摘要
[目的]在油气水储层中,生物扰动通过改变原生沉积组构降低或提高地层的孔隙度和渗透率,进而影响储层物性和流体流动特征。[方法]为了调研生物扰动储层的研究现状及进展,结合前人和笔者团队近年的研究成果,系统梳理和归纳总结了生物扰动油气水储层的储集空间类型、孔隙结构特征、储层介质类型、流体传输特征、储层类型及其属性特征。[结果](1)生物扰动储层的储集空间类型包括:原生粒间孔、粒内溶孔、粒间溶孔和晶间孔等;(2)生物扰动储层可划分为双孔隙度生物成因储层介质和双渗透率生物成因储层介质,两类储层介质在生物潜穴类型、运移动力、流体传输特征、沉积环境等方面存在不同程度的差异;(3)生物扰动储层包括界面控制的生物扰动储层、非界面控制的生物扰动储层、边界不清晰的生物扰动储层、隐蔽性生物扰动储层、成岩成因的生物扰动储层五种类型,潜穴充填物和基质渗透率比、生物扰动强度和连通性、生物潜穴表面积、潜穴的构型特征是影响生物扰动储层岩石物性的主控因素。[结论]尽管生物扰动储层的共同特征已被充分记录,但国内外对于生物扰动储层的研究还处于初级阶段,但可预见的是加强生物扰动储层的研究对丰富储层地质学理论,实现油气增储、上产和提高采收率具有重要意义。
[Objective]In bioturbated hydrocarbon and water reservoirs,bioturbation changes the petrophysical properties of the host rocks by changing the primary sedimentary fabric,reducing or increasing the porosity and per-meability of the primary formation,which in turn affects the reservoir petrophysical properties and fluid flow charac-teristics.To investigate the research status and progress of bioturbated hydrocarbon and water reservoirs,[Methods]combined with recent research results,the reservoir space types,pore structure characteristics,reservoir media na-ture,fluid transport characteristics,reservoir types,and their property characteristics of bioturbation hydrocarbon and water reservoirs have been sorted and summarized.[Results]The results show that:(1)The reservoir space types of bioturbated reservoirs include:primary intergranular,intra-grain dissolved,inter-grain dissolved,and inter-granular pores.In bioturbated clastic rock reservoirs,typical reservoir spaces are primary intergranular,secondary dissolution,and biological mold pores.The early primary pores were filled with calcareous cements to reduce porosity and permeability,but in the subsequent diagenesis,if these calcareous cements were dissolved,these intergranular pores could be preserved.In bioturbated carbonate reservoirs,typical respace spaces contain primary intergranular,intercrystalline,and dissolution pores.Syngeneic or early diagenetic dissolution is the key factor in the development of bioturbated carbonate reservoir space.(2)Based on the relationship between the permeability of burrows and the host sediments,the bioturbated reservoir can be divided into dual-porosity and dual-permeability biogenic reservoir media,and the two types of reservoir media have significant differences in burrow types,migration dynamics,fluid transport characteristics,and depositional environment.At present,there are two main research approaches to the study of fluid transport characteristics in bioturbation reservoirs:physical and numerical simulation.The physical simulation shows a broader range for pore volumes exchanged to better illustrate the leading exhibited by burrowed carbonate rocks.The numerical simulation reveals a well-connected burrow network can occur in strata of as little as 12%burrow intensity,and burrow connectivity increases nonlinearly with increasing burrow intensity.Numerical flow simulations of Thalassinoides Burrow Networks(TBN)models indicate that cumulative gas production(GPC)is controlled primarily by TBN connectivity and matrix permeability.With an impermeable matrix,production comes through TBN,starting only at a burrow intensity of 30%,and GPC increases linearly with burrow intensity.With a permeable matrix,and low permeability contrast between matrix and TBN(one order of magnitude)production starts at relatively low TBN intensity(4%),and GPC increases nonlinearly with burrow intensity.The interaction between matrix and TBN connects more isolated TBN bodies and increases GPC,likely helping the gas diffusion from matrix through TBN.The fluid flow simulation also illustrates the likelihood of the presence of permeability that drives early water breakthrough(super-K)at burrow intensity>50%.The results advance the quantitative understanding of the impact of burrow connectivity on fluid flow properties of TBN-bearing strata and provide a workflow that can be used to model other burrow morphologies and understand their impact on flow properties of bioturbated reservoirs.(3)Based on the burrow characteristics of bioturbated reservoirs,fluid transport characteristics in reservoir media,and reservoir petrophysical characteristics,bioturbated reservoirs can be divided into five types:Surface-constrained,Non-surface-constrained,Weakly defined,Cryptic,and Diagenetic.The main controlling factors affect-ing the petroproperties of bioturbated reservoirs are analyzed in detail,including the permeability ratio of burrow-fills and hosting matrix,bioturbation intensity and connectivity,burrow-surface area,and burrow architecture.[Conclu-sions]Although the common characteristics of bioturbated reservoirs have been fully documented,the domestic and international relevant research on bioturbated hydrocarbon and water reservoirs is still in its primary stage;however,strengthening these studies is of great significance and imparts important implications for enriching the theory of reser-voir geology,increasing oil and gas storage,and enhancing production and recovery.
作者
牛永斌
荆楚涵
邵威猛
程怡高
李志远
NIU YongBin;JING ChuHan;SHAO WeiMeng;CHENG YiGao;LI ZhiYuan(School of Resource&Environment,Henan Polytechnic University,Jiaozuo,Henan 454003,China;Henan International Joint Laboratory of Biogenic Traces and Sedimentary Minerals,Jiaozuo,Henan 454003,China)
出处
《沉积学报》
CAS
CSCD
北大核心
2023年第6期1934-1953,共20页
Acta Sedimentologica Sinica
基金
国家自然科学基金项目(41472104,42272178)
河南省高校科技创新项目(21IRTSTHN007)
河南理工大学科技创新项目(T2020-4)。
关键词
生物扰动
油气储层
储集空间
孔隙度
渗透率
bioturbation
hydrocarbon reservoir
reservoir space
porosity
permeability
