克拉玛依油田七中东区克下组沉积微相及演化

Sedimentary Microfacies and Evolution of the Lower Karamay Formation in mid and east of 7th Block,Karamay Oilfield

通过对区域地质背景、岩心相、测井相分析,并结合分析化验等资料,认为克拉玛依油田七中、东区克下组沉积相为山麓-洪积相.将本区划分为扇根内带、扇根外带、扇中和扇缘4个亚相.从下到上,克下组沉积相平面分布从以扇根砂砾岩为主,演化为以扇中砂砾岩与泥岩互层为主,最终转变为扇缘泥岩夹少量砂砾岩.划分了槽流砾石体、片流砂砾体、漫洪砂体、漫洪细粒沉积、辫流水道、径流水道、漫流砂体和漫流细粒共8个沉积微相,描述了各微相岩石学特征、结构特征、构造特征和电性特征,指出沉积相平面展布及垂向演化特征,建立了研究区沉积模式.

In mid and east of 7th block,Kararnay Oilfleld,the sedimentary characteristics of the Lower Karamay Formation were not recognized clearly, which impressed exploiting the remaining oil and deploying the plan. Through the analysis of depositional environment, core facies and electrofacies,it is concluded that piedmont pluvial facies were developed during the deposition of the Lower Karamay Formation. On the basis of this area, four subfacies were divided（the inner belt of root fan, the outer belt of root fan, middle fan and fan edge）.In bottom section of formation, the glutenite of root fan is dominant in the facies distribution of plane; In middle section, the glutenite of middle fan interbed mudstone is dominant; In top section, the mudstone intersperse with glutenite is predominant. Based on the piedmont pluvial facies, eight microfacies were divided（the gravel of channel flow, the gravel of laminar flow, sheetflood sand, sheetflood fine grain, braided chamnel, runoff channel, overflow sand and overflow fine grain）. And the characteristics of petrology, construction, structure and electric were described. The distribution of facies in plane and certical evolution were indicated, and the sedimentary model of the area was established.