富县地区长7页岩油气富集特征与主控因素

Oil and gas enrichment characteristics and main controlling factors of Chang7 shale in Fuxian Area

为了摸清富县地区长7页岩油气富集特征与主控因素,以富县地区长7页岩油气勘探实践为基础,结合前人的研究成果,通过分析成藏地质背景、页岩层系内部油气运聚特征以及页岩油气富集特征及模式,对油气富集主控因素进行研究,研究结果表明:1)长7砂岩油藏类型主要为透镜体油藏和上倾尖灭型油藏,已发现油藏主要分布在长7顶部,在研究区东部长7底部发育少量油藏;纵向上烃源岩底部、顶部的砂体、夹在两套烃源岩中间的砂体往往是有利的勘探目标。2)平面上,在研究区中西部长7油藏主要沿三角洲前缘砂体的环古湖岸线、主分流河道分布,在研究区东部油藏主要分布于位于流线汇聚区及流线与砂体大角度相交区域。3)总体来看,页岩段中部、中下部油气含量要高于页岩段上部的油气含量。影响页岩油气含量的因素复杂,主要有TOC、有机质成熟度、黏土矿物含量、孔隙及孔隙结构等,该成果为富县地区长7页岩油气下一步的高效开发,具有一定的指导意义。

In order to find out the oil and gas enrichment characteristics and main controlling factors of Chang7 shale in Fuxian Area,based on the exploration practice of Chang7 shale in Fuxian area,combined with previous research results,the research results of main controlling factors of oil and gas enrichment are clarified by analyzing the geological background of reservoir formation,the characteristics of oil and gas migration and accumulation in shale series,and the characteristics and patterns of shale oil and gas enrichment,The results show that:1)Chang7 sandstone reservoirs are mainly lenticular reservoirs and updip pinch out reservoirs.It has been found that the reservoirs are mainly distributed at the top of Chang7,and a small number of reservoirs are developed at the bottom of Chang7 in the east of the study area;In vertical direction,sand bodies at the bottom and top of the source rock,and sand bodies sandwiched between two sets of source rocks are often favorable exploration targets.2)On the plane,the Chang7 reservoir in the west and east of the study area is mainly distributed along the ancient lake shoreline and the main distributary channel of the delta front sand body,while the reservoir in the east of the study area is mainly distributed in the streamline convergence area and the area where the streamline intersects the sand body at a large angle.3)On the whole,the oil and gas content in the middle and lower part of the shale section is higher than that in the upper part of the shale section.The factors affecting shale oil and gas content are complex,mainly including TOC,organic matter maturity,clay mineral content,pore and pore structure,etc.This achievement is of guiding significance for the next step of efficient development of Chang7 shale oil and gas in Fuxian Area.