摘要
碳酸盐岩组成复杂,储集层空间类型多,储层参数的规律性较差,AVO响应特征弱,尤其是孔隙形状对弹性参数的影响不可忽略.针对碳酸盐岩储层的特点,基于自洽模型和微分等效模型构建了多孔隙结构条件下多相介质的碳酸盐岩岩石物理模型.按照各相介质体积含量由小到大的顺序,先利用自洽模型计算孔隙度为50%时的双相等效介质,再通过微分等效模型将孔隙度调整至实际孔隙度,计算实际孔隙条件下的双相介质等效体,重复迭代该过程,最终构建出与实际岩石等效的介质体,计算获得等效岩石的弹性模量参数.通过实验对比了自洽模型、微分等效模型与自洽-微分等效模型的岩石弹性模量与孔隙度、孔隙纵横比之间的适用性规律.最后基于四川龙岗飞仙关组实际测井资料,结合自洽-微分等效模型进行了目标地层的横波预测.结果显示该模型的横波预测效果相对Xu-Payne模型预测,两者预测曲线比较接近,但在形态上更接近实际横波.SCA-DEM模型在孔隙度和孔隙纵横比上具有更好的适应性,为碳酸盐岩孔洞型储层的岩石物理建模提供了一种新参考.
Carbonate rock has complex compositions of mineral,and the reservoir has more spatial types.The regularity of the carbonate reservoir parameters is poor,and the response characteristics of AVO are weak,especially it cannot be ignored to the effect of the pore shape on the elastic parameters.According to the characteristics of carbonate reservoir,a rock model for carbonate in porous media has been built based on self-consistent approximation model and differential effective medium.The self-consistent approximation model is used for computing biphasic equivalent when the porosity is 50%,and then adjusted to the actual porosity with differential effective medium model.The final construction of the rock can be produced in repeating the iterative process according to the ascending order by volume ratios of the composed phases,and the equivalent elastic moduli of the rock can be also obtained.The availability of the elastic moduli on porosity and pore aspect ratio is contrasted with the self-consistent approximation model,the differential effective medium model and the combination model.Finally,the s-wave prediction of the target stratum is carried out by the combination model based on the logging data from Feixianguan Formation of Long-gang region in the Sichuan basin.The result shows that waveform predicted by the SCA-DEM model is closer to the actual s-wave compared to the Xu-Payne model.SCA-DEM model has better adaptability in porosity and pore aspect ratio,which provides a new reference for petrophysical modeling of carbonate porous reservoirs.
作者
曹晓初
常少英
李立胜
邵萌珠
王宗仁
王启迪
金弟
CAO Xiao-chu;CHANG Shao-ying;LI Li-sheng;SHAO Meng-zhu;WANG Zong-ren;WANG Qi-di;JIN Di(PetroChina Hangzhou Research Institute of Geology,Hangzhou 310023,China)
出处
《地球物理学进展》
CSCD
北大核心
2019年第6期2239-2246,共8页
Progress in Geophysics
基金
国家十三五国家重大专项(2016ZX05004-002)
中国石油天然气股份有限公司深层专项(2014E-32-02)联合资助
关键词
碳酸盐岩
自洽模型
微分等效模型
孔隙结构
介质等效体
Carbonate rocks
Self-consistent approximation model
Differential effective medium
Pore structure
Medium equivalent
