琼东南盆地深水区浅层运聚系统及其对天然气水合物成藏的控制

以琼东南盆地连片三维地震资料为基础，精细识别盆地浅层多种类型运移通道，系统总结了盆地深水区浅层运聚系统发育特征，并探讨其对天然气水合物成藏的控制，预测了天然气水合物有利目标区。研究结果表明：琼东南盆地浅层运移通道主要包括断层、气烟囱、裂隙、大型侵蚀不整合面和盆缘大型储集体，多种类型运移通道空间上相互组合，共同构建成盆地浅层流体运聚系统；不同区域浅层流体运移通道发育程度不一样，陵南-松南低凸起浅层流体运移通道最为发育，中央坳陷发育程度次之，浅水区相对不发育；琼东南盆地深水区浅层流体运聚系统控制着天然气水合物的分布，对中深层天然气勘探也具有重要的指示作用。总之，琼东南盆地浅层流体运移通道较发育，其中最为发育的陵南-松南低凸起是盆地天然气水合物规模成藏最为有利的场所，松南-宝岛凹陷陆坡区也具备优越的水合物成藏条件。

SHALLOW MIGRATION AND ACCUMULATION SYSTEMS IN THE DEEP WATER AREAS OF THE QIONGDONGNAN BASIN AND THEIR CONTROL ON NATURAL GAS HYDRATE ACCUMULATION

Continuous 3D seismic survey has been carried out in the Qiongdongnan Basin, and various types of migration channels are discovered. Based on the characteristics of shallow migration and accumulation system in the deep-water areas of the basin, this paper is devoted to the mechanisms which controls the deposition and accumulation of natural gas hydrate (NGH). Favorable target areas for NGH exploration are predicted upon the basis. It is revealed that the shallow fluid migration channels of the Qiongdongnan Basin mainly consist of faults, gas chimneys, fractures, erosion unconformities and large reservoirs along the border of the basin. Various types of migration channels are always combined in space to form shallow migration and accumulation systems. The development status of the shallow fluid migration channels system varies from place to place. The most developed areas include the Lingnan - Songnan Low Uplift and the Central Depression of the basin, while in the shallow water areas, the systems are relatively undeveloped. The shallow fluid migration and accumulation systems in the deep-water areas of the Qiongdongnan Basin not only control the distribution of NGH, but also influence the gas exploration of the middle and deep layer deposits. To sum up, the shallow fluid migration channels are relatively developed in the Qiongdongnan Basin, and the Lingnan-Songnan Low Uplift is the most favorable zone within the basin, and the continental slope areas of the Songnan-Baodao Sag also have excellent conditions for NGH accumulation.