井—震拟合反演压力系数技术及应用  

Logging and seismic fitting inversion pressure coefficient technology and its application

作　　者：张兆辉[1] 姚军[2] 苏明军[2] 

机构地区：[1]甘肃省油气资源研究重点实验室/中国科学院油气资源研究重点实验室,甘肃兰州730000 [2]中国石油勘探开发研究院西北分院,甘肃兰州730020

出　　处：《天然气地球科学》2016年第4期739-744,共6页Natural Gas Geoscience

基　　金：中国石油天然气股份公司"歧口富油气凹陷大油气田勘探与综合配套技术研究"项目(编号:2008-030504)资助

摘　　要：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,seismic,logging,empirical formulas and numerical simulation are mainly prediction methods for sand and silt section formation pressure,but the application is seriously challenged due to the methodological limitations and complexity exploration targets.Based on the analysis of common methods＇ principle,the＂fit well seismic inversion＂predicting method was proposed,it gives full play to longitudinal advantages of logging method and continuous lateral research strengths of seismic method.Implementation process mainly consists of three research steps：Firstly,use equivalent depth technique to compute well pressure coefficient profile and fit mathematical mappings between pressure coefficient of formation and logging impedance from acoustic and density curve;secondly,carry out lithology inversion of impedance and strip out mudstone impedance data;thirdly,convert mudstone data to pressure coefficient data from mathematical mappings above by nonlinear method,further obtain vertical and horizontal distribution of coefficient.Through multiple measurement points verification at Qibei low slope of Bohai Bay Basin,the results confirm that the inversion results error is small and the precision is high,which demonstrates a good prospect.It should be noted that the method only in upper-abnormal pressure formation has been confirmed,need to further confirm in lower-abnormal pressure formation,and it does not apply to the normal pressure formation for predicting pressure.

关 键 词：测井资料 波阻抗 压力系数 拟合反演 

分 类 号：TE271[石油与天然气工程—油气井工程]