地震岩石物理建模技术在迪北阿合组致密砂岩气中的应用  

Application of seismic rock physical modeling technology in tight sandstone gas of Dibei Ahe Formation

作　　者：陈强 彭盛强 赵光亮 皮学军 谭杨 王鑫 CHEN Qiang;PENG Shengqiang;ZHAO Guangliang;PI Xuejun;TAN Yang;WANG Xin(Petrochina Talim Oilfield Company,Geophysical Research Institute,Korla 841000,China;Beijing Aoyier Engineering Technology Co.,Ltd,Beijing 100000,China)

机构地区：[1]中国石油塔里木油田分公司勘探开发研究院地球物理所,库尔勒841000 [2]北京奥意尔工程技术有限公司,北京100000

出　　处：《物探化探计算技术》2024年第3期315-323,共9页Computing Techniques For Geophysical and Geochemical Exploration

摘　　要：塔里木盆地库车坳陷迪北地区侏罗系阿合组低孔低渗砂岩是迪北气田的主要储集层,石油地质条件优越,已有多口井的油气发现。由于本区阿合组砂岩裂缝较发育,储层孔隙结构复杂,孔速关系不单一,常规的单一砂岩孔隙结构的Xu-White岩石物理建模预测的横波精度较低。针对这一问题,笔者提出了砂岩变孔隙结构的Xu-white岩石物理建模方法,首先基于微分有效介质模型,对砂岩孔隙宽长比进行了正演模拟,建立了模拟结果与孔隙度的拟合关系得到砂岩孔隙结构曲线;然后利用砂岩变孔隙结构Xu-White岩石物理模型对阿合组地层进行弹性曲线正演,对比单一砂岩孔隙结构的正演结果,其模型预测精度有所改善;最后基于建模后测井曲线和岩石物理解释图版对阿合组致密气层进行了识别,建模后气层的弹性响应特征更明显,泊松比明显小于0.18,体积模量小于3.0×10^(4) MPa,同时建立了阿合组地震岩石物理图版,考察不同“干”岩石骨架下,不同流体饱和度条件下地层弹性响应的变化规律,基本框定了气层的弹性响应窗口,这为后续的地震储层和流体定量预测提供了可靠的理论依据。The low porosity and low permeability sandstone of Jurassic Ahe formation in the Dibei area of Kuqa depression in Tarim Basin is the main reservoir of the Dibei gas field.The petroleum geological conditions are superior,oil and gas have been observed in many wells.Due to fractures in the sandstone of Ahe formation in this area,the complex pore structure of the reservoir,no singular relationship between porosity and velocities,and the conventional Xu-White modeling with a single sandstone pore structure generally poor shear wave data.This article proposes a method based on the Xu-White modeling of sandstone with variable sand pore structure in response to this issue.Firstly,this paper conducts a forward simulation of the sandstone pore aspect ratio based on the differential effective medium model and calculates the sandstone aspect ratio curve using the fitting relationship between the simulation results and porosity.Then,based on the Xu-White modeling of sandstone with variable sand pore structure,elastic curves of Ahe formation is modeled,compared with the Xu-White modeling with a single sandstone pore structure,it has a higher degree of agreement with measured curves.Finally,based on the modeled logging curves and rock physics interpretation plates,the tight gas reservoir of the Ahe formation was identified.After modeling,the elastic response characteristics of the gas reservoir are more pronounced,manifested as Poisson's ratio is less than 0.18,and the bulk modulus value is generally less than 3.0×10^(4)MPa.Seismic rock physics interpretation templates are established in this area to investigate the quantitative changes in elastic parameters caused by quantitative changes in fluid saturation under different"dry"rock matrices.This basically frames the elastic response window of gas reservoir,providing a reliable theoretical basis for reservoir and fluid prediction for following seismic reservoir inversion.

关 键 词：迪北斜坡带 致密砂岩气 孔隙结构预测 地震岩石物理 气层识别 

分 类 号：P618.13[天文地球—矿床学]