【作者】 邵才瑞；

【导师】 印兴耀；

【作者基本信息】 中国石油大学 ， 地质资源与地质工程， 2008， 博士

【摘要】 横波速度是重要的测井物探联合反演标定参数,鉴于目前许多井缺乏横波速度资料、现有横波速度估算方法存在精度低、使用不便的困难,给出了更合理有效的波速等弹性参数估算方法。论文根据分析力学梳理了饱和流体孔隙介质的理论体系,比较了Biot模型和BISQ模型的差异,通过数值实验分析了不同相态组合条件下混合介质等效弹性参数估算方法的适用性,推导了饱和流体孔隙介质等效弹性参数与固-流两相弹性参数之间的关系。基于孔隙介质波动理论,分析了地层骨架矿物成分、孔隙大小、流体饱和度及波动频率等因素对波速的影响,比较了饱和流体孔隙介质不同速度模型的合理性。通过利用多元测井信息对储层进行多矿物和流体组分分析,选用VRH模型求取骨架颗粒和流体等效弹性模量,然后利用Biot-Gassmann方程、以纵波速度为约束条件估算横波速度。该方法物理意义明确,实际处理资料比较表明本文方法比著名的Xu-White模型更简便、经济和准确,估值平均相对误差限在5%左右,精度比Xu-White模型提高了一倍左右。煤系地层是油气勘探的重要目标之一。与Xu-White模型相比,上述多矿物分析波速估值方法虽然在煤层能得到更合理的估值,但由于煤层组分非常复杂,估值误差相对砂泥地层偏大。为此,通过对典型煤层测井响应特征和识别方法研究,利用多井资料建立了煤层纵横波之间,密度、中子和纵横波之间的回归模型,改善了多矿物分析方法对煤层波速估值误差较大的缺陷。通过建立煤层体积模型,给出了利用密度和中子测井资料求解煤层组分、利用双侧向资料迭代反演裂隙孔隙度的方法;根据碳分含量采用等温吸附方程给出了比经验公式更为合理的吸附气含量估算方法。最后,综合油气储层测井评价及多矿物分析弹性参数估算方法,设计了较完善的煤系地层评价流程,为煤系地层勘探提供了有效的地层组分、物性、流体性质及弹性参数定量计算方法和程序。通过对实际煤系地层测井资料的识别和处理,表明煤层具有显著的低速、低弹性模量和低波阻抗弹性特征,为煤系地层勘探提供了岩石物理基础。更多还原

【Abstract】 The shear wave velocity of well log is one important parameter for mutual inversion. As lots of wells short of this data and present method can’t estimate the shear velocity precisely, this thesis gives a more accurate shear velocity estimation method. The paper summarized the theories of elastic-wave propagation in fluid-saturated porous media according to the analytic mechanics, compared the differences between Biot model and BISQ model, analyzed the applicability of different effective elastic modulus estimation methods for different phase combination conditions through numerical experiments, deduced the relations between effective elastic parameters of fluid-saturated porous media and its solid and liquid phase composites. Based on elastic-wave propagation theories in fluid-saturated porous media and rock physics, the main influence factors of velocity in porous media, such as mineral components, porosity and liquid saturation has been analyzed, and the rationality of different velocity models are compared. The method estimates the solid and liquid composites effective elastic modulus using VRH model via multi-mineral analysis from conventional well logs, and then calculates the shear wave velocity using Biot-Gassmann equations controlled by compressional velocity. The method has definite physical meaning, practice results show that this method is much more facility, economy and precise compared to the famous Xu-White method, its average absolute relative error between estimated values and measured values is about 5 percents, which is only half of Xu-White method.Although above multi-mineral analysis method can obtain a more reasonable wave velocity compared with the Xu-White model in the coal bed, the error of estimated wave velocity is greater than that of non-coal zones as the coal has complex components. Therefore, through the typical coal bed log responses characteristics and recognition methods study, the regression models between density and velocity, neutron porosity and velocity, shear velocity and compressional velocity are given by multi-well logs statistical analysis, so the precision of estimated share wave velocity of coal bed is improved. Through the coal bed volume model establishment, the coal components are calculated by density and neutron well logs, the cranny porosity is calculated using iterative inversion method with dual laterologs, and the adsorbed gas content is given using temperature adsorption equation according to coal bed carbon content which is more reasonable than empirical formula. Finally, combined with the oil gas reservoir log evaluation technique and multi-mineral analysis velocity estimate method for non coal zones, a systemic quantificational evaluation procedure for coal measure strata is given, which can provide the zone components, porosity, permeability, liquid property and elastic parameters. The application results show that the coal zone has distinct low velocity, low elastic moduli and low elastic impedance aspects,which provides the rock physical foundation for coal measure strata exploration.更多还原