基于精确Zoeppritz方程的时移地震流体动态监测  

Time-lapse seismic inversion for fluid dynamic monitoring based on the exact Zoeppritz equations

作　　者：周林[1] 廖建平[1] 袁成 刘彦鑫 赵超 陈小宏[5] ZHOU Lin;LIAO JianPing;YUAN Cheng;LIU YanXin;ZHAO Chao;CHEN XiaoHong(School of Earth Sciences and Spatial Information Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;Research Institute of Petroleum Exploration and Development-Northwest,PetroChina,Lanzhou 730020,China;Exploration and Development Research Institute,PetroChina,Qinghai Oilfield Company,Dunhuang 736202,China;Drilling Technology Research Institute,PetroChina,Qinghai Oilfield Company,Dunhuang 736202,China;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China)

机构地区：[1]湖南科技大学地球科学与空间信息工程学院,湘潭411201 [2]中国石油勘探开发研究院西北分院,兰州730020 [3]中国石油天然气股份有限公司青海油田分公司勘探开发研究院,敦煌736202 [4]中国石油天然气股份有限公司青海油田分公司钻采工艺研究院,敦煌736202 [5]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249

出　　处：《地球物理学进展》2022年第5期2118-2128,共11页Progress in Geophysics

基　　金：国家自然科学基金项目(41904116,41874156,42074167);湖南省自然科学基金项目(2020JJ5168);中国石化地球物理重点实验室开放基金(33550006-22FW0399-0027,3550006-20-ZC0699-0012-ZR01)联合资助。

摘　　要：储层流体动态定量评价能够为剩余油开发提供重要信息.流体因子作为一种重要流体表征参数,能有效识别流体位置和类型,理论上可根据油藏开发引起的流体因子变化量实现流体动态监测.通常,流体因子变化量可以利用常规弹性参数间接计算或基于近似公式直接反演得到.但间接计算引入的累积误差及近似公式较低的精度会严重影响其预测精度和分辨率.因此,为了在发挥流体因子优势的同时克服上述问题,本文研究了一种基于精确Zoeppritz方程的时移地震流体因子变化量反演方法.首先,推导包含流体因子的新形式精确Zoeppritz方程;然后,借助泰勒级数展开推导基于上述新方程的时移地震差异数据正演方程;最后,利用该差异数据正演方程构建贝叶斯框架下的目标函数,并通过引入服从微分拉普拉斯分布的块约束项提升反演结果对储层边界的刻画能力.合成数据和实际数据测试表明,新方法能够从差异数据中合理地估计流体因子变化量并实现储层流体动态监测,充分验证了方法的可行性和有效性.Ascertaining the fluid dynamic of reservoirs can provide very important information for the design of subsequent well drilling and recovery of remaining oil.Fluid factor,as an important fluid characterization parameter,can effectively identify the position and type of fluid.In theory,reservoir fluid dynamic monitoring can be achieved according to fluid factor changes which caused by reservoir production.In general,the changes in fluid are calculated indirectly by using the inversion results of elastic properties or inverted directly based on approximations.But the accumulative error caused by indirect calculation and low calculation accuracy of approximations will seriously affect the prediction accuracy and resolution of the changes in reservoir fluid.Therefore,we study time-lapse seismic inversion for the changes in fluid factor based on the exact Zoeppritz equations directly to taking advantage of the fluid factor while overcome the above problems.Firstly,we derive a new form of the exact Zoeppritz equations containing fluid sensitivity factor.Then,a novel forward equation of time-lapse seismic difference data is derived using Taylor series expansion based on the new Zoeppritz equations.Finally,we construct an objective function by using this novel forward equation in a Bayesian framework with the addition of a differentiable Laplace distribution blockiness constraint term to the prior model to enhance fluid boundaries.Both synthetic and field data examples show that the proposed method can reasonably estimate the changes in fluid factor from the difference data and achieve fluid dynamic monitoring,which verifies the feasibility and effectiveness of the new method.

关 键 词：时移地震反演 流体因子 精确Zoeppritz方程 流体动态监测 

分 类 号：P631[天文地球—地质矿产勘探]