礁滩体与建设性成岩作用  

Reef-banks and reservoir-constructive diagenesis

作　　者：张宝民[1] 刘静江[2] 边立曾[3] 申银民[2] 贾进华[1] 张立平[1] 曹宏[1] 杨晓萍[1] 

机构地区：[1]中国石油勘探开发研究院石油地质实验研究中心,北京100083 [2]中国石油塔里木油田公司勘探开发研究院,新疆库尔勒841000 [3]南京大学地球科学系,江苏南京210093

出　　处：《地学前缘》2009年第1期270-289,共20页Earth Science Frontiers

基　　金：国家重点基础研究发展计划“973”项目(2007CB209502)

摘　　要：礁、礁丘、丘同属碳酸盐建隆,礁、滩是重要勘探目的层。但各自在沉积组分、组构、环境和时空分布,以及油气地质条件上迥然不同,因而无论从理论还是勘探实践上,都有必要将其各成体系划分开来。礁滩自身为好储集岩,当建设性成岩作用叠加后可形成好的储层。碳酸盐岩优质储层形成,主要受沉积微相与建设性成岩作用两大因素控制。前者是基础,并以高能的礁滩相带为最好;后者主要包括破裂、白云石化和溶蚀三大类,并以白云石化或溶蚀为最优,其中的溶蚀分布最广泛、影响最深刻而对优质储层形成起决定性作用。礁滩储层中的古岩溶类型最为丰富多彩,包括同生期、准同生期、表生期和埋藏期热流体岩溶的所有类型,白云岩化礁滩体也不例外。其中,同生-准同生期岩溶的形成机制与礁滩沉积时高频层序旋回向上变浅序列的短暂暴露淋溶有关,表生期岩溶则受控于礁滩沉积后三级层序旋回Ⅰ型界面的暴露淋溶。由此,导致礁滩储层中除了可以也是(碳酸盐岩中)唯一保存原生孔隙外,还发育了次生溶蚀孔洞缝和大型溶洞。礁丘、灰泥丘尤其是丘间洼地中发育高有机质丰度烃源岩;它们自身没有有效的原生孔隙,但岩溶作用可以形成次生孔隙。Reefs, reef-mounds and lime mud mounds are all carbonate buildups, and the reefs and banks are important targets for petroleum exploration. The reefs, banks and mounds should be divided from each other not only in theory, but also in exploration practice, because of so many differences in sedimentary compositions, fabrics, environments, distribution in time and space, and the characteristics of petroleum geology. If the original reef or bank itself was fine reservoir rocks, then it would become a better reservoir after the reservoir-constructive diagenesis. The formation of a high quality carbonate reservoir is controlled by two factors： the sedimentary microfacies and the reservoir-constructive diagenesis. The first is the basis for the formation of a high quality reservoir, and with the high energy reef-bank facies as the best; the latter includes the cataclasis, the dolomitization and the karstification. The dolomitization and karstification are the best for the formation of a high quality reservoir. The karstification has the widest distribution, profoundest effect, and plays a vital role in the high quality reservoir forming. The karst types are quite rich in the limestone reef or bank reservoir, including synsedimentary karst, pene-sedimentary karst, supergene karst and hydrothermal karst, and so does the dolomitization reef or bank reservoir. The formation mechanism of synsedimentary karst and pene-sedimentary karst is related to the short time exposing and leaching of the cyclical high-frequency shallow-upward sequence when the reefs or banks are forming. The supergene karst is controlled by the exposing and leaching of tertiary cyclic sequence type Ⅰ interface after the reefs or banks forming. Thus, there developed a great deal of secondary corrosion pores, corrosion fractures and huge caves besides some original pores remained in the reef and bank reservoir. Scarcely there are any original effective pores in reef-mounds and lime mud mounds, especially in senkes among mounds, but secondary pores coul

关 键 词：生物礁 礁丘 灰泥丘 滩 岩溶作用 破裂作用 白云石化作用 同生期岩溶 准同生期岩溶 表生期岩溶 

分 类 号：P618.130.21[天文地球—矿床学] P588.245[天文地球—地质学]