POOL-FORMING PATTERNS OF HYDROCARBON AND CONTROLLING FACTORS OF HYDROCARBON ENRICHMENT IN THE DONGYING AND THE HUIMIN SAGS

As two adjacent continental listric faults in the southern part of the Jiyang Depression, the Dongying and the Huimin sags have similar tectonic framework. They have similar petroleum geological characteristics, but their hydrocarbon-enrichment degree is apparently different. The major factors controlling hydrocarbon-enrichment include oil-source conditions, structural features, volcanic activities and the collocation of source rock-reservoir-caprock assemblages to structures. Among them, the collocation of source rock-reservoir-caprock assemblages to structures is the direct reason to result in the differences of major hydrocarbon bearing horizons and hydrocarbon pool types in different tectonic position. Combined with oil-source features, source rock-reservoir-caprock assemblages and conveyance system characteristics, the pool-forming patterns of hydrocarbon in the Dongying and the Huimin Sags can be classified as five kinds, that is, the self-generating and self-reserving lateral migration pool-forming pattern in swale zones, the upper generating and lower reserving vertical migration pool-forming pattern in swale areas, the lower generating and upper-reserving vertical migration pool-forming pattern in central uplift and northern steep-slope zones, the lower generating and upper-reserving composite migration pool-forming pattern in southern slope zones and the new generating and paleo-reserving composite pool-forming pattern in circumferential convex areas.