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目前,预测地层压力的方法主要有地震法、测井法、经验公式法和数值模拟法,由于方法的局限性、勘探对象的日益复杂性,应用受到严重挑战。在常用预测方法原理分析的基础上,充分发挥测井法的纵向高分辨率和地震法的平面数据密集连续研究优势,提出“井—震拟合反演”法预测地层压力,实现过程主要包含3个研究步骤:1采用等效深度技术计算井点压力系数剖面,拟合出压力系数与测井波阻抗的数学映射关系;2开展基于波阻抗岩性反演,并且剥离出泥岩波阻抗数据体;3利用波阻抗与压力系数的数学映射关系将泥岩波阻抗数据体转换为压力系数数据体,进一步得到压力系数纵、横向分布特征。通过渤海湾盆地歧北低斜坡多口井多个实际测压点的验证,结果证实反演结果误差小、精度高,展示出良好的应用前景。值得注意的是,该方法目前仅在异常高压地层的压力预测中取得良好效果,而在异常低压地层中能否有效应用还需进一步证实,不适用于正常压实地层的压力预测。
At present, the methods of predicting formation pressure mainly include seismic method, logging method, empirical formula method and numerical simulation method. Due to the limitation of the method and the increasing complexity of the exploration target, the application is seriously challenged. On the basis of the principle analysis of common forecasting methods, this paper gives full play to the advantages of long-range vertical resolution of well logging method and dense continuous data of seismic data, and proposes that “well-seismic fitting inversion” method predict formation pressure and realize process There are mainly three research steps: 1 Calculating the well-point pressure coefficient profile by the equivalent depth technique and fitting the mathematical relationship between the pressure coefficient and the well impedance; 2 Carrying out lithological inversion based on wave impedance and stripping out the mudstone wave Impedance data body; 3 using the mathematical relationship between the impedance and the pressure coefficient mapping the mud impedance data volume body into the pressure coefficient data body, further pressure coefficient vertical and horizontal distribution characteristics. Through the verification of multiple actual pressure measurement points in the low-slope of Qifenbei in the Bohai Bay Basin, the results show that the error of inversion results is small and the precision is high, which shows a good application prospect. It is worth noting that this method is currently only effective in predicting the pressure of abnormally high pressure strata. However, the effective application in abnormally low pressure strata needs further confirmation and is not applicable to the pressure prediction in normal compacted strata.