库车坳陷北带断裂输导效率及其物理模拟实验研究

Gas transport efficiency through fault and its physical simulation in the north belt of Kuqa depression

在分析断裂输导能力影响因素的基础上,建立了断裂输导天然气效率的评价方法,并用该方法从平面上对库车坳陷北带断裂输导天然气效率进行了评价,同时利用物理模拟实验再现了天然气的运聚成藏(或散失)过程,进而总结了该区断裂组合输导模式。研究结果表明,该区高、中、低效断裂输导体系的分布区域与天然气的分布具有较好的相关性,高效的断裂输导是库车坳陷北带天然气运聚成藏的重要条件。库车坳陷北带在垂向上主要有4种构造断裂输导模式,由盐下断裂与不直接连接圈闭的穿盐断裂构成的断裂输导模式和仅由盐下断裂构成的断裂输导模式是库车坳陷北带有效的断裂输导模式;而由盐下断裂与圈闭破坏断裂、穿盐断裂构成的断裂输导模式和仅由单一穿盐断裂构成的断裂输导模式是库车坳陷北带无效的断裂输导模式。

Based on the analysis of factors influencing gas transporting ability through fault, a novel evaluation method of gas transport efficiency through fault was given. The gas transport efficiency through fault was evaluated in plane by the method in the north belt of Kuqa depression. The results show that the distribution of high, middle and low efficiency fault transporting system is preferable correlation with natural gas distribution, and fault transportation of high efficiency is an important condition of natural gas migration and accumulation in the area. The natural gas migration and accumulation and scattering loss process was physically simulated. And the fault transport model was summarized in the area. There are four transport models： the fault transport model composing salt-underlying fault with cutting salt fault and the fault transportation model formed by only salt-underlying fault which are effective models and the fault transportation model composing salt-underlying fault with damaging trap fault and cutting salt fault and the fault transportation model formed by only cutting salt fault which are ineffective models.