彭阳-镇北地区长8段沉积特征研究

Sedimentary characteristics of Chang 8 member in Pengyang-Zhenbei area

在对彭阳-镇北地区区域构造、沉积背景进行调研的基础上,利用轻矿物、重矿物、野外剖面流向实测资料、重点井磁组构古水流测试等资料分析了长8期物源方向,认为长8期研究区主要物源来自西南方向;利用野外露头、钻井岩心、测井等资料,对研究区的沉积相特征及演化进行研究,在长8期识别出冲积扇、辫状河三角洲沉积,对沉积亚相和微相进行了划分,并提炼总结了研究区骨架砂体常见的六种沉积模式,其中辫状河道连续沉积和辫状河道连续叠置形成了研究区油气储层重要的物质基础。

Based on the investigation of regional structure and sedimentary background in Pengyang-Zhenbei area,the source direction of Chang 8 phase was analyzed by using the measured data of light mineral,heavy mineral,field profile and paleo-flow test of magnetic structure in key wells.It is believed that the main source direction of Chang 8 phase was from the southwest direction.Based on the data of outcrop,drilling core and well logging,the characteristics and evolution of sedimentary facies in the study area were studied.Alluvial fan and braided river delta deposits were identified in Chang 8 phase.Sedimentary subfacies and microfacies were divided.Six common sedimentary models of skeleton sand bodies in the study area are summarized,among which the continuous deposition of braided channel and the continuous superposition of braided channel form the important material basis of oil and gas reservoirs in the study area.