方正断陷白垩系砂砾岩成岩作用及对储层物性的控制  

Cretaceous Glutenite Diagenesis and Its Effects on Reservoir Physical Properties in Fangzheng Fault-Depression

作　　者：王有智[1] 郑洪涛 田彦林 Wang Youzhi;Zheng Hongtao;Tian Yanlin(PetroChina Daqing Oilfield Company Limited,Daqing,Heilongjiang 163712,China;Liaohe Petroleum Career Technical College,Panjin,Liaoning 124000,China;PetroChina Huabei Oilfield Company,Renqiu,Hebei 062552,China)

机构地区：[1]中国石油大庆油田有限责任公司,黑龙江大庆163712 [2]辽河石油职业技术学院,辽宁盘锦124000 [3]中国石油华北油田分公司,河北任丘062552

出　　处：《特种油气藏》2019年第4期38-44,共7页Special Oil & Gas Reservoirs

基　　金：国家自然科学青年基金“塔北奥陶系露头含油古钙华的形成机制及储集能力”(41702154)

摘　　要：砂砾岩体作为近年来重要的油气勘探领域,其非均质性特征明显,因而成岩作用对其储集性能影响显著。针对方正断陷白垩系砂砾岩储层致密控制因素不明确的问题,利用岩心、铸体薄片、扫描电镜、能谱分析及XRD等分析方法,对研究区砂砾岩储层成岩作用类型及其对储层物性的影响进行了研究。结果表明:研究区砂砾岩主要存在4种成岩作用类型,压实作用、溶蚀作用和胶结作用对储层物性影响较大,交代作用对整体物性而言影响有限。砂砾岩储层经历了较为强烈的机械压实作用,严重破坏了储层的原生孔隙,平均减孔15.97%,是导致白垩系砂砾岩储层致密化的最主要原因;外来烃类流体的注入,大量的有机酸通过残留孔隙和裂缝进入储层,促进了钾长石等矿物的溶解,形成次生孔隙带,改善了砂砾岩储集性能,增孔6.79%;胶结作用充填原生和次生孔隙,减孔6.53%,是储层致密的另一关键因素。通过砂砾岩储层物性分析,认为方正断陷白垩系优质储层主要发育在靠近油源断裂的扇三角洲前缘水下分流河道细砾岩体中,前缘扇体原始孔隙度较高,是形成储层的物质基础,而且靠近油源断裂,利于烃类注入成储。该研究对方正断陷致密砂砾岩油藏的有效储层评价、有利勘探区带优选及目标优选等均具有一定的指导意义。As an essential hydrocarbon exploration field in recent years,glutenite is characterized by distinct heterogeneity,which shows a significant effect on reservoir performance.In order to identify the major controlling factors for the Cretaceous glutenite tight reservoir in Fangzheng Fault-Depression,the core test,casting thin-section analysis,scanning electron microscopy,energy spectrum analysis,XRD analysis and other means were used to determine the glutenite reservoir diagenesis types and their effects on reservoir properties.Result indicates 4 dominant diagenesis types for the glutenite in the study area.The reservoir physical properties are greatly dependent on the compaction,dissolution and cementation and slight dependent on the metasomatosis.The glutenite reservoir experienced a relatively strong mechanical compaction,which severely destroys the original reservoir pores and leads to an average reduction of 15.97%.This mechanical compaction is considered as the major reason leading to the densification of the Cretaceous glutenite reservoir.The foreign hydrocarbon fluid injection and a large amount of organic acid flowing into reservoir through residual pores and cracks promotes the mineral dissolution,which results in the development of secondary pore zones and glutenite reservoir improvement with an average increment of 6.79%.The cementation reduces the porosity by 6.53%through filling the primary and secondary pores,which is another key factor for reservoir densification.According to the physical property analysis of glutenite reservoir,it is believed that the Cretaceous high-quality reservoirs in Fangzheng Fault-Depression mainly distribute in the underwater distributary channel fine conglomerate mass of the fan delta front near oil-source fault.The leading edge of the fan shows a high original porosity,which is considered as the material basis for the reservoir formation.In addition,the leading edge of the fan is close to the oil-source fault,which is favorable for hydrocarbon charging and accumulation.Th

关 键 词：砂砾岩 储集空间 成岩作用 孔隙演化 方正断陷 

分 类 号：TE122.1[石油与天然气工程—油气勘探]