them, natural gas hydrate (Natural Gas Hydrate, referred to as Gas Hydrate), that is, combustible ice, is an ice-like cry...

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Problems solved by technology

[0004] Currently, natural gas is extracted from gas hydrates using standard techniques used in conventional oil and gas extraction, namely, reservoir depressurization, thermal stimulation, and injection of hydrate inhibitors, resulting in the decomposition of gas hydrates However, the drilling fluid used in the drilling process of the above method contains water phase. When drilling into the hydrate reservoir, the water in the pore space of the hydrate deposit can easily form hydrate again with the decomposed natural gas, preventing Cut off the decomposition path of gas, resulting in reduced production of hydrate reservoirs and reduced ultimate recovery

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