潘庄凸起奥陶系地热井施工风险分析

Analysis on the Ordovician Geothermal Well Construction Risk in the Panzhuang Uplift

通过对潘庄凸起8眼奥陶系地热井钻井、测井资料分析研究,笔者认为在奥陶系顶部及亮甲山组—马家沟组之间分别发育两层古风化壳岩溶带,其中奥陶系顶部"潜山型"古风化壳岩溶溶洞、裂隙发育,连通性好,富水性强,是良好热储层,但钻井钻遇该处时易发生钻井液严重漏失,埋钻等事故。因此在该类地层钻井施工中除了及时仔细观察岩屑外,还要结合钻机运行状态注意钻进参数变化,做好地层综合判定工作,降低施工风险。

The author concluded that there are two old weathering crusts in Ordovician based on the research of 8 Ordovician geothermal drilling wells. One is in the top of the Ordovician, and the other is between the Liangjiashan and Majiagou layers. And the crust in the top of Ordovician is ＇Qianshan＇ type in which fissures developed well with good connectivity. It stores large quantity of water, and is a good heat storage layer. But it is easy to have drilling burying accident or serious leakage of drilling fluid during drilling. In order to reduce the risk of the construction, we should judge the layers accurately in the drilling process, not only observe the rock scraps carefully, but also combine with condition of the rig running.