桩89井区沙二段沉积微相与油气关系

通过岩石相分析，综合电性特征及砂体的空间分布，对桩西油田桩89井区沙二段沉积微相特征及其空间展布进行了分析，查明了沉积微相类型与含油性的关系。认为桩89井区沙二段地层为一套湖泊沉积体系，包括滨湖砂坝、湖坪、生物滩、浅湖砂坝、浅湖泥等微相，其中滨湖砂坝与生物滩微相的储集层含油性最好。

Reservoir Forming Rules of Guantao Formation in Shuyi Region of Shuguang Oilfield

The geologic characteristics of heavy oil and ultra-heavy oil reservoirs in Guantao Formation of Shuyi region in Shuguang Oilfield are described.The mechanism and control factors of the reservoir formation are found out,it is considered that the reservoir is a self-condensate reservoir,where oil is from overlying Xinlongtai layer.In the process of the oil migration and reservoir forming,it experiences water flushing,therefore its viscosity increases,condensate point reduces.Because the temperature of its condensate points is higher than that of formation,thus reservoir is formed from the asphaltic-shell trap caused by self-condensate,while its distribution is controlled by source position,oil density,oil consistency and its condensate point.