摘要
灰岩地层纵波速度对地层压力变化敏感性较低,若采用传统针对砂泥岩地层的模型进行孔隙压力计算可能导致较大计算误差。伊朗Y油田上部地层主要为砂泥岩夹孔隙型灰岩地层,中下部为大段孔隙型灰岩地层。针对该油田孔隙型灰岩地层岩性、异常高压形成机制、地球物理响应特点,形成了一套孔隙型灰岩地层压力综合检测方法。对于中部具有泥岩夹层的灰岩地层,优选传统基于泥页岩沉积压实规律的计算方法;对于无法提取泥岩点的大段孔隙型灰岩地层,采用多元速度模型和有效应力定理进行检测。方法在Y油田20口井得到应用,检测精度达90%以上,为井身结构和钻井参数优化提供了重要地质参数。
Carbonates hold more than 60% of the world~ remaining oil. In carbonate formation, abnormal pore pressure generation mechanism and geophysical response to effective stress are different from those of sand/mud- stone formations, so applying traditional pore pressure calculation methods developed for sand/mudstone formation to carbonate formation may result in huge errors. In oilfield Y, a carbonate oilfield in the south west of Iran, the formation mainly contains porous limestone with little fractures, which makes it possible to calculate pore pressure by wireline logging data. According to the lithology, formation pressure generation mechanism and geophysical re- sponse character, Jianyi model was selected for shale-embedded limestone formation after comparison by field data, a comprehensive velocity model in which the effects of effective stress, shale content and porosity to acoustic veloci- ty were considered was developed for limestone formations in the bottom of the field where shale points cannot be picked up from wireline logging data. Finally, an integrated pore pressure calculation method for porous limestone in Oilfield Y was obtained 23 wells＇ formation pressure profiles were obtained by this method, and the calculation accuracy was more than 90%.
出处
《科学技术与工程》
北大核心
2013年第13期3584-3587,共4页
Science Technology and Engineering
基金
国家重大专项专题(2011ZX05031-004-001)资助
关键词
伊朗Y油田
孔隙型灰岩
地层压力
声波速度
有效应力
Oilfield Y porous limestone formation pressure acoustic velocity effective stress
