三角洲前缘滑塌型重力流沉积特征及控制因素 ——以松辽盆地大安地区青一段为例

重力流砂体是烃源岩内生储组合的重要部分,具有较大的勘探开发潜力.综合利用岩心、三维地震、粒度分析、测井及录井资料,结合区域地质背景,系统分析了松辽盆地大安地区青一段三角洲前缘滑塌型重力流类型、识别标志、沉积特征、形成及分布控制因素和勘探开发潜力.结果表明:研究区青一段主要发育滑动-滑塌、砂质碎屑流及浊流3种滑塌型重力流...

Sedimentary characteristics and controlling factors of slump gravity flow in delta front:a case study of Qing 1 member in Da'an area,Songliao Basin

Gravity flow sand body is an important part of the source-reservoir assemblage in source rocks and has great potential for exploration and development.Based on the data of cores,3D seismic,grain size analysis,wire-logging and mud-logging,combined with regional geological background,the types,identification marks,sedimentary characteristics,formation and distribution controlling factors,and exploration and development potential of slump gravity flow in delta front of the first member of Qingshankou Formation in Da'an area of Songliao Basin were analyzed systematically.The results show that there are three types of slump gravity flow developed in Qing 1 member in the study area,including sliding-slump,sandy debris flow and turbidity flow,which are distributed adjacently or alternately distributed in the vertical direction,and evolve sequentially in the plane.Slope break zone and base level change have a controlling effect on the formation and distribution of these three types of gravity flow.Sliding-slump,sandy debris flow and turbidity flow are distributed at the foot of slope,slope and basin plain,respectively.The sandy debris flow shows different sedimentary characteristics and fluid properties during base level rising and falling period.The base level rising period is a favorable period for the development of gravity flow sand body,and the sandy debris flow is distributed in a sheet shape,with completely developed gravity flow sedimentary sequence.In the early stage of base level falling,the distribution of gravity flow sand bodies is relatively restricted,and the sandy debris flow shows a river channel distribution pattern that is of dual fluid properties of traction flow and gravity flow.The sandy debris flow and turbidite sand layer are relatively thin and often associated with lacustrine source rocks to form lithologic traps,and the single well production often tends to be higher.