南海石炭系潜山储层特征及地震识别

南海某盆地A凹陷基底石炭系碳酸盐岩遭受了二叠纪-白垩纪期间漫长地质时期的风化和侵蚀，发育了大量的优质碳酸盐岩岩溶型储集层。但碳酸盐岩潜山岩溶型储层发育的复杂性，一直制约着对其进一步的勘探。为此，通过对岩溶型储集层的划分对比，认为该区岩溶型储集层可以划分为表层岩溶带、渗流岩溶带和潜流岩溶带；其储集层主要以溶蚀孔洞、洞穴以及构造裂缝组成，其中溶蚀孔洞、洞穴是主要的储集空间，构造裂缝主要起着连通基质孔隙、溶蚀孔洞、洞穴和改善储集层渗滤条件的作用。利用钻井资料对岩溶型储集层进行标定后，认为表层岩溶储集层为弱振幅、弱连续（低相干）和低阻抗的特征，内幕储集层则为短轴状强振幅、高能量和低阻抗的特征，能够利用地震属性对岩溶型储集层进行识别。

RESERVOIR CHARACTERISTICS AND SEISMIC IDENTIFICATION IN CARBONIFEROUS BURIED HILL IN SOUTH CHINA SEA

Carboniferous carbonate in the basement of A depression in South China Sea has suffered the weathering and erosion actions for long geological ages during Permian Cretaceous, hence, a lot of favorable carbonate karst reservoirs are developed there. However, further exploration has always been constrained by the complexity of the karst reservoir development in carbonate buried hill. Based on the classification and comparison of the karst reservoirs, the paper concluded that the karst reservoirs in this region could be classified into Epikarst zone, vadose karst zone and underflow karst zone. The reservoirs are primarily composed of solution vugs, cavities and structural fractures, among which solution vugs and cavities are the main storage spaces while structural fractures mainly play roles connecting the matrix pores, solution vugs as well as cavities, and improving the infiltration of reservoirs. By using drilling information to calibrate the karst reservoir, it is concluded that Epikarst zone is characterized by weak amplitude, weak connectivity (low coherence) and low impedance while the inner reservoir is characterized by minor phase axis, strong amplitude, high energy and low impedance, therefore, the karst reservoirs can be identified with seismic attributes.