基于三维地震数据的地层压力预测方法研究

发布时间：2019-05-13 19:18

【摘要】：异常地层压力往往是钻井过程中的高风险因素。随着勘探目标的加深,更加需要一种方法来提高钻前地层压力的预测效果,从而提升钻井效率,缩短钻井周期、提前配置好合理的泥浆密度和减少钻井过程中井喷井漏等事故的发生。影响地层压力预测效果的因素主要有:(1)异常地层压力成因的地质认识;(2)地震速度求取的准确度;(3)未综合考虑岩石物性(如速度,密度和孔隙性)对地层压力的影响。新方法主要针对渤海H油田,实现了一种效果更好的井震结合的地层压力预测方法。具体步骤如下:(1)综合分析可知,研究区渤海H油田目的层沙三段的异常压力成因为:欠压实和有机质的生烃作用引起的流体膨胀。(2)由于井上实测压力值较少,约束效果欠佳。新方法先利用Eberhart-Phillips公式求取井上整个目的层段的压力值,以更好的利用井上数据来约束反演地层压力的三维数据体。Eberhart-Phillips公式的优点在于综合考虑了岩石物性(速度、孔隙度、泥质含量)对地层压力的影响;(3)利用测井数据,分别统计整井和目的层段的Gardner公式,并且计算其所对应的速度,分别称为背景速度和目的层速度。背景速度由井信息约束下的叠加速度转层速度得到。目的层速度由模拟退火法下的宽带约束反演的波阻抗和目的层的Gardner公式得到。背景速度可以较好的反映上覆地层压力的变化趋势,目的层速度则与岩性密切相关,可以提高地层压力的预测效果。(4)利用整井统计的Gardner公式,计算背景速度所对应的从地表到目的层的密度,再通过对密度进行积分,计算上覆地层压力。再将目的层速度代入改进的Fillippone公式中去,利用井上的地层压力值约束得到整个目的层段的三维地层压力数据,从而实现地层压力的准确预测。
[Abstract]:Abnormal formation pressure is often a high risk factor in drilling process. With the deepening of exploration targets, it is more necessary to improve the prediction effect of formation pressure before drilling, so as to improve drilling efficiency and shorten drilling cycle. Arrange reasonable mud density in advance and reduce the occurrence of blowout well leakage in drilling process. The main factors affecting the prediction effect of formation pressure are as follows: (1) the geological understanding of the origin of abnormal formation pressure, (2) the accuracy of seismic velocity calculation, and (2) the accuracy of seismic velocity calculation. (3) the influence of rock physical properties (such as velocity, density and porosity) on formation pressure is not considered comprehensively. The new method is mainly aimed at Bohai H Oilfield, and a better prediction method of formation pressure combined with well earthquake is realized. The specific steps are as follows: (1) Comprehensive analysis shows that the abnormal pressure in the third member of the target layer of Bohai H Oilfield in the study area is due to the fluid expansion caused by undercompaction and hydrocarbon generation of organic matter. (2) due to the small measured pressure value in the well, The constraint effect is not good. The new method first uses Eberhart-Phillips formula to calculate the pressure value of the whole target section of the well, in order to make better use of the well data to constrain the inversion of the three-dimensional data volume of formation pressure. The advantage of Eberhart-Phillips formula is that it takes into account the physical properties of rock (velocity). The influence of porosity and mud content on formation pressure; (3) using logging data, the Gardner formulas of the whole well and the target section are counted respectively, and the corresponding velocity is calculated, which is called background velocity and target layer velocity, respectively. The background velocity is obtained from the stacking velocity under the constraint of well information. The velocity of the target layer is obtained from the wave impedance of the broadband constrained inversion under the simulated annealing method and the Gardner formula of the target layer. The background velocity can better reflect the changing trend of overlying formation pressure, while the target layer velocity is closely related to lithology, which can improve the prediction effect of formation pressure. (4) the Gardner formula of whole well statistics is used. The density from the surface to the target layer corresponding to the background velocity is calculated, and then the overlying formation pressure is calculated by integrating the density. Then the velocity of the target layer is replaced by the improved Fillippone formula, and the three-dimensional formation pressure data of the whole target section are obtained by using the formation pressure value constraint on the well, so as to realize the accurate prediction of formation pressure.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P618.13

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