中国海相碳酸盐岩勘探领域拓展历程及沉积学的基本驱动作用

回顾中国碳酸盐岩油气勘探领域的拓展历程,共经历了三个阶段:第一阶段,上世纪中后期以靖边气田等为代表的找构造高部位的岩溶型油气藏阶段;第二阶段,2000年以来以普光气田等为代表的台地边缘礁滩油气藏拓展阶段;第三阶段,2010年以来克拉通内幕白云岩油气藏新拓展阶段。沉积学的三种基本的水动力储层宏观成因模式是三大碳酸盐岩勘探领域拓展的基本驱动因素:早期勘探阶段的构造高部位岩溶储层宏观分布受控于隆起暴露期的大气水岩溶作用,台缘礁滩储层的宏观分布受控于镶边台地边缘持续的波浪作用,内幕白云岩储层的宏观分布则受控于潮汐作用。大气水岩溶模式的古水文地质系统除了作用于不整合面附近的隆起区,构造低部位和被断裂沟通的远离不整合面地区也能够发育岩溶储层,值得注意的是短暂暴露的准同生岩溶是未来重要勘探方向。浪控台缘礁滩模式具有“盆包台”、“台包盆”、“盆切台”等多种台缘结构模式,它们的储层宏观分布都处于波浪作用的高能礁滩带上,都基本符合威尔逊碳酸盐岩台地模式,只是不同地区的台地边缘具有不同的复杂形状而已,识别深部隐伏裂陷及其周缘礁滩相带是该领域勘探的难点。潮控陆表海台地潮坪模式指导了碳酸盐岩勘探向克拉通内幕白云岩的拓展,该类白云岩储层呈大面积薄互层席状产出,其宏观分布具有进积潮坪楔和潮坪岛拼嵌两种样式,是一个重要的勘探新领域。

Marine Carbonate Exploration History and the Basic Driving Action from Sedimentology in China

Reviewed the development of the carbonate oil & gas exploration in China, there have three stages: the first stage is in the later 20thcentury, represented by the Jingbian gas field in Ordos Basin discov ered from karstic carbonate reservoirs at its central palaeouplift,the second stage is in the 2000s,represented by the Puguang gas field of Sichuan Basin discovered from reef-bank reservoir of the platform edge,and the third stage is 2010 up to now repre-sented by intracratonic dolomite reservoirs in Ordos Basin. Three basic types of reservoir hydrodynamic model is the basic driving factors of three carbonate exploration stages:the macro distribution of karst reservoir in the early stage of carbonate exploration is controlled by atmospheric fresh water karstification,the macro distribution of reef-bank reser-voir in the second stage is controlled by wave action of the platform edge,and the macro distribution of intracratonic dolomite reservoir is controlled by tidal action of epeiric sea. The ancient hydrogeological system of the atmospheric fresh water model not only plays the role for the karst reservoir in the uplift zone near the unconformity surface,but al-so in the low structural parts and the carbonate buried away from the unconformity surface linked by fracture. Further-more,it is worth noting that penecontemporaneous karst caused by the short exposure period is an important explora-tion direction in the future. Wave controlling platform margin reef-bank model have many structural types, such as"platforms surrounded by a basin","basins surrounded by a platform"and"platforms cut by basins".Their reservoir macro-distribution is all controlled by wave action,and basically fit the Wilson carbonate platform model,just has dif-ferent complex shapes. Identification on the deep concealed rift and its peripheral reef facies belt is the key factor for this type of carbonate exploration. Tidal controlling epeiric sea dolomite model guides the intracratonic carbonate ex-ploration. This type of dolomite reservoir occurs broadly in thin interbed sheet,its macro-distribution controlled by the tidal flat progradation wedge and mosaic of tidal flat islands,which is an important new exploration field.