四川盆地洛带气田遂宁组Jsn1^1-2砂体对比及沉积微相研究

Sandbody Distribution and Sedimentary Micorfacies of the Upper Jurassic Suining Formation Jsn_1^(1-2) in Luodai Gasfield

洛带气田遂宁组属于浅水三角洲沉积,沉积主体以三角洲前缘沉积为主。运用地震资料精细标定及识别砂层组,结合多井测井曲线解释成果,建立砂体对比格架,运用井震资料互馈结合,一致性对比的原则,开展砂体对比,分析遂宁组Jsn_1^(1-2)砂组的沉积微相展布及砂体对比情况。研究结果表明,洛带气田遂宁组Jsn_1^(1-2)砂组处于三角洲前缘亚相,沉积微相有水下分流河道、分流间湾、河口坝、水下决口扇,遂宁组Jsn_1^(1-2)组有10条分流河道,分布不均匀,决口扇位于分流河道的两侧,河口砂坝出现在分流河道末端。砂体的展布明显受控于沉积微相,分流河道微相砂体厚度较厚,河口砂坝与决口扇微相砂体厚度较薄。该方法对横向变化快、砂体对比难度大的储层研究有着重要的意义。

The sedimentary facies of Suining formation belongs to the shallow water delta. The subfacies of Suining Formation is deltaic fornt. Seismic data were used to fine calibrate and recognize the sand layer, combined with logging interpretation results, the sandbody correlation framework was established. Based on consistent comparison principle, sandbody comparison was carried out,Suining Formation Jsn1^1-2 sand deposition microfacies distribution and sandbody comparison were analyzed.The results show that Suining Formation Jsn1^1-2 sand is in delta front subfacies, sedimentary microfacies includes underwater distributary channel, channel mouth bar, interdistributary estuary in delta front, crevasse splay in Luodai Gasfield; Suining Formation Jsn1^1-2 group has 10 distributary channel, crevasse splay located in distributary channel flank, the interdistributary estuary in distributary channel at the channel mouth. The sandbody distribution is subjected to sedimentary microfacies. The sand bodies of the distributary channel microfacies have relatively thickness. The sandbodies of estuarine sand bar and crevasse splay microfacies have very limited thickness.