页岩气储层孔隙压力测井预测新方法

发布时间：2019-01-28 12:13

【摘要】：页岩气储层中常出现明显的异常高压现象,其孔隙压力会在短距离内大幅上升。若不能及时准确预测这些异常高压值,可能导致井涌、井喷等钻井事故,不仅会给钻井施工造成重大损失,还严重影响储层评价工作。然而,现有的方法却很难准确预测页岩气储层中的异常孔隙压力值。结合页岩气岩心实验数据,在充分考虑孔隙度、有机质含量和有效应力对声波速度影响的基础上,提出了一套基于声波速度模型的页岩气储层孔隙压力预测新方法。该方法通过使用不含气层段的纵波、横波速度关系对储层纵波速度进行含气性校正,消除了气体对异常高压现象在声波测井信息表征上的影响。此外,该方法还能预测因不平衡压实和生烃作用等多种机理引发的页岩气储层异常孔隙压力,弥补了现有传统方法只能预测由不平衡压实引起异常高压的不足。以昭通地区页岩地层S井为例进行储层孔隙压力预测,形成了基于声波速度模型的储层孔隙压力预测方法技术流程。
[Abstract]:Abnormal high pressure often occurs in shale gas reservoir, and pore pressure will rise significantly in short distance. If these abnormal high pressure values can not be predicted in time and accurately, it may lead to well bore, well blowout and other drilling accidents, which will not only cause great losses to drilling operation, but also seriously affect reservoir evaluation work. However, the existing methods are difficult to accurately predict the abnormal pore pressure in shale gas reservoirs. Based on the experimental data of shale gas core and considering the effects of porosity, organic matter content and effective stress on acoustic velocity, a new method for predicting pore pressure of shale gas reservoir based on acoustic velocity model is proposed. By using the compressional wave and the shear wave velocity relation without gas layer to correct the gas-bearing velocity of the reservoir, the influence of gas on the abnormal high pressure phenomenon on the characterization of acoustic logging information is eliminated. In addition, this method can predict the abnormal pore pressure of shale gas reservoir caused by unbalance compaction and hydrocarbon generation mechanism, which makes up for the deficiency that the traditional method can only predict abnormal high pressure caused by unbalanced compaction. Taking S well of shale formation in Zhaotong area as an example, the pore pressure prediction method based on acoustic velocity model has been developed.
【作者单位】：中国石油大学地球科学与技术学院;重庆科技学院复杂油气田勘探开发重庆市重点实验室;
【基金】：国家自然科学基金青年科学基金项目(No.41402118) 国家重大科技专项(2016ZX05006-002-004)资助
【分类号】：P631.81;TE311

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