河控三角洲水下分流河道砂体储集层构型精细分析——以扶余油田探51区块为例

基于“模式拟合、动态验证”的研究思路,结合密井网区10口取心井、257口井测井资料及近10年的生产动态资料,对松辽盆地扶余油田探51区块泉四段扶余油层三角洲前缘水下分流河道储集层进行分析,探究水下分流河道储集层内部构型单元的空间展布特征及识别标志.结果表明:研究区目的层单河道砂体宽度为300~500 m,其识别标志分别为:河道间沉积、邻井砂体高程差异、河道砂体厚度差异、相邻砂体的“厚—薄—厚”组合;单河道砂体内部4级构型界面的倾角为0°~2°.明确了水下分流河道储集层中单河道砂体及单河道砂体内部增生体的测井响应特征及识别方法,建立了研究区目的层水下分流河道砂体的三维构型模型,为全区水下分流河道砂体解剖提供了定量、可靠的地质模式.图11表1参25

An in-depth analysis of reservoir architecture of underwater distributary channel sand bodies in a river dominated delta: A case study of T51 Block, Fuyu Oilfield

Studies were conducted on the dynamic processes of hydrocarbon migration and accumulation in the west part of the northern margin of the Qaidam Basin, based on previous studies on basin evolution and hydrocarbon system. Based on the dynamics of petroleum accumulation, basin analysis and the numerical stimulation method were applied to reconstruct the basin evolution. Simulation analysis of petroleum accumulation in the main reservoir-forming stages were conducted in the light of source rock properties in different stages, fluid potential field and physical property distribution of carrier beds. Controlling factors of reservoir formation in the northern margin of the Qaidam Basin were summarized. Studies showed that the Miocene is the main period of oil generation for the Jurassic source rocks in the studied area. The oil generation and migration volume were large. However, Saishiteng Sag was just on the slope in the northern part of Yiliping Sag. Structural traps were distributed at the margin of the basin. There was abundant oil migration to the north margin and a dissipation of the oil there during the later strong tectonic activities. During the late reservoir formation stage after the Pliocene, the source rocks generated mainly gas and not oil, and structural traps were well developed and provided good conditions for the natural gas reservoir formation. Deep structural traps in the basins were conducive to the formation of a large-scale low-permeability gas reservoir.