以地震为主的无井区生物礁潜力评价——以川东南赤水石牛栏组为例

Potential Evaluation of Reef in No Well Area by Seismic—Take the Shiniulan Formation of Chishui in Southeast Sichuan as an Example

摘要: 川南志留系油气资源丰富，勘探潜力巨大。赤水地区石牛栏组沉积期处于“四周陆、中间海”的古地理背景，由南向北为碳酸盐台地沉积转换成陆棚沉积。通过对野外剖面、钻井资料分析认为石牛栏组中上部发育珊瑚、海百合等台缘礁滩相碳酸盐岩。结合赤水二维地震剖面精细解释，认为赤水地区在凯旋–盘龙–葫市区域发育厚大台缘礁滩，石牛栏组地层厚度明显增厚，地震剖面上“丘状反射”特征明显。通过已钻井分析结合模型正演，认为石牛栏组中上部优质礁滩储层发育，地震剖面上呈“强波谷”反射特征。结合地震属性及地震异常识别，提出凯旋–盘龙–葫市为有利台缘滩相储层发育带为下一步有利勘探目标区。

Abstract: The south Sichuan is rich in oil and gas resources and has great exploration potential. The Shini-ulan’s Paleogeographic background was in “surrounding land and middle sea”, from south to north, carbonate platform deposits are transformed into shelf deposits. Based on the analysis of field profile and drilling data, it is concluded that there are some platform marginal reef-shoal carbonate rocks such as coral and crinoid in the middle and upper part of Shiniulan. Combined with the detailed interpretation of the 2D seismic profile in Chishui, it is considered that the thick margin reef beach is developed in Kaixuan-Panlong-Hushiarea, the Shiniulan’s thickness is thickening obviously, and the “mound reflection” feature is obvious in the seismic profile. Based on well analysis and model simulation, it is considered that the high quality reef reservoir is developed in the middle and upper part of Shiniulan formation, and the seismic profile shows “strong trough” reflection feature. Combined with seismic attributes and seismic anomaly identification, it is proposed that Kaixuan-Panlong-Hushi is a favorable platform margin beach reservoir development zone and a favorable exploration target area in the future.