基于微观孔隙结构的特低渗储层分类评价方法——以大庆油田古龙南地区为例

为了搞清研究区不同区块油井产能差异,针对研究区属于低孔￣特低渗储层的特点,将表征储层微观孔隙结构特征的平均孔喉半径作为参数引入储层分类评价中,建立了基于测井曲线的平均孔喉半径解释模型。选取孔隙度、渗透率、平均孔喉半径及有效厚度作为储层评价参数,在单因素储层分类评价的基础上,采用模糊综合评判方法对研究区储层进行综合分类。将研究区各单元储层分为Ⅰ,Ⅱ,Ⅲ类,利用单井产能情况对储层分类结果进行检验。1类井初期日产油量为3.06 t,2类井初期日产油量为1.71 t,3类井初期日产油量仅为0.36 t。初期日产油量是由不同类型单井Ⅰ,Ⅱ类储层所占比例决定的,Ⅰ,Ⅱ类储层所占比例越大,油井初期产油能力越强。该储层分类方法为研究区后期各区块开发调整提供了重要依据。

Classification of extra-low permeability reservoir based on microscopic pore structure:a case study of South Gulong area in Daqing Oilfield

The average pore throat radius,which represents the microscopic pore structure characteristics of the reservoir,was introduced into the classification and evaluation of the reservoir as a parameter in order to find out the difference of production rate between different blocks in the study area,and an interpretation model of the average pore throat radius was established based on logging curve.Porosity,permeability,average pore throat radius and effective thickness are selected as reservoir evaluation parameters.Fuzzy comprehensive evaluation method is adopted to comprehensively classify the reservoir in the study area on the basis of single factor reservoir classification evaluation.The reservoir of each unit in the study area is divided intoⅠ,ⅡandⅢcategories,and the classification results of the reservoir are tested with the production rate of single well.Initial daily oil production of first-class oil wells is 3.06 t/d,second-class oil wells,1.71 t/d,and third-class oil wells,0.36 t/d.The difference in daily initial production of different types of wells is due to the difference of the proportion of different types of reservoirs.The larger the proportion of good reservoirs is,the more the daily oil production of oil wells is.The correctness of reservoir classification is verified,which provides an important basis for the development and adjustment of each block in the later period of the study area.