1. Content Overview
CRUSH technology first blasts and fractures the oil shale layer to increase the surface area of ??contact between CO2 and kerogen, and introduces CO2 from the vertical well in a convection manner. , heating the oil shale layer through a series of horizontal fractures. The generated hydrocarbon gas is produced through vertical wells.
EGL technology mainly uses the principles of convection and reflux heat transfer to heat oil shale formations, and is mainly composed of a heating system and an oil production system. The heating system is a closed loop system, mainly composed of several parallel horizontal wells. High-temperature natural gas or propane or retort gas is introduced into the annular system to bring in heat to heat the oil shale layer. Vertical wells are mainly used to collect oil and gas generated by pyrolysis and transport them to the surface.
Air heating technology first passes compressed air and retort gas into the burner for combustion, heats it to a certain temperature, consumes part of the oxygen, and then passes it into the oil shale formation to heat the oil shale to make it Organic matter generates hydrocarbon gas, and finally the generated hydrocarbon gas is brought to the ground. The produced hydrocarbon gas is condensed to obtain light oil.
IGE technical process: first inject high-temperature steam into the oil shale formation, convectively heat the oil shale, and after exchanging heat with the oil shale, displace the oil and gas generated by pyrolysis to the ground, condense, and Recycle. The separated uncondensed gas is heated to a certain temperature and then passed into the formation to exchange heat with the oil shale for recycling.
II. Application scope and application examples
The American Chevron Company and Los Alamos National Laboratory jointly developed CRUSH technology, and based on its design, it contains 2 to 5 four-dimensional Industrial test model of point well network unit for laboratory indoor experiments and small-scale field tests.
EGL technology was developed and patented by the American EGL Company. It is currently in the small-scale experimental stage and has not been commercialized on a large scale.
The high-temperature compressed air introduced by the air heating technology of the American Petro Probe company can fracture oil shale in the formation. There are four products: hydrogen, methane, light oil, and water; they are less polluting and environmentally friendly; Deep oil shale deposits (up to 900 m deep) can be developed; the oil shale after mining can still maintain 94% to 99% of the original structural integrity, avoiding ground collapse.
The American MWE company uses IGE technology to achieve economic benefits when developing in Green River oil shale formations that are more than 150 m deep and 8 m thick. In this process, the coverage area of ??one well can reach 3000 m2, and the oil production exceeds 8100 t/a.
3. Data sources
Liu Dexun, Wang Hongyan, Zheng Dewen, etc. 2009. Progress in world oil shale in-situ mining technology. Natural Gas Industry, 29(5): 128～132
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