低渗透性储集层评价方法及初产液量预测研究

Low-permeability reservoir evaluation methods and prediction for initial fluid volume production

低渗透性油气藏储集层孔隙极其微小,层内流体被毛细管力和黏滞力等束缚而难以流动,故其储集层评价和有效开发成为重要研究课题。可动流体是评价低渗透油气田开发潜力的重要岩石物性参数,通过核磁共振分析技术获取的可动流体与采油测试参数初产液量间的关系研究,建立了核磁共振可动流体储集层评价方法,将储集层划分为4类,相关系数为0.6027。为进一步定量评价储集层,引入评价参数P,进行初产液量预测,把可动流体、孔隙度评价数据直接与初产液量拟合,提出了计算模型与校正方法以及相关系数求取方法。通过在镇泾油田延长组储集层评价的应用实例表明,该方法能够现场随钻预测储集层初产液量,对油气层进行有效评价,提高解释精度,为完井方案的确定、测试选层、制定早期开发方案提供技术支持。

In low permeability reservoir,the pore is extremely small,stratified fluid is difficult to flow due to the binding of capillary force and viscous force,so the reservoir evaluation and effective development has become the important subject of study. Movable fluid is one important parameter of rock physical properties which is used to evaluate the development potential for low-permeability oil-gas field. Through studying the relations between the movable fluid obtained from NMR analysis and initial fluid volume of oil production test,the NMR evaluation method for the movable fluid reservoir was set up,the reservoirs were divided into 4 types,and correlation coefficient is 0.6072. In order to further quantitatively evaluate reservoirs,the evaluation parameter P was used to make prediction of initial fluid volume production,the evaluation data of the movable fluid and porosity were directly fitted with initial fluid volume production,and the absolute correlation coefficient reaches 0.9484. The applied results in reservoir evaluation of Yanchang Group in Zhenting Oilfield indicated this method could be used to predict the on-site initial fluid volume production while drilling,effectively evaluate hydrocarbon reservoirs,increase the interpretation accuracy,and provide technical support for determination of completion program,selection of test layer and production of the early development programs.