论文部分内容阅读
为了解中国小型断陷湖盆致密油资源潜力,以中国西北地区雅布赖盆地中侏罗统新河组下段为研究对象,依据大量地球化学、物性、薄片、电镜和能谱等资料,对盆地致密油地质特征进行了系统研究。研究结果表明:1新河组下段源岩沉积中心与沉降中心不重合,高丰度源岩(TOC>1%)主要分布在中部、东部次凹;成熟源岩分布在中部、西部次凹;2砂岩储层矿物成分主要为石英、长石、碳酸盐岩和黏土等,石英和长石含量较高,均值达60%;储层物性较差,孔隙度、渗透率一般小于10%和1×10-3μm2,含油饱和度在10%~60%之间,最高可达70%;3含油致密储层,纵向上主要分布在中下部,平面上主要分布在小湖次凹;主要发育粒内孔、粒间孔、微裂缝和有机质孔等4种孔隙空间类型,前3种孔缝在各种矿物中较为常见,后者则较少见;4新河组下段油层压力系数较高、油质较轻,致密砂岩中油气以粒间孔中含油、溶蚀孔隙中含油、晶间孔中含油和微裂缝中含油4种方式赋存。雅布赖盆地新河组下段存在小湖次凹深洼带和盐场次凹斜坡带2个致密油勘探有利区,目前小湖次凹深洼带已获得工业油流突破,资源潜力较大,为下步勘探有利区带。
In order to understand the potential of tight oil resources in small-scale fault-depression lacustrine basins in China, the lower part of the Middle Jurassic Xinhe Formation in the Yabulaisi Basin, Northwest China, is selected as the research object. Based on a large number of geochemical, physical, flaky, electron and energy spectrum data, Basin tight oil geological characteristics of a systematic study. The results show that: (1) The sedimentary center and center of source rocks in the lower part of Xinhe Formation do not coincide with each other. The source rocks with high abundance (TOC> 1%) are mainly distributed in the central part and subducted in the eastern part. 2 The sandstone reservoirs are mainly composed of quartz, feldspar, carbonate rock and clay. The content of quartz and feldspar is high, averaging 60%. The reservoir properties are poor with porosity and permeability less than 10% 1 × 10-3μm2, oil saturation between 10% and 60%, up to 70%; 3, the oil-bearing tight reservoirs are mainly distributed in the middle and lower parts in the longitudinal direction, There are four kinds of pore space types such as intragranular pores, intergranular pores, micro-fractures and organic pores. The first three types of pore seams are common in various minerals, while the latter are rarer. 4 The pressure coefficient of the lower part of Xinhe Formation is relatively high , Lighter in oil. The tight sandstone contains oil in intergranular pores, oil in dissolved pores, oil in intercrystalline pores and oil in microcracks. In the lower part of the Xinhe Formation in the Yabuli Basin, there are two favorable areas for tight oil exploration in the Xiaohu sub-depression and the Yanjia sub-depression slope. At present, the Xiaohu sub-depression has obtained a breakthrough in industrial oil flow and has a great potential for resources. For the next exploration favorable zone.