河流相储层剩余油分布控制作用研究

Distribution Control for Residual Oil in Fluvial Facies Layer

以港东一区一断块东检5井区为研究对象,精细分析了剩余油形成和分布的控制因素,总结了剩余油分布模式。结果表明,导致剩余油复杂不均一的根本原因是油藏地质因素和开发工程因素的非耦合性,如河道沉积多为较高渗透性,而溢岸沉积则为较低渗透性;河道砂体采出程度高于溢岸砂体,级差增加,采收率下降。认为平面上剩余油分布在储层砂体相对薄而差的溢岸、决口水道、废弃河道等砂体部位;对开发因素形成的剩余油,包括井网控制不住形成的剩余油、渗流分隔性产生的剩余油和注采井网与井点的非耦合性形成的剩余油而言,在不改变已有井网的条件下,注水波及范围难以得到明显改善。

In this paper,we discuss the controlling factors about formation and distribution of remaining oil in the Dj5 well in one block of Gangdong as a case,and summed up the distribution model of remaining oil for tapping the potential of remaining oil to provide the necessary technical support.The result indicated that a complex and uneven distribution of residual oil would be made by non-coupling action between reservoir geology and development engineering.Differences between layers display the higher permeability for multi-channel deposits but the lower permeability for overflow deposits.The production of petroleum from the channel sand body is higher than that from overflow shore sand body,with differential increase and recovery decrease.The residual oil is distributed in the sand reservoirs of thin and poor overflow shore,crevasse channel,abandoned channel sand body parts,etc.The formation of remaining oil during development process includes the well network,seepage separation,non-coupling action between injection-production well network and well point.It is difficult to limit the sweep area under no change of well network.