琼东南盆地深水区流体势场恢复与有利区带研究

Fluid Potential Field Restoration and Favorable Zone Optimization in the Deep-Water Area of Southeast Hainan Basin

勘探实践表明,油气运移误判严重制约了琼东南盆地深水区的油气勘探,导致下一步勘探方向不明,而流体势是运移研究中的关键一环。为解决这个问题,基于区内构造和沉积等资料,在明确构造对流体势场控制机理的基础上,利用盆地模拟软件,恢复了深水区流体势场演化史。研究表明,新生代的构造运动影响流体势场的弹性能、界面能、重力能的形成及演化,控制了区内的油气运移,形成了深水区流体势横向上由凹内到凹外,纵向上由深层到浅层逐渐降低的特征。同时,构造运动也是深水区流体势能量场不断调整的诱因,伴随着地下油气大量的集中运移和油气田的形成。基于此,优选出位于凹内深部高势烃源浅层低势区的陵水-宝岛凹中反转构造带,以及被高势烃源包围低势区的松南低凸起披覆背斜构造带,作为深水区继中央峡谷外的最有利区带。研究成果对指导深水区下一步勘探方向的选择有重要意义。

Exploration practices show that the hydrocarbon migration misjudgment severely restricts the hydrocarbon exploration and the future exploration direction in the deep-water area of Southeast Hainan Basin. Fluid potential is one of the key aspects in the hydrocarbon migration. The structure, sedimentation and other data were used to solve this problem. Based on the structure control mechanism of the fluid potential field, the basin simulation software was used to restore the evolution history of the fluid potential field in the deep-water area. Research indicates that the Cenozoic tectonic movement affects the generation and evolution of elastic energy, interfacial energy and gravity en ergy for the fluid potential field. The hydrocarbon migration in this area is also dependent on the Cenozoic tectonic movement. The fluid potential in the deep-water area is characterized by a decrease from the inner concave to outer concave in the lateral direction and a decrease from deep to shallow in the longitudinal direction. Tectonic movement is also considered as the cause of continuous fluid potential field adjustment in the deep-water area, which was ac companied by the large-scale hydrocarbon migration and accumulation. The most favorable zone outside the central canyon in the deep-water area were optimized based on the above, including the Lingshui-Baodao concave center inversion structural zone in the shallow low-potential area of inner concave deep part with high-potential hydrocar bon source and the Songnan low-potential low-bulging draping anticline structure zone surrounded by the high-po tential hydrocarbon source. This research could provide certain guidance for the future hydrocarbon exploration in the deep-water area.