Abstract:

The Longshen 1 well marks the breakthrough for deep gas exploration in the Yingtai depression in southern Songliao basin, and the ascription of its deep horizon is a key to the resource evaluation and reserve prediction in the Yingtai depression. The deep horizons in  the Longshen 1 well were further subdivided by using rock-electric characteristics, correlation between wells, sporopollen assemblages and log and seismic data. The generalization is as the followings: the Yingcheng Group of the Longshen 1 well consisting of two set of thick volcanic (igneous rock) and two set of thin sedimentary rocks. They are significantly different from both the underlying and overlying layers in lithology, electrical property and seismic features. Its sporopollen characteristics were also distinct to those of the upper and lower formations, with gymnospermae pollen being up 65% and pteridophyta spore 35%, comparable to those of the Yingcheng Group in the northern Songliao basin. The top and bottom boundary of the Yingcheng Formation in the Longshen 1 well were 2 895 m and 3 532 m respectively and the Shahezi Formation has not been cut throught.

Key words: southern Songliao basin, Yingtai depression, Longshen 1 well, deep horizon, stratification, sporopollen