低渗透油藏油水赋存状态研究

Study on occurrence state of oil and water in low permeability reservoir

为了得到低渗透油藏岩心水驱油以及油驱水过程中可动流体的分布情况,通过核磁共振技术实验,对不同渗透率水平的储层进行核磁共振T2波谱特征形态分析,观察T2波谱形特征与渗透率之间的关系,得到岩心的可动流体饱和度;通过对剩余油分布情况的统计分析,得出岩心中的剩余油主要分布在0.1~10.0μm的孔隙中,占总分布量的85%以上,表明后期挖掘剩余油的主要空间主要是中小型孔隙。通过对不同渗透率级别的岩心进行水驱油实验,得出在1.8 MPa/m的压力梯度下进行驱油有较好的效果并确定出最佳驱油压力梯度,明确了压力梯度对微观赋存状态的影响。研究可为DB油田措施挖潜和稳产技术研究提供指导。

In order to obtain the distribution of movable fluids in the core water drive and oil drive water process of low permeability reservoirs,through nuclear magnetic resonance technology experiments,the characteristic morphology of nuclear magnetic resonance T2 spectrum of reservoirs with different permeability levels were analyzed to observe the T2 The relationship between the spectral shape characteristics and permeability to obtain the movable fluid saturation of the core;through the statistical analysis of the remaining oil distribution,it was concluded that the remaining oil in the core was mainly distributed in the pores of 0.1~10.0μm.It accounted for more than 85%of the total distribution,indicating that the main space for the later excavation of remaining oil is mainly small and medium pores.Through water flooding experiments on cores with different permeability levels,it was concluded that oil displacement under a pressure gradient of 1.8 MPa/m had a good effect and the optimal displacement pressure gradient was determined,and it was clear that the pressure gradient had a microscopic effect.The impact of the state of existence.The research could provide guidance for DB oilfield measures to tap potential and stabilize production technology.