摘要
四川盆地东部涪陵页岩气田五峰组-龙马溪组页岩气藏目前已投入商业开发,从一期开发区的开发效果来看,单井产能具有较大的差异,页岩气藏的含气性平面上也具有差异性,而造成其差异的主控因素尚不明确。根据地质评价,该区的页岩厚度、矿物成分和有机碳含量等原始品质平面展布稳定,不是影响该区页岩气藏含气性变化的主要因素,含气性的差异可能与构造形变有重要关系。从区域构造变形特征入手,对该区的结构特征、构造格架、构造样式等开展了研究,认为研究区经历了多期构造运动,发育多层次滑脱构造,纵向上可划分为3个构造形变层、7种局部构造样式,平面上的构造变形强度具有明显差异性。初步尝试对构造变形程度进行定量化表征,认为断距、地层增厚比例、曲率、断裂密度为表征该区构造变形强度的关键参数。通过对构造变形的定量化表征,将研究区分为4个构造形变区,不同区的页岩含气性具有明显的差异,明确了构造变形强度是造成该区含气性差异的关键因素。
The shale gas reservoirs of the Wufeng-Longmaxi Formations in the Fuling shale gas play,the eastern Sichuan Basin have been put into commercial production. In the first-phase development block, the single well productivities show a great difference and the gas storage varies laterally, but the causes are still poorly understood. The previous geological evaluation indicated that the lateral distributions of the primary reservoir qualities like shale thickness, mineral composi- tion, and organic carbon content are stable, thus could not be the key factors affecting gas storage. Instead, the variation of gas storage may be closely related to structural deformation. Starting with the characterization of regional structural deformation, this paper presents a systematical research on the structural features, tectonic framework and structural styles in the study area. The study area experienced multi-stage tectonic movements, resulting in multi-level decollement struc- tures, which can be vertically divided into 3 structural deformation layers and 7 structural styles, with an obvious differ- ence in structural deformation intensity. A preliminary quantitative characterization of the structural deformation intensity shows that the fault throw, formation thickening ratio, curvature and fault density are the key parameters for characterizing the structural deformation intensity of the study area. Based on the quantitative characterization, four structural deforma- tion areas are recognized in the study area, and they have significantly different gas storage, indicating that the structural deformation intensity is the key factor causing the variation of gas storage in the study area.
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
2016年第6期809-818,共10页
Oil & Gas Geology
基金
国家科技重大专项(2016ZX05060)
关键词
滑脱构造
构造样式
构造变形强度
含气性
页岩气藏
川东地区
detachment structure, structural style, structural deformation intensity, gas storage, shale gas play, easternSichuan Basin
