基于全局自适应MCMC算法的裂缝型储层缝隙流体因子叠前地震反演  

Prestack seismic inversion of fluid factors in fractured reservoirs based on the global adaptive MCMC algorithm

作　　者：张婧 汪勇 赵慧言 衡德 黄君 张晓丹 王文文 贺燕冰 ZHANG Jing;WANG Yong;ZHAO Hui-Yan;HENG De;HUANG Jun;ZHANG Xiao-Dan;WANG Wen-Wen;HE Yan-Bing(Sichuan Changning Natural Gas Development Co.,Ltd.,Chengdu610000,China;Chengdu Jiekesi Petroleum Natural Gas Technology Development Co.,Ltd.,Chengdu610000,China)

机构地区：[1]四川长宁天然气开发有限责任公司,四川成都610000 [2]成都捷科思石油天然气技术发展有限公司,四川成都610000

出　　处：《物探与化探》2024年第1期105-112,共8页Geophysical and Geochemical Exploration

基　　金：重庆市自然科学基金面上项目“基于成岩系统剖析的致密砂岩储层差异致密化机理及渗流差异响应研究”(cstc2021jcyj-msxmX0897);自然资源部页岩气资源勘察重点实验室开放课题“中深层海相页岩微纳米尺度非均质性及其对渗流差异的影响机理研究”(KLSGE-202102)。

摘　　要：裂缝型储层通常具有各向异性特征,其缝隙中充填流体时会表现出不同的地震响应。为了准确识别裂缝性储层缝隙流体,为油气勘探开发后期的水力压裂过程起到重要的指示作用,本文首先引入准裂缝法向弱度以及准裂缝切向弱度的概念并构建了一个新的缝隙流体指示因子,结合线性滑动理论推导得到了裂缝诱导的HTI介质的弹性刚度矩阵表达式;然后基于散射理论以及Born近似方程推导获得了弱对比界面的线性化P波入射各向异性反射系数方程。此外,本文在MCMC算法的基础上引入了自适应策略,提出了改进的全局自适应MCMC反演算法。结果表明:(1)无噪时模型测试结果与测井数据达到了90%以上的吻合度。(2)实际数据反演结果与测井解释结果较为吻合,且在目标层段钻遇油气。西南某工区模型测试以及实际资料应用结果表明,本文提出的裂缝型储层缝隙流体因子叠前地震反演方法,反演结果与测井解释数据吻合程度较高,具有一定的可靠性与适用性,可实现流体准确识别以及指示水力压裂。Fractured reservoirs typically exhibit anisotropic characteristics,and their fractures show different seismic responses when filled with fluids.Accurate identification of fluids in fractured reservoirs plays a significant role in indicating the hydraulic fracturing process in the late hydrocarbon exploration and production stage.This study adopted the concepts of normal and tangential fracture qua-si-weaknesses and constructed a new indicative factor for fluids in fractures.Combining the linear slip theory,this study derived the e-lastic stiffness matrix expression of the fracture-induced HTI medium.Based on the scattering theory and the Born approximation equa-tion,this study derived the linearized P-wave incident anisotropic reflection coefficient equation for the weakly contrasted interface.Mo-reover,this study proposed an improved global adaptive MCMC algorithm by introducing the adaptation strategy into the MCMC algo-rithm.The results show that:(1)In the absence of noise,the model testing results were highly consistent with the log data,with a consis-tency degree of above 90%;(2)The inversion results of the actual data aligned closely with the log interpretation results,and hydrocar-bons were discovered through drilling in the target interval.As indicated by the results of model testing and actual data application in a study area in Southwest China,the prestack seismic inversion of fluid factors in fractured reservoirs,yielding highly consistent results with log interpretation data,demonstrates certain reliability and applicability and thus can achieve accurate fluid identification and hy-draulic fracturing indication.

关 键 词：裂缝型储层 流体识别 全局自适应 叠前地震反演 

分 类 号：P631.4[天文地球—地质矿产勘探]