鲁北砂岩热储地热尾水回灌试验研究

Lubei geothermal tail water reinjection experiments in sandstone reservoir

摘要:

山东省鲁北平原蕴藏有丰富的地热资源，目前得到广泛开发利用的热储为新近纪馆陶组热储与古近纪东营组热储，热储类型为沉积盆地型碎屑岩孔隙—裂隙热储，天然状态下，该类热储中的地热流体基本上处于静止状态，补给极其微弱，地热流体的大量开采造成了热储压力的急剧下降，回灌成为了维持热储压力的必要措施。针对该类热储，国内外进行了大量的回灌试验研究，总体回灌效果不佳，并将原因归结于回灌时热储的堵塞。该文在分析研究区内多次回灌试验成果的基础上，提出了砂岩热储回灌的不同机理，认为合理地布置开采井与回灌井之间的距离，促使开采井与回灌井之间形成水力循环，是解决砂岩热储中回灌难问题的关键。

Abstract:

There are abundant of geothermal resources buried under LuBei plain in Shandong. The widely developed and utilized geothermal reservoirs are Guantao group and Dongyin group of clastic sedimentary porefracture type geothermal reservoirs. Under natural conditions, the geothermal fluid in the reservoir largely dormant, replenishment is extremely weak. Exploitation of geothermal fluid causing a sharp drop in the reservoir pressure, in that reinjection has become the necessary measures to maintain reservoir pressure. Aimed at this kind of clastic geothermal reservoir, there are a large number of reinjection experiments have been performed, but the overall reinjection effects are not optimistic. Researchers blamed the failure to reservoir blockage during reinjection. Based on the analysis of past reinjection experiment activities, the author puts forward three different mechanisms pertinent to reinjection in sandstone geothermal reservoir, and draws a conclusion that reasonable arrangement of the distance between production well and reinjection well, prompting hydraulic loop formed between production well and reinjection well is the key to solve the problem hampered reinjection in sandstone geothermal reservoir.