It is very risky and difficult to develop low-permeability reservoirs, but reservoir development can be guided by the development potential of different low-permeability reservoirs. In this study, natural cores of the Daqing Oilfield were used as the research objects. The throat radius distributions of the different low-permeability cores were determined by the constant velocity mercury injection method, the movable fluid distribution characteristics were determined by nuclear magnetic resonance, and the nonlinear fluid flow characteristics were analyzed via fluid flow experimentation. From these data, the development potential for low-permeability reservoirs was determined. The results show that when the permeability is , the average throat radius is only approximately 0.9 μm and throats with radii less than 0.1 μm account for approximately 30% of the throats. The throats with an average radius less than 1 μm, especially throats with radii less than 0.1 μm, are the main factor restricting the fluid flow in these cores. The movable fluid is only approximately 20% of the fluid in a core, and the threshold pressure gradient reaches 0.15 MPa/m when the permeability is , indicating that it is more difficult to develop reservoirs with permeabilities less than .

中文翻译：

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大庆油田低渗透油藏开发潜力试验研究

开发低渗透油藏风险很大，难度很大，但可以根据不同低渗透油藏的开发潜力来指导油藏开发。本研究以大庆油田天然岩心为研究对象。采用等速压汞法确定不同低渗透岩心的喉道半径分布，核磁共振确定可动流体分布特性，通过流体流动实验分析非线性流体流动特性。根据这些数据，确定了低渗透油藏的开发潜力。结果表明，当渗透率为 时，平均喉道半径仅为 0.9 μm 左右，半径小于 0 的喉道。1 μm 约占喉部的 30%。平均半径小于 1 μm 的喉道，尤其是半径小于 0.1 μm 的喉道，是限制这些岩心流体流动的主要因素。可动流体仅占岩心流体的20%左右，渗透率为0.15 MPa/m时的临界压力梯度达到0.15 MPa/m，表明渗透率小于0的储层开发难度更大。