摘要
松辽盆地白垩系大陆科学钻探松科2井设计井深达6 400m,是东亚地区最深的科学探井。松辽盆地地温梯度高,深层孔隙流体压力组成与分布十分复杂,因此准确预测地层温度和压力,对整个钻探工程至关重要。通过对松科2井井区探井测温、试油数据的整理分析,探索目的层地温、地温梯度、地层压力与深度规律,对井底温度进行预测,并对主要目的层地层压力和地层破裂压力进行分段预测。利用深度与地温关系、深度与地温梯度关系和深井对比等方法,综合预测6 400m井底温度为238.83~265.11℃。利用松科2井井区地层压力与深度关系,破裂压力系数平均值和DrillWorks软件计算结果,综合预测营城组、沙河子组、火石岭组-井底地层压力分别为30.54~37.72、33.22~59.52和59.52~67.18 MPa,地层破裂压力分别为52.35~58.62,61.88~105.68和104.57~118.03 MPa。
The designed depth of SK2 is 6400 m,which is the deepest scientific drilling in the East Asia.Previous studies shows that the Xujiaweizi Fault Depression is located in the high geotemperature area.However the high geotemperature and possible abnormal pressure are the main challenges for continental scientific drilling.Based on a great deal of geological and geophysical data including regional geological survey,petroleum exploration and exploitation and scientific achievements in the Songliao Basin,we predicted the bottom hole temperature,formation pressure and formation fracture pressure of target strata of SK2.According to the relationship between depth and present geotemperatures,geothermal gradients,we predicted the bottom hole geotemperature of SK2 probably range from 238.83 ℃ to 265.11 ℃.According to the relationship between depth and formation pressures,and calculated results using DrillWorks,we estimated the formation pressure of Yingcheng Formation,Shahezi Formation and Huoshiling Formation to the bottom of the hole in the range of 30.54-37.72 MPa,33.22-59.52 MPa,59.52-67.18 MPa,respectively;and the formation fracture pressure range from 52.35 MPa to 58.62 MPa,from 61.88 MPa to 105.68 MPa,from 104.57 MPa to 118.03 MPa,respectively.