基于井下解码器的EGS合采技术

Study on EGS co-mining technology based on downhole decoder

增强型地热系统(EGS)多层合采技术中,由于各储层进井压力差异显著,同井筒多储层合采作业中依然会出现较大的层间干扰现象,导致热产量较低且无法精确控制。以构造低产量多层位换热层合采作业为基础,结合井下解码器技术设计三管线控制六层位的EGS优化合采模型,通过管线与译码组合设计实现控制工质入流面积与压力来解决层间干扰与产量优化问题。结果表明利用解码器技术控制第二层滑套,工质总产量达到最大值为977 m^(3)/d,相对于无解码器工况下提高5.2%,通过该技术控制层位流量进行工质合采,可保证工质采收产量,同时可以避免由于单层流量大造成层间干扰等问题。

In the multi-layer combined production technology of enhanced geothermal system,due to the significant difference of inlet pressure of each reservoir,the large interlayer interference still occurs during the combined production of multi-reservoirs in the same wellbore,which leads to the result that the thermal output is low and cannot be accurately controlled.Based on the combined production of the multi-level heat exchange layer with low yield,in combination with the optimized EGS co-production model for the downhole decoder with three pipelines controlling six layers,the inflow area and pressure of the working fluid were controlled through the combined design of pipeline and decoding,in order to solve the problems of interlayer interference and output optimization.The results show that utilizing the decoder technology to control the second layer sliding sleeve,the total output of working fluid reaches the maximum value of 977 m^(3)/d,which is 5.2%higher than that without decoder.This shows that the technology can control the flow rate of layers to combine working fluid and ensure the production of working fluid,while avoiding the interlayer flow caused by the large single layer flow.