摘要
大庆油田北三区上白垩统葡一油层组以高频湖进面可划分为3个四级和8个五级的高精度层序地层单元。以密集开发井资料为基础追踪这些层序单元可为储层砂体研究提供精细的等时对比框架。该油层组的主要储集砂体多为复合型砂体,由各种单一砂体相互叠置和切割所形成,包括下切河道(谷)分流河道复合砂体、水下分流河道上叠水上分流河道复合砂体、分流河道上叠河口坝砂体、决口水道上叠决口三角洲砂体等复合类型。这些砂体的内部沉积构成复杂,控制着厚油层储层物性的非均质性变化。在高精度层序框架内可划分出3个砂体复合带,其沉积构成的差异对剩余油的分布具有重要影响。主河道复合砂体带的孔渗性和连通性好,易形成上部层内和隔层非均质性剩余油;河道边部-河口坝复合砂岩带结构复杂,隔层发育,易形成平面未波及或物性变化导致的剩余油,应是区内剩余油挖潜的重要相带;边缘砂坝-决口扇-越岸泛滥砂泥岩互层带砂体分布局限,孔渗性和连通性差,由于井网控制不够或连通性差形成剩余油。
Pu-1 oil layer of the Upper Cretaceous in the third northern development district of Daqing Oilfield, can be divided into three 4th order and eight 5th order high-resolution sequences, in terms of lacustrine flooding surface. Correlation of these stratigraphic units based on densely-spaced borehole data provides a high resolution correctable stratigraphic framework for the study of the architecture of the reservoir sandbodies. Most of the major reservoir sandbodies are composite sandbodies formed by amalgamation or superimposition of single sandbodies, and include the incised valley-distributary channel, distributary channel superimposed subaqueous distributary channel, distributary channel superimposed delta front mouth bar, crevasse channel superimposed crevasse delta or marginal sand bar composite sandbodies. The complex of the facies architecture of the sandbodies determines the reservoir inhomogeneity of the oil layer. Within the high-resolution sequence stratigraphy framework, three composite sandstone belts have been classified, and their the remaining oil distribution. The main fluvial channel depositional architectures had a significant influence on composite belts are of high porosity, permeability and connectivity, with remaining oil mainly formed by the inhomogeneity of the upper intrabed and obstruct layer. The marginal fluvial channel-mouth bar belts are characteristic of complex amalgamation of sandbodies with more inter obstructs, and the remaining oil are commonly formed by inhomogeneity of the sandbodies with poor permeability and dispreaded areas in development. This is the important facies zone for prediction of remaining oil in the oil field. The marginal sandy bar-crevasse and flooding interbeded fine belt are characterized by limited sandstones and poor permeability, with remaining oil often formed by deficient borehole network or poor connectivity.
出处
《现代地质》
CAS
CSCD
北大核心
2006年第2期225-231,共7页
Geoscience
基金
国家"973"项目(G1999043304)
关键词
高精度层序格架
复合砂体沉积构成
剩余油分布
葡一油层组
大庆油田
high-resolution sequence framework
composite sandbody architecture
remaining oil distribution
Pu-1 oil layer
Daqing Oilfield
