柴达木盆地北缘地区第三系碎屑岩储层沉积相特征

柴达木盆地北缘地区是青海油田三大产油气区之一。该区第三系碎屑岩储层主要分布于下干柴沟组(E3)到下油砂山组 (N12 )地层中 ,前人认为此地层主要以河流相和泛滥平原相为主。对该地区的地面、井下岩性和岩相进一步研究表明 ,自下干柴沟组至下油砂山组的储集砂体主要为滨—浅湖滩坝亚相和湖泊三角洲相。这一结论对正确估算柴北缘地区的第三系油气储量及促进青海油田的增储上产具有重要的意义

CHARACTERISTICS OF TERTIARY RESERVOIR SEDIMENTARY FACIES IN THE NORTH PART OF QAIDAM BASIN

The north part of the Qaidam basin is one of the three oil|bearing units in Qinghai oilfield. The Tertiary reservoirs are mainly distributed in the strata from low|Gancaigou formation to low|Youshashan formation. The former research on Tertiary sedimentary facies determined that fluvial and flood plain are the main facies. A comprehensive study on petrology, structures, facies models, facies associations and sedimentary systems in this paper shows that the main facies in Tertiary are shore|lake and shallow|lake subfacies, and lake delta facies from low|Gancaigou formation to low|Youshashan formation. This new conclusion is very important in theory and economics during the course of calculating the geological reserve of Tertiary.