摘要
陡坡带是箕状凹陷中油气富集的一类重要构造带,具有紧邻油源、砂体极为发育、相变化快等特点,是油气勘探的重要目标。为了缓解埕北油田增储上产的压力,近年来对埕北低凸起南侧陡坡带进行了多轮滚动勘探,但是勘探效果不佳。在对埕北低凸起南侧陡坡带构造特征、地层发育及成藏条件分析的基础上,结合对已钻构造的精细解剖,总结了该区的成藏特征:一是圈闭的有效性控制了油气是否富集成藏;二是沉积相带控制了油气成藏的有利部位。分析认为,圈闭的有效性主要体现在控圈断层的封闭性,断层封闭性的好坏直接决定油气能否成藏。而不同的沉积相带,砂体横向非均质性较强,物性具有较大的差异。研究发现扇中是储集体中最好的储集相带,也是成藏的最有利部位。通过陡坡带成藏主控因素研究,对该区下一步的勘探部署起到至关重要的作用,同时对其它类似陡坡带提高勘探效率具有一定的指导意义。
Steep slope belt is characterized by close to the oil sources, with extremely well developed sand bodies, and rapid changes in sedimentary facies, being an important tectonic belt for hydrocarbon accumulation in dustpan-like depression. Therefore, it is an important target for hydrocarbon exploration. In recent years, in order to increase reserves and production of the Chenghei Oilfield, several rounds of rolling exploration have been conducted in the south steep slope of Chengbei low uplift, but the results of exploration are not good enough. Based on analyzing results on the tectonic characteristics, stratigraphy, hydrocarbon accumulation conditions in the south steep slope of Chengbei low uplift, combined with fine analysis of structures, the hydrocarbon accumulation characteristics are summarized as followings： Firstly, the trap effectiveness might control the oil and gas enrichment. Secondly, sedimentary facies might control the favorable position of hydrocarbon accumulation. It is believed through analysis that the effectiveness of traps is mainly controlled by the sealing capability of faults, and can determine whether hydrocarbon accumulation can occur. In different sedimentary facies belts, the sand bodies are very strong in the lateral heterogeneity, with great difference in physical properties. It is found through study that the mid-fan is the best reservoir facies belts and the most favorable part for hydrocarbon accumulation. The study about the main controlling factors on hydrocarbon accumulation has a crucial role for the next exploration in the south steep slope of Chengbei low uplift and other similar steep slope belts, and is significant for improving the exploration efficiency.
出处
《海洋石油》
CAS
2016年第1期36-41,共6页
Offshore Oil
基金
国家科技重大专项"大型油气田及煤层气开发"(2011ZX05023-006-002)
关键词
埕北低凸起
陡坡带
沉积相带
断层封闭性
成藏特征
Chengbei low uplift
steep slope belt
sedimentary facies
fault sealing
hydrocarbon accumulation characteristic
