湖北省广北油田潜三段下部湖底扇沉积特征分析

Analysis on Sedimentary Characteristics in Lower Reach of Third Section of Qianjiang River in Guangbei Oil Field,Hubei Province

从区域地质背景出发 ,结合岩心观察、粒度分析、镜下鉴定结果及测井曲线形态等进行综合分析表明 ,位于蚌湖向斜东南斜坡的湖北省广北油田Eq341沉积时属半深湖—深湖背景下的湖底扇相沉积 ,可细分为内扇、中扇和外扇 3个亚相 ,其中中扇可细分出辫状沟道、辫状沟道间和扇中前缘 3个微相。根据测试资料分析 ,有辫状沟道的中扇为有利相带 ,指出蚌湖向斜东南斜坡、钟市陡坡三角州前缘是寻找油藏的有利区带。

Basing on regional geological background, combing with bore core investigation, grading analysis, optical determination result and log curve style, Guangbei oil field is analysed in this paper. Eq3 4 1 sedimentary which locates in southeast shelving of Buhu downfold belongs to sublacustrine fan facies with the background of semi-deep-deep lake. It can be further divided into three subfacies as inner fan, middle fan and outer fan. Middle fan can be further divided into three microfacies as braid canal, plain areas between braid canals and front edge of inner fan. Using drilling and seismic information, space combination and plain distribution characteristics of this fan are described in this paper, and origin is analysed as well. Combing with determination information, middle fan with braid canals is useful facies belt, and useful areas developing this kind of fan belt are pointed out, which indicate the direction for exploration of property.