摘要:
通过 15口井近百个铸体片的鉴定及压汞数据的分析,对跃进地区E31、N1、N21碎屑岩储层取得如下认识 :①长石砂岩、岩屑长石砂岩、长石岩屑砂岩为主,成分成熟度和结构成熟度均较低;②储层经历压实压溶作用、成岩自生矿物胶结和溶解作用,剩余原生粒间孔占绝对优势,相同层位地层在跃东和跃西因埋藏深度不同导致成岩—孔隙演化史也不同,西区储层物性明显优于东区;③储层主要发育于水上分流河道、砂坪和辫状河道微相,碎屑的成份和结构成熟度、填隙物含量、成岩环境对储层性质有重要影响;④西区E31储层属高孔中渗的Ⅱ类储层,大孔细喉道组合特征,储集物性较佳,东区E31储层属特低孔特低渗的Ⅴ类储层,中孔微细喉道组合特征,储层物性不理想,N1储层属低孔特低渗的Ⅳ—Ⅴ类储层,大孔小喉道组合特征,渗透率不佳.
Abstract:
More attention has been paid to the report of hvdrocarhon from E31、N1、N21 clastic rock reservoir in Yucjin area Qaidam hasin, northcrnwcst China. Based on research of approximate one hundred cast thin sections and mcrcurv intrusion curve from 15 wells, some results on E31、N1、N21 elastic rock reservoir in Yuejin area have been obtained.as follows:①The elastic rock reservoir was composed of fcldspathic sandstone } lithic arkosc and fcldspathic litharcnitc which is characterized by lower composition and texture maturity②The elastic rock reservoir has undergone compaction, pressure dissolution, authigcnc(fcrroan calcite, dolomite, anhydrite, cuthalitc, fcrroan dolomite pyrite ) ccmcntation and dissolution, which results in the forming of overwhelming relic primary intcrgranular pore.Corrclatahlc beds from eastern Yucjin and western Yucjin have different diagcnctic-porosity evolution because of their different burial depths which results in a more favourable reservoir in western Yucjin than in eastern Yuejin,③E31、N1、N21 elastic rock reservoir developed under distrihutarv channel sand flat and braided channel microfacics.Reservoir quality was controlled by composition and texture maturity, matrix material and diagcnctic environment}depth especially),④E3, elastic rock reservoir from western Yucjin characterized by very large, large and medium pore,Ⅱ-grade( high porosity and medium permeability ) in reservoir quality and a combination of large porefine throat while E3 elastic rock reservoir from eastern Yucjin did large and medium pore,Ⅴ-graded (very low porosity(very low permeability) in reservoir quality and a combination of medium pore-very fine throat. N1 elastic rock reservoir in Yucjin area characterized by very large large and medium pore,Ⅳ-andⅤ-grade( low porosity and very low permeability) in reservoir quality and a combination of large pore-very fine throat.