川东北地区须家河组二段储层差异性分析

随着勘探程度的深入，为了扩大四川盆地天然气勘探领域、寻找新的勘探接替区，四川盆地的勘探区域由盆内逐渐向盆缘延伸。在这种背景下，川东北地区须家河组二段相继取得新的勘探成果，但在勘探开发过程中逐渐暴露了诸如区块之间气井产能差异大，储层的碎屑组分、结构及厚度、物性、孔隙结构差异明显等问题，制约了勘探开发的步伐。针对上述问题，根据岩芯观察描述、分析化验资料及测井解释成果，从沉积、成岩方面入手，对比剖析了川东北龙岗和营山地区须二段储层特征的差异性及其成因，认为远离物源区和高能水体的反复淘洗是造成储层差异性的首要因素，强烈的压实作用和多期石英加大对储层差异性起关键作用，自生绿泥石衬边胶结和长石选择性溶蚀最终决定了储层差异性。从而解释了气藏勘探开发中遇到的诸多问题，对有效指导该区的下一步勘探开发工作具有重要意义。

Analysis of Reservoir Differences of Member 2 of the XujiaheFormation in Northeast Sichuan Basin

With the deepening of the degree of exploration，and the expansion of the Sichuan Basin natural gas explorationfield，and to look for new exploration replacement area，Sichuan Basin exploration area extends from the basin to the basinmargin. In this context，successive new exploration results are obtained in the second section of the upper Triassic XujiaheFormation，but many problems gradually arose in the process of exploration and development，such as gas well productivitydifferences，clastic components，thickness and property differences of reservoir between blocks. In response to these problems，based on the core observation，core analysis data and log interpretation results，and starting from the analysis of deposition anddiagenesis，we make a comparative analysis with reservoir differences and its causes of Member 2 of the upper Triassic XujiaheFormation between Longgang and Yingshan Area. We think that far away distance from the source area and repeated washingby high-energy water are the primary factors causing reservoir differences；strong compaction and multistage quartz overgrowthare the key factors caused by the reservoir differences，and antigenic chlorite rim cementation and feldspar selective dissolutionare the ultimate factors causing the reservoir differences. The research results explain many of the problems encountered in theexploration and development of gas reservoirs，and provide effective guidance for the next step of exploration and developmentwork.