利用恒速压汞技术,对牛圈湖油田西山窑组低渗透油藏孔隙结构和渗流特征进行研究。恒速压汞实验通过检测汞注入过程中,压力涨落不仅能够得出喉道和孔隙各自的发育情况,而且能够给出喉道和孔隙的大小及其分布特征。实验表明喉道是控制低渗透、特低渗透油藏储层性质的决定因素。储层主流喉道分布的微观非均质差异是渗流能力非均匀性的重要原因。通过与同类型油田对比得出,相同渗透率级别的岩心,牛圈湖西山窑组油藏喉道半径往往比大多油田小,这就决定了牛圈湖油田开发难度大的原因之一。 The pore structure and seepage characteristics of low permeability reservoirs in Xishanyao Formation of Niuquanhu Oilfield were studied by constant pressure mercury intrusion technique. Constant pressure mercury intrusion test can detect not only the development of throat and pore, but also the size and distribution of throat and pore. Experiments show that the throat is the decisive factor for controlling the reservoir properties of low-permeability and ultra-low permeability reservoirs. The micro-heterogeneity of the main throat distribution in the reservoir is an important reason for the heterogeneity of seepage capacity. By comparing with similar oilfields, it is concluded that the radius of the throat of the Xishanyao Formation in Niuquan Lake is smaller than that of most oilfields in the core of the same permeability, which determines the difficulty of the development of NiuShuHuang oilfield.