METHOD FOR HEATING OIL SHALE SUBSURFACE IN-SITU

摘要

Disclosed is a method for heating oil shale subsurface in-situ. The method may used to obtain shale oil and fuel gas from an underground oil shale layer in-situ, and may used to obtain fuel gas from underground coal bed in-situ. The method is as follows: Drilling wells (1) are drilled downwardly from the ground surface, and the depth of the wells reaches the working areas of the underground oil shale seam (2); drilling at least two wells and putting electrodes (3) in the wells; first, applying a high voltage that is enough to make the oil shale seam discharge partially to the electrodes, thus forming a plasma channel (6) resulting from the breakdown of the high electricity in the oil shale seam; after the resistance between the two electrode areas is reduced, a current is conducted into the plasma channel in the oil shale seam through the two electrodes; the oil shale seam is heated through the resistance heating function of the plasma channel, and the heat released is used to realize pyrolysis and gasification in given organic carbon of the oil shale seam. The method can improve the speed of underground seam heating process without applying hydraulic fracturing to the rock formations and avoid the use of toxic conductive material.