含油气盆地碎屑岩储层碳酸盐胶结物研究进展

Research Progress on Carbonate Cements in Clastic Reservoirs in Petroliferous Basin

碳酸盐胶结物是寻找低孔低渗背景下或深部砂岩储层油气勘探“甜点”的关键因素之一,总结国内外学者的研究成果,对指导有利区带勘探和剩余油挖潜具有重要意义。首先,对中国含油气盆地碳酸盐胶结物类型及分布特征进行了系统总结,认为其分布具有盆地类型多样、时代跨度大、沉积相类型以丰富的三角洲相为主等特征;其类型以方解石和白云石两大类为主,根据铁离子质量分数可进一步细分为无铁、含铁和铁质碳酸盐胶结物三种类型。然后,对碳酸盐胶结物的形成期次、物质来源、离子运移及沉淀的影响因素进行了分析与总结,认为成岩过程中流体的来源、流动方式对碳酸盐胶结物的类型、成因机制及分布具有重要的控制作用。最后,总结了碳酸盐胶结物对储层质量影响的几种观点,并提出了目前碳酸盐胶结物对储层质量影响评价过程中的一些建议和有待进一步研究的难点问题。

Carbonate cementation is one of the key factors to search for oil and gas exploration Sweet spots in low porosity and low permeability or deep sandstone reservoirs.Summarizing the research results of scholars at home and abroad is of great significance for guiding the exploration of favorable zones and the potential of remaining oil.Firstly,the types and distribution characteristics of carbonate cements in oil-bearing basins in China were systematically summarized,and it is considered that their distribution is characterized by diverse basin types,large age spans,and sedimentary facies dominated by abundant delta facies.It is mainly composed of calcite and dolomite,and can be further subdivided into three types of iron-free,iron-bearing and iron-carbonate cements according to the content of iron ions.Then it is concluded that the source and flow of fluid in diagenesis play an important role in controlling the type,genetic mechanism and distribution of carbonate cement by analyzing and summarizing the formation stage,material source,ion migration and precipitation factors of carbonate cement.In the end,several viewpoints on the influence of carbonate cements on reservoir quality were summarized,and some suggestions on the evaluation of the influence of carbonate cements on reservoir quality and some difficult problems to be further studied were put forward.