塔里木盆地山前复杂带钻井地层压力预测

地层压力的准确预测是钻井井身结构、泥浆性能和钻井参数设计的直接依据,其对优质高效安全钻井,减少井下复杂情况,保护油气层、固井、完井等意义重大。由于地质、地震资料及认识的局限性,难以对塔里木盆地山前探井准确预测钻前地层压力,从而影响钻井工程顺利实施。首先在地震资料钻前压力预测的基础上,及时利用中途测井资料,修正压力预测模型,调整模型参数,然后重新标定过井地震资料,建立地震与测井信息之间的非线性映射关系,预测未钻地层岩石物理信息,进而预测得到地层孔隙压力、坍塌压力、破裂压力等,为下步钻进参数优化调整提供参考依据。

Formation Pressure Prediction of Drilling into Complex Zones in Piedmont of Tarim Basin

The correct prediction of formation pressure as dirrect basis of drilling well bore structure,mud quality and drilling parameter design is of great significance to high quality,efficient and safety drilling,reducing downhole complex problem,preserving oil-gas zones,well cementation and completion.The piedmont of Tarim basin was of limitations of geology,seismic data and related knowledges,so the correct prediction of pre-drilling formation pressure was difficult,and the proper drilling engineering implementation was affected.This paper presents the method for proper prediction of strata pore pressure,collapse pressure and fracture pressure by using the pre-drilling formation pressure,drillstem test,corrected pressure prediction model,model parameter modulation,re-calibrating well-corrosing seismic data,establishing non-linear mapping relation and undrilled strata petrophysical information prediction,etc.in order to provide support bases for parameter’s optimization and regulation of next drilling process.