Well completion method for standing column well enhanced geothermal system

Abstract

The invention relates to a well completion method for a standing column well enhanced geothermal system. The method is characterized in that a surface casing, an ordinary technical casing, a high temperature resistant technical casing, an oil tube, perforated holes and a high temperature resistant centralizer are included. By adoption of the well completion method for the standing column well enhanced geothermal system, deep-stratum geothermal energy can be effectively transmitted to the ground, and the specific achieving process is as follows: water is injected into an annulus space formed by the ordinary technical casing and the oil tube from the ground, the water in the annulus space flows from the upper portion to the lower portion, when flowing into the bottom of the annulus space, water flows from the perforated holes into the oil tube, and then the water in the oil tube flows from the lower portion to the upper portion and finally flows into a ground receiving device. The temperature of a geothermal reservoir is 200 DEG C or above, reservoir heat is transmitted to the annulus space formed by the high temperature resistant casing and the oil tube through the high temperature resistant technical casing, water flowing through the annulus space absorbs heat in the annulus space formed by the high temperature resistant technical casing and the oil tube, the temperature of the water is increased after the water absorbs the heat, and then high-temperature water flows through the oil tube to the ground receiving device for electric generation.

Description

technical field [0001] The invention relates to the technical field of geothermal exploitation, in particular to a single well circulation enhanced geothermal system well completion method. Background technique [0002] The continuous development of non-renewable conventional energy sources (oil, natural gas and coal, etc.) and the resource and environmental problems brought about by the development are becoming more and more serious. However, geothermal resources have entered our field of vision as a clean, low-carbon, safe and efficient renewable energy. . Geothermal energy is mainly divided into hydrothermal geothermal energy and dry-hot rock-type geothermal energy. At present, the mining and utilization of geothermal resources in the world is mainly hydrothermal-type geothermal energy. However, the exploitation and utilization of dry-hot rock-type geothermal energy has broad prospects. Hot dry rock type geothermal means that the underground reservoir is high-temperature...

AI Technical Summary

Problems solved by technology

However, there are several deficiencies in this system: (1) the system needs to drill two wells, and the cost of each geothermal well needs at least 10 million yuan, which is expensive and increases the development cost; (2) after drilling two wells, it needs For fracturing, the cost of 1000m long fracturing is about 6 million. The cost of fracturing is expensive, which increases the development cost

Based on the above analysis, the development cost of hot dry rock type geothermal energy is high, so it is urgent for us to develop a technology that can exploit geothermal energy by drilling only one well without fracturing, so as to reduce the cost of hot dry rock type geothermal energy. Development costs

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