摘要：

巴西桑托斯盆地盐下层系具有十分丰富的油气资源,白垩系BVE组湖相碳酸盐岩作为研究的重点与难点,在盐下区块的构造演化、沉积充填及油气成藏特征和富集规律方面已取得显著成果。由于BVE组湖相碳酸盐岩储集层储集空间复杂、非均质性强导致储集层精细表征难,制约了非常规油气的勘探开发进展。与常规测井相比,电成像测井更能直观地识别与评价非均质碳酸盐岩储集层,可在图像上快速识别出溶蚀孔和裂缝。基于岩心、薄片等地质资料,结合常规、电成像及核磁共振测井资料,归纳总结了该区块白垩系BVE组湖相碳酸盐岩储集层的储集空间类型,在此基础上将储集层划分为孔隙型、裂缝-溶孔型和裂缝型3类。利用岩心刻度常规测井、电成像测井资料建立了桑托斯盆地BVE组不同类型储集层测井识别图版,并完成单井纵向上储集层类型的连续识别和划分。桑托斯盆地盐下BVE组储集层的测井表征有助于完善盐下碳酸盐岩储集层测井评价体系,为盐下碳酸盐岩储集层中油气资源的高效开发提供理论指导和技术支撑。

关键词: 湖相碳酸盐岩储集层, 测井精细表征, BVE组, 桑托斯盆地

Abstract:

Hydrocarbon resources of the pre-salt reservoir in Santos Basin,Brazil shows good prospect. Many researchers have focused on the Cretaceous carbonate of the BVE Formation. A lot of research works have been done in structural evolution,sedimentary,and oil and gas accumulation,ect. However,due to the complex reservoir spaces and strong heterogeneity,well logging evaluation is challenging,which in turn restricts the advancement in oil and gas exploration and development in this area. Compared to conventional logs,electrical image log offers a more intuitive approach for identifying and evaluating heterogeneous carbonate reservoirs,particularly in the rapid detection of dissolution pores and fractures. In our study,experimental data,including cores and slices,and conventional log,as well as electrical image log and nuclear magnetic resonance log are integrated to analyze the reservoir space types. The reservoirs are classified into three types: porous reservoir,fracture-dissolution pore reservoir,and fracture reservoir. The identification standars of these types of reservoirs using well logs are established. This study hopes to improve the logging evaluation system of the pre-salt carbonate reservoirs,and provides guidance for highly effective reservoir development of carbonate reservoirs.

Key words: lacustrine carbonate reservoir, logging characteristics, BVE Formation, Santos Basin