黄骅坳陷板桥油田板桥油层沉积特征及演化

渤海湾盆地黄骅坳陷板桥油田板桥油层沉积时期是黄骅坳陷断陷活动最强时期,湖盆迅速扩张使得盆地可容空间远大于沉积物补给,在油田的北区、中区形成了典型的深水重力流水道沉积,而南区受古地貌控制发育浅水滩坝沉积。通过岩心观察、相标志及测井相研究,在该区共识别出8种沉积微相。其中,重力流水道包括主水道、分支水道、水道侧翼和水道漫溢微相,滩坝沉积包括坝主体、坝侧缘、内缘滩和外缘滩微相。受湖盆扩张、沉积物源、古地貌及古气候等多种条件控制,垂向上沉积规模逐渐减小。沉积末期重力流水道仅在北区发育,弯曲分叉现象明显;南区滩坝沉积消亡。该区沉积特征及演化的精细研究,为进一步调整开发井网奠定了基础。

Sedimentary characteristics and evolution of the Banqiao reservoir in Banqiao oilfield, Huanghua Depression

The sedimentation of the Banqiao reservoir in the Banqiao oilfield occurred during the most active tectonism of the Huanghua Depression in the Bohai Bay Basin.The basin expanded so quickly that the accommodation space it provided was far more spacious for sedimentation.The typical deep-water gravity flow deposits were formed in the northern and central parts of the oilfield,while the shallow-water beach-bar deposits were formed in the southern part under the control of palaeo-geomorphology.Eight sedimentary micro-facies were identified in the study area through core observation and study of facies markers and logging facies.The gravity flow channel facies can be divided into 4 microfacies including main channel,distributary channel,channel flank and overflow.The beach-bar facies also can be divided into 4 microfacies,including main bar,bar flank,inner-margin beach and outer-margin beach.The sedimentary scale shrunk vertically due to many factors such as lake basin expansion,sediment input,palaeo-geomorphology and palaeo-climate.At the end of deposition,the gravity flow channel deposits were only developed in the northern part and the winding and forking phenomenon can be easily observed,while the beach-bar disappeared.The fine study of the sedimentary characteristics and evolutions in the area lays a sound foundation for adjustment of development well pattern.