基于地震的探井钻前孔隙压力预测20150422要点解析.pdfVIP

基于地震资料的探井钻前孔隙压力预测 陈鑫，魏小东，李艳静，夏亚良，周晓明 (东方地球物理公司研究院，河北 涿州 072750 ；） 摘要：钻前压力预测在保障钻井安全、选取合理的钻井液密度、设计科学的井身结构、降低钻井成本和保 护油气层方面都具有十分重要的意义。由于地震资料的多解性，压力预测的精度常常达不到钻井的要求。 本次研究以伊拉克西南部的 A 油田为研究区，针对该区探井深层资料少和地震响应复杂的两个难点，以地 震资料为基础，充分结合区域地质和浅层测井资料，从压力预测的成因研究出发，优选压力预测方法，开 展井震联合上覆孔隙压力预测、地质一致性精细速度解释和地震速度变化率分段求取等一系列工作，成功 预测出了深层探井的孔隙压力。经钻井验证，压力预测成果与实测结果的相对误差小于 3%，该方法能够大 幅度提高钻前孔隙压力预测的精度。 关键词：孔隙压力；地震-地质-测井联合，钻前预测；深层探井 。 Pore pressure prediction based on seismic data for exploration well before drilling Chen Xin, Wei Xiao-dong, Cao Lai-sheng, Li Yan-jing , Xia Ya-liang, Zhou Xiao-ming （Geophysical Research Institue, BGP, Zhuozhou Hebei,072750） Abstract ：Pore pressure prediction before drilling is significant on ensuring drilling safety, reasonable drilling mud density, designing well profile and it can also reduce the drilling cost and protect the hydrocarbon reservoir. The accuracy of pressure prediction usually cannot meet the drilling requirement due to multi solutions of seismic data. This paper focuses on A oilfield which is located in southwest of Iraq. There is no exploration well data in deep layer and the seismic response is complicated. Forcing on these two difficulties, based on the seismic data, integrated with regional geological and shallow well logging data, started with the mechanisms that cause formation pressure, optimized the pressure prediction methods, we carry out the overburden pressure prediction, seismic velocity analysis based on geological consistency, and variation rate of seismic velocity estimation. The deep formation pressure of exploration well was predicted successfully. The prediction result accuracy error is less than 3% compared with the measured data which is test