CONTROL OF STRATA SUPERFACE FORMS TO HYDROCARBON DISTRIBUTION-A CASE STUDY OF THE YANQI BASIN

Based on the study of the distribution characteristics of strata superface structures and forms, the Yanqi Basin was divided into slope areas, platform areas and nose areas three basic types. The factual structural superface characteristics of the basin were composed of the three types. Each type played a different part in the hydrocarbon pool-formation of the basin. The platform and nose areas were positive to hydrocarbon pool-formation, and the slope areas were unfavorable. Other factors such as the sufficient degree of oil sources should also be considered. The present hydrocarbon distribution of the Yanqi Basin was limited by its secondary structural belts, and several important hydrocarbon-bearing areas were all located in the structural belts adjacent to oil-generating sags. By study on the relationship between strata superface structural forms and main hydrocarbon distribution, it was considered that the hydrocarbon distribution of the Yanqi Basin had certain relations to the characteristics of strata superface structures, and the noses of the basin stretching form secondary structural belts into depressions played an important role in the accumulation and pool-formation of hydrocarbon from source areas to traps.