小草湖洼陷天然气成藏因素分析与勘探方向

Analysis of Natural Gas Accumulation Factors and Exploration Target in Xiaocaohu Area in Taibei Sag

吐哈盆地台北凹陷小草湖地区是吐哈油田天然气勘探的重要接替区域,该区天然气勘探已进入评价阶段,因此对天然气成藏控制因素分析和下一步勘探方向优选很有必要。研究认为,小草湖洼陷天然气成藏受构造、岩性,断层三重因素影响。天然气沿鼻隆脊部运移,在脊部高部位富集;鼻隆背景与岩性斜交和东西向断层的遮挡是天然气成藏的关键,沉积相带、物性和圈闭匹配情况对油气成藏也有重要影响。下洼找气思路和成藏模式结合将为小草湖天然气勘探迎来更大场面。

The area of Xiaocaohu in Taibei sag in Tuha basin is an important alternative region for natural gas prospecting in Tuba oil field. The exploration of natural gas in the area is in evaluation stage, so it is necessary to analyze the control factors of natural gas accumulation and optimize further targets of exploration. Through study, it Is thought that the natural gas accumulation in Xiaocaohu sub - sag is affected by three factors, structure, lithology and fault. The natural gas migrates along the back of nose -type uplift structure and accumulates at the high posi- tion. The oblique between nose - type uplift structure and lithology, and transmeridional fault＇s obstacle to oil - gas are vital to the natural gas accumulations. Matching of sedimentary facies belt, physical property and trap also has an important influence on natural gas accumulation. The idea of combining prospecting natural gas in low - lying with the mode of natural gas accumulation will bring a greater scene for natural gas prospecting.