摘要
泥质含量(V_(sh))的合理预测对其他储层参数预测、钻探设计及井壁稳定性评价等方面均有一定影响,但常规岩石V_(sh)预测方法的评价效果通常欠佳。基于该现状,以川西地区上三叠统致密碎屑岩储层为例,通过设计实验及测井参数提取,分别采用常规自然伽玛法、三孔隙度模型及因子分析方法对储层泥质含量进行评价预测,并与实测结果进行对比。研究结果表明,自然伽玛法的平均相对误差为27%,该方法主要会造成致密砂岩的V_(sh)出现显著偏高。三孔隙度模型的平均相对误差为6%,误差较小。因子分析方法综合考虑了自然伽玛、中子孔隙度、纵波时差、岩石密度、电阻率、自然电位及有效孔隙度7个参数,岩样尺度因子(F_1′)与V_(sh)间具有较好的幂指数关系,待定常数m=2.368,n=0.040。该方法的平均相对误差为4%,预测效果最好。综合来看,因子分析方法最适用于该地区陆相致密碎屑岩储层V_(sh)的预测。
Reasonable prediction of shale content （Vah） affects the reservoir parameter predic- tion,drilling design and evaluation of borehole stability. Based on the designing experiments and extraction of logging parameters, the natural gamma method, three porosity models and factor a- nalysis method are used to predict shale content of the clastic reservoir of Upper Triassic Xu5 sec- tion,in the western Sichuan Basin and to compare the calculated results with the measure results. It shows that the average relative error of the gamma method is 27% and this method can greatly increase the error of V,h for tight sandstone,while the average relative error of the three porosity model is small （only 6%）. For the factor analysis method, it takes the effect of natural gamma, neutron porosity, and longitudinal wave time difference, rock density, and resistivity, natural po- tential and effective porosity on the shale content as consideration. It shows that there is a good exponential relationship between the scale factor （F1） and Vsh,with the constant m=2. 368,n= 0. 040,and it gets the best prediction effect with average relative error of 4%. Therefore, the fac- tor analysis method is the most suitable one for the predition of shale content of the continental tight clastic reservoir in this area.
出处
《矿物岩石》
CAS
CSCD
北大核心
2017年第4期110-116,共7页
Mineralogy and Petrology
基金
国家科技重大专项课题(2017ZX05009-002)
关键词
致密碎屑岩
泥质含量
预测方法
tight clastic rock
shale content
predicting method
