利用核磁共振可动流体评价低渗透油田开发潜力

采用核磁共振技术,对我国新疆小拐油田砾岩和砂岩、青海狮子沟油田灰质泥岩、大庆头台油田和长庆安塞油田砂岩等三种不同岩性的四个典型低渗透油田共165块岩心进行了可动流体评价研究。在此基础上,分析了低渗透油田可动流体与孔隙度、渗透率的相关关系,结合油田现场开发效果,发现可动流体百分数是评价低渗透油田开发潜力的关键物性参数之一,低渗透油田开发潜力的评价不应简单地直接采用中、高渗透油田所采用的评价方法,而应当综合考虑可动流体因素。还对低渗透油田可动流体的影响因素进行了分析研究,结果表明微裂缝发育程度、粘土充填孔隙程度及次生孔隙发育程度等微观孔隙结构特征是低渗透油田可动流体的主要影响因素。

THE EVALUATION OF DEVELOPMENT POTENTIAL IN LOW PERMEABILITY OILFIELD BY THE AID OF NMR MOVABLE FLUID DETECTING TECHNOLOGY

In this paper,the movable fluid evaluation and resear ch were made in 165 cores using nuclear magnetic resonance technique.The cores a re from four typical oilfields with low permeability in Xinjiang Xiaoguai,Qingh ai Shizigou,Daqing Toutai and Changqing Ansai oilfields and have three different lithologies.The correlations among movable fluid,porosity and permeability were analyzed.Combined with the oilfield development data,author found that the mova ble fluid parameter is a key factor for the evaluation of development potential in low permeability oilfield.The conventional methods used for development poten tial evaluation in middle or high permeability oilfields can't be simply applied to low permeability oilfields.The movable fluid should be considered as a neces sary factor.Factors affecting the movable fluid in low permeability oilfield wer e analyzed and studied in detail,and the results indicated that microstructures of pore such as micro-fracture,clay-filling and induced pore are the major fac tors that determine the movable fluid in low permeability oilfield.