摘要
利用毛细管压力曲线对鄂尔多斯盆地姬塬地区长8低渗透储层孔隙结构定量分类,研究各类孔隙结构与测井响应特征的关系,引入自然伽马曲线的变异系数,建立测井曲线表征孔隙结构的方法,并制作了孔隙结构测井识别图版。该区长8储层孔隙结构分为3类,第1类毛细管压力曲线有2段平缓段,物性好,孔隙结构非均质性中等,自然伽马曲线变异系数平均值为3.4;第2类毛细管压力曲线存在一段较长平缓段,物性中等,孔隙结构非均质性弱,自然伽马曲线变异系数平均值为1.85;第3类毛细管压力曲线基本无平缓段或者平缓段较短,物性差,孔隙结构非均质性强,自然伽马曲线变异系数平均值为6.14。由此建立了低渗透储层孔隙结构常规测井识别的方法,与非常规测井表征孔隙结构的方法相比,该方法成本低,易广泛应用。基于孔隙结构连续表征,能够进行储层分类评价。
By means of capillary pressure curves,the pore structures of low-permeability sandstones in Chang 8oil layers in the Jiyuan region,Ordos basin,were examined to evaluate by classification.On this basis,We investigated characteristics of conventional log responses to different kinds of pore structures and proposed a method to identify pore structures by coefficient of variation of natural gamma ray log curves,and established a corresponding identification chart for pore structures in reservoirs.Three types of pore structures in the investigated region were classified:type 1 pore structure with the best macroscopic quality showed moderate heterogeneity,and its average coefficient of variation of natural gamma ray log curves was 3.4;type 2pore structure with the moderate macroscopic quality showed comparative homogeneity,and its average coefficient of variation of natural gamma ray log curves was 1.85;type 3with the worst macroscopic quality showed strong heterogeneity,and its coefficient of variation of natural gamma ray log curves was 6.14.Above all,we can continuously identify pore structures according to conventional logs,this method is economic and easy to be widely used compared to the method of identifying pore structures by unconventional logs.By means of this identification method,reservoir can be evaluated and classified.
出处
《测井技术》
CAS
CSCD
2016年第2期175-179,共5页
Well Logging Technology
关键词
测井解释
低渗透砂岩
孔隙结构
毛细管压力曲线
变异系数
储层分类
log interpretation
low-permeability sandstone
pore structure
capillary pressure curve
coefficient of variation
reservoir classification
