大牛地气田上古生界低渗储层综合评价

Comprehensive Evaluation of Lower Porosity and Permeability Reservoir in Upper Paleozoic of Daniudi Gas Field

大牛地气田上古生界山1段至盒3段为典型的低孔低渗储层,但各段的储集性能仍存在一定差别。因此,从沉积相、岩石学、成岩作用、孔隙度、渗透率等方面对其进行系统分析,表明山1段至盒3段沉积体系由三角洲相向河流相逐渐演变;储层成岩作用较强,尤其压实作用破坏原生孔隙严重,山1段至盒3段压实作用及溶蚀作用逐渐减弱;孔隙度、渗透率较低,但山1段至盒3段呈增加趋势。最后,根据沉积相、成岩作用、孔渗特征、孔隙类型等建立适合研究区的评价标准,并进行综合评价。结果表明,盒3段、盒2段储集性能最好,其次是山1段,而盒1段、山2段最差。

The Shan 1-He 3 member of the Upper Paleozoic in Daniudi Gas Field is a typical lower porosity and permeability reservoir, but the differences of reservoir properties exists in each member. This paper analyzes reservoir of the Upper Paleozoic from the aspects of sedimentary facies, diagenesis, character of porosity and permeability, pore type and structure etc. The result shows that the sedimentary system from Shah 1 to He 3 member changes gradually from delta facies to fluvial facies; reservoir diagenesis is strong and the compaction damages the primary pore seriously. Compaction and dissolution from Shan 1 to He 3 member weakened. Both porosity and permeability are poor, but are increasing from Shah 1 He 3 member. Finally, the authors set up the evaluation standards based on Sedimentary facies, diagenesis, porosity and permeability characteristics, pore type, etc. and give out a comprehensive evaluation. The result shows that He 3 and He 2 members are the best of reservoir performance, followed by Shan I member and He 1 and Shan 2 are the worst.