断裂-砂体复合输导体系输导效率的定量评价——以库车前陆盆地北带白垩系为例

Quantitative Evaluation of Transporting Efficiency of Composite Fault-sand Body Pathway System——By Taking the Cretaceous in the North Belt of Kuqa Foreland Basin for Example

作为库车前陆盆地北带白垩系油气成藏的主控因素之一,断裂-砂体复合输导体系的输导能力是决定油气能否成藏以及成藏规模的重要条件。在对研究区输导体系研究的基础上,选取适合前陆盆地输导体系的公式,分别计算了逆冲断裂和砂体输导体系的输导效率;同时对不同构造带输导体系的组合方式进行研究,拟定不同区带断裂、砂体输导体系对油气输导的贡献量。最后提出用权重法计算断裂-砂体复合输导体系输导效率的模型公式,并对研究区的复合输导效率进行评价。研究表明:受到沉积作用和山前构造挤压的双重控制,断裂-砂体复合输导体系的输导能力呈现出带状展布的特征,与已发现气藏具有较好的相关性,证明该模型公式对于天然气勘探具有一定的指导意义。其中,克拉地区断裂-砂体复合输导体系的相对输导系数大于90×10-2,是研究区输导条件最为有利的区域,其次为大北地区,再次为迪那地区。

The fault-sand body composite pathway system was one of the major controlling factors of hydrocarbon accumulation.Based on the research of pathway system,the transporting efficiency of thrust fault and sand body pathway system was calculated by choosing suitable formula for foreland basin.The contributions to the petroleum migration of the fault and sand body pathway system in different regions were determined after the combination way of pathway system in different structural belts is studied.The model formula of the transporting efficiency of fault-sand body composite pathway system is formed by using weight method,and then the transporting efficiency of the studied area is evaluated.The transporting ability of fault-sand body composite pathway system has good relation with the found hydrocarbon characterized by zonal distribution.It is demonstrated that the model formula is the guidance for gas reservoir exploration.The Kela Region is the most favorable area for the fault-sand body composite pathway system,with the relative transporting index bigger than 90×10-2,followed by Dabei and Dina Regions.