西湖1井钻前地震压力预测

PRE-DRILLING PREDICTION OF FORMATION PRESSURE IN WELL XIHU-1

西湖1井是准噶尔盆地南缘深部地层进一步油气勘探研究提供基础资料而部署的一口风险预探井。该井钻探构造高陡,钻遇断裂多,地层变化大,钻前地层压力预测更为重要。在地震地质解释研究的基础上,综合分析了工区内已钻的异常压力分布情况和形成机理,确定了本区地层压力的经验公式。通过对地震速度研究,建立三维速度场,进行层速度反演,提取井点地震速度。正确地估算了西湖1井的地层压力,为井身结构工程设计提供了依据,确保了钻井的顺利,地层压力预测结果与完钻后地层压力测试一致。

Xihu-1 well l is a deep and risk exploration well in the south margin of Junggar basin and it can provide a basis for further research on oil and gas exploration data in this area.The formation has high and steep structure and fracture.Before drilling,formation pressure prediction is even more important.In the study of seismic geological interpretation on the basis of comprehensive analysis of the wells drilled,the distribution and formation mechanism of abnormal pressure have been gotten,and it was determined the empirical formula of formation pressure in this area.Based on the study of seismic velocity,three dimensional velocity field has been setup,the interval velocity is inverted,and well seismic velocity is extracted.Correctly estimating of the well Xihu 1 formation pressure,casing design and ensure smooth drilling are made.The formation pressure prediction results has been consistent to the forrmation pressure testing results when drilling.