柴达木盆地北缘块断带原油的地化特征及油源问题

GEOCHEMICAL CHARACTERISTICS AND PRO-VENANCES OF CRUDE OIL IN THE NORTHERN MARGINAL FAULTED BLOCK ZONE OF QAIDAM BASIN

罗铸金 汤锡元

Luo Zhujin Tang Xiyuan

西北大学

Northwest University

柴达木盆地北缘断层纵横交错,控制着本区的构造格局和中新生界地层的岩性和厚度,故称北缘块断带。其范围西起昆特依凹陷,东至旺尕秀地区,北界阿尔金山—祁连山山前断裂带,南邻葫芦山、埃姆尼克山一线,面积约三万平方公里(图1)。

Using the data derived from the analyses of GC, carbon isotopes and hydrocarbon groups, this paper studies the geochemical characteristics and possible provenance of crude oil in the northern marginal faulted block zone of Qaidam Basin. These studies indicate. 1.The J2d6 crude oil in Lenghu Area differs greatly from those in E3 and N1 formations and they are attributed to two different types. Together with another type of crude oil from Yuka-Lulehe, there are three types of crude oils in this area.The two types of crude oils in Lenghuare are resulted from different maturities of the source beds in different areas. 2.The J2d6 crude oil in Lenghu No.3 Area comes from J2d4-J2d5 source beds in the same area, bearing no relation with the source beds in Lenghu No.4 and 5 areas; while the crude oils producing from E3 and N1 in No.4 and 5 areas are not related to the source beds in No.3 Area. A part of the crude oils may derive from J2d4-J2d5 beds, the other part probably comes from an unknown source area. 3.The crude oils from Yuka and Lulehe may have the same provenance,i.e. from J2d6 and the underlying source beds bear no relationsh ip to J2d7 bed.

https://doi.org/10.11781/sysydz198602107