鄂尔多斯盆地彬长地区长8段砂质碎屑流沉积及储层特征

Sandy clastic flow deposition and reservoir characteristics of Chang-8 formation in Binchang area, Ordos basin

近几十年来,随着对鄂尔多斯盆地三叠系延长组致密储层油藏勘探开发的不断深入,储层特征刻画在油气有利区预测中的作用日益凸显。长期以来,以三角洲模式解释彬长地区长8段与实际钻探情况及取心资料存在诸多出入,随着深水重力流沉积理论的逐步深入,彬长地区长8段沉积特征与砂质碎屑流沉积特征模式极其相符。以深水重力流沉积理论为指导,综合岩心、测井及分析化验资料,分析彬长地区长8段沉积特征,认为该区发育深水重力流沉积,主要沉积类型为砂质碎屑流,少量浊流及滑塌沉积,并在此基础上对比描述不同沉积微相类型储层的特征及含油性差异,从而为有利区预测提供指导。

In recent decades, along with the further exploration and development of dense reservoir of Yanehang formation in Trias- sic, Ordos basin, reservoir characterization plays an increasingly important role in the prediction of oil and gas favorable area. For a long time, in Chang-8 formation of Binchang area, it exists unconformity among the explanation based on delta model, the actual drilling situation and core data. As the gradually development of deep-water gravity flow deposits theory, the sedimentary character- istics are consistent with sandy clastic flow deposition characteristics model. Guided by deep-water gravity flow deposits theory, based on core, logging and testing data, sedimentary characteristics of Chang-8 formation in Binchang area were analyzed. We con- sider that deep-water gravity flow deposits are developed in this area. Sandy elastic flow, a small amount of turbidity flow and slump deposits are the main sedimentation types. On this basis, this paper compared the description of features and oiliness differ- ences of different sedimentary microfacies reservoir, thereby providing guidance for favorable area develooment.