Based on the analysis of the curves of mudstone compaction

it is ascer-tained that the smallest depth of hydrocarbon-expulsion of the Xingouzui Forma-tion in Jiangling and Qianjiang Sags of the Jianghan Basin is 2100m

and thatthe expulsion coordinated very well with hydrocarbon generation. We can seefrom the maps of palaeoburiel depth made by the resumption of eroded thick-ness and the compaction correction of strata that

most Xingouzui sourcerocks began its hydrocarbon expulsion after the deposition of the Jingsha For-mation

and that the effective source rock possessed the most extensive distribu-tion after the deposition of the fourth section of the Qiangjiang Formation. A series of excess-pressure profiles and maps have been drawn out based oncompaction curves. In accordance with the direction of hydrocarbon migration suggested by these maps and other geological conditions

the authors also eva-luated the exploration prospects of the research area.