| Sandstone geothermal resources of middle-low temperature has its advantage of widely distributed, large reserves, production easily.however, extensive development and utilization in long time that led to decrease of reservoir pressure.This restricts the sustainable development of geothermal resources. Geothermal reinjection is important way to solve the heat reservoir pressure decline, realizing the sustainable utilization of geothermal resources. This paper reviews the development history of geothermal sandstone reinjection and development trend, discusses the new technology and new methods about Tianjin geothermal sandstone recharge, probes into the key issues to geothermal sandstone reinjection. Based on Neogene sandstone thermal reservoir lithology characteristics with further study, we get a new sense of new process and method of geothermal reinjection well completion under the geological structure characteristics of process and method, put forward suitable for different heat reservoir characteristics of well completion technology; And the construction of the demonstration project of Neogene geothermal reinjection was built applying the latest achievements in research and reinjection effect is very significant.The results show that:(1)Neogene geothermal reservoir in Tianjin region was pore type reservoir with mainly fluvial facies sedimentary, for normal consolidated formation, cement is given priority with argillaceous, calcium, silica, porous media pore development, but the pore throat size is very different, particle migration and deposition occurred in the interior of the pore and the inner surface, and the migration and deposition laws tend to have relationship with pore size distribution fractal dimension.(2) According to different heat reservoir characteristics, different well completion technology is used to improve the reinjection effect. It is of great significance.(3) Demonstration project of geothermal reinjection Well that its reinjection zone is Guantao group, reinjection test reflected that the maximum reinjection is114m3/h, natural recharge rate is about95%according corresponding production of120m3/h. Demonstration effect is remarkable. From the results of demonstration project of technology application, it can be seen that the reasonable process of design, ground equipment, and strictly observe operation rules on recharge integrated technology is the key to guarantee the Neogene sandstones recharge success or failure. |
PDF Full Text Request