尼日尔三角洲深水勘探研究面临的挑战及其对策

面对深水勘探开发钻井和工程难度大、经济投资成本高的特点,针对深水区复杂油气藏,本文首先在深水研究区从深水重力构造形成机制和深水沉积储层研究入手,创新了深水研究区成藏规律认识。在深水重力构造研究方面,发现其由陆向海的演化模式,按演化和特征分成3种类型,建立深水沉积和重力控制下的构造模式;在深水沉积研究方面,以刻画深水沉积特征为基础,分析了海平面升降影响和重力流密度对深水沉积的控制作用,建立了两种深水沉积模式;然后通过研究重力构造、深水沉积与油气成藏三者的关系,确立了重力构造对深水油气成藏的主控作用,以及深水沉积储层与油气富集规律的关系,建立了深水油气成藏模式。在此基础上,提出了以断层为线索,落实构造,追踪油气,以沉积为单元,计算储量和资源量,进行深水高效勘探评价的新方法。并将上述思路应用到深水复杂油气藏勘探研究中,取得了较好的实际效果。

Challenges Faced with Deep Water Exploration and Its Strategies

Due to the fact that deep water exploration faces much difficulty in drilling and engineering as well as high cost in investment,this study started from analyzing the mechanism of deep-water gravity structures,and sedimentary reservoir in deep-water area,and then established reservoir-forming rules in deep water regions.In the aspect of deep water gravity structure,it is revealed that evolution mode from land to sea can be divided into three basic modes based on its evolution and features and the structure mode controlled by deep water deposition and gravity has also been established.In the aspect of deep water deposition,on the basis of depicting the deep water sedimentary features,this study analyzed controlling effect of up and down of sea level and density of gravity flow over deep water deposition and established two deep water sedimentary modes.Then by studying the relations between gravity structure,deep water deposition and hydrocarbon accumulation,gravity structure was finally defined as the leading factor controlling hydrocarbon accumulation,and deep water accumulation model was established.On the basis of that,a new highly efficient approach which takes sedimentation as unit was proposed to calculate reserves and resources in deep water areas using faults to trace hydrocarbon accumulation.And above-mentioned thought has also been applied to practical exploration in deep water complex hydrocarbon accumulation and better results have been achieved.