巴喀油田下侏罗统八道湾组沉积特征及油气地质意义

砂体作为油气优势储集介质,其展布特征直接影响油气运移最终归宿,层序地层格架作为控制砂体展布重要因素,具油气地质意义.通过对八道湾组层序地层与沉积特征进行系统分析,得到层序地层格架内砂体展布特征,预测研究区油气圈闭分布规律.研究表明,八道湾组整体经历了弱退积→强退积→进积过程,基准面上升期发育八二、三段,八三段分布于不整合面之上,易形成岩性油气藏.八二、三段分支河道砂在构造运动改造下,易形成构造油气藏与上倾尖火型岩性油气藏.基准面下降期发育八一段,其煤层既为生烃层,亦可作为储层,自生自储,可发育非常规类型煤层气藏.

Sedimentary Characteristics and Petroleum Geological Significance in BadaoWan Group of Baka Oilfield

Sand body,the preference media for oil and gas accumulation,its distribution character directly influences oil and gas migrating destination,stratigraphic framework is an important factor of sand body distribution.In this research,we analyzed stratigraphic and sedimentatary characters,and achieved sand body distribution characters for predicting oil and gas traps’ distribution finally.The findings indicate that the whole Badaowan Formation 2-3 sections of strata developed in the base level ascending cycle,Badaowan Formation 3 section distributed above on the plane of unconformity,developed the lithologica reservoir easily,Branch channel sand was transformed by tectonic movement,developed structural deposit and upward finger out lithologica deposit;Badaowan Formation 1 sections of strata developed in the base level descending cycle,coal was the section of hydrocarbon layer,but also the reservoir,coal-bed gas as the unconventional gas might be developed.