大庆油田二类油层注聚对象的确定及层系组合研究

Research on polymer flooding object and layers combination for sub-mainlayers in Daqing oilfield

应用密闭取心井资料、葡I组主力油层工业化注聚区块和二类油层注聚先导性试验区的资料,并结合室内物模实验和数值模拟研究,确定二类油层主要注聚对象为河道砂和有效厚度大于1m的非河道砂,有效渗透率下限为0.1μm2;考虑聚驱二类油层的地质特点、渗透率级差对聚驱效果的影响、聚驱二类油层井网与水驱井网的相互影响、地面注聚系统的规模和产量衔接、注入强度、经济效益等因素,制定的聚驱二类油层层系组合的原则为:一套层系内聚驱单元相对集中,地质条件接近,渗透率级差小于3;层系间厚度要求尽量均匀,一套层系最小厚度8m左右;具体单元具体对待,采取不同的开采方式,以限制注聚对象,减小层间矛盾。最后对萨中以北地区31个区块进行了层系组合研究。

Applying airtight core data,field experiment data of the sub-mainlayers and practical data of Pu I group industrialized polymer flooding,combine with physical simulation and numerical simulation method,this paper confirms the primarily polymer flooding object of sub-mainlayers,that is channel sand and non-channel sand that availability thickness upwards of 1 m, and the availability permeability is more than 0.1μm 2.According to the oil reservoir characteristic,permeability heterogeneity,water flooding well pattern, production scale,equipment usage,injection velocity, economic efficiency and so on,this paper constituts the layers combination principles of sub-mainlayers polymer flooding:the units must concentrate relatively in one series of layers,and the geologic condition is close to each other,the permeability ratio is less than 3,the thickness from two series of layers should be well-distributed and the smallest thichniss is about 8 m. In fact,any specific unit must be put special researches and applying different flooding methods in order to limit the object and reduce the interlayers interference. Finally it completes for 31 blocks north of Sazhong area to assemble the series of layers.