The Study Of Petroleum Geochemistry Characteristics In Wendong Area Of Dong-pu Depression

Dongpu depression was a cenozoic fault basin in eastern china. The shahejie formation of lower tertiary is the major reservoirs, especially wenliu structure. The research object of This paper is the shahejie2 segment reservoir and shahejie3 segment reservoir of shahejie formation in wenliu area. Because of the complicated geological structure, fault crossing,and the strong heterogeneity of the reservior sand bodies, The oil and gas of the each section has the characteristic such as uneven distribution and the difference of geochemistry. Based on this kind of circumstance, and so complicated geological background,we are further discussion the geochemisty characteristic and distrbution of the oil,discuss reservoir-forming stages,it has important directive significance for the further development and exploration strategy.Based on the abundant basic data and achievements, combined application the theory and methods abaut petroleum-geology,oil-geochemical,sedimentology, drilling,logging and so on. through the research of tectonic feature and evolution , oil geochemical,source rock characteristic, petroleum source correlation and hydrocarbon accumulation, It is considered that there is rich in oil-gas reserve in wenliu area, oil-gas distributions are evey complex, the oil and gas mainly distribute in wendong area , the oil-gas reserve is about 70% of the all , In longitudinal direction,the main oil-layer are shahejie2 segment and shahejie3 segment. the oil-gas reserve of the shahejie1 segment,shahejie4 segment and dongying formation is relatively small,there are secondary reservoir.Biomarker analysis of the characteristics of Show that the oil and extract of oil sands have the higherγ-wax, it is show that the Super-salt sedimentary environment; Oleanane contain higher. Steranes showed that C27,C28,C29 distribution to "L" configuration and asymmetrical "V" configuration-based. Content to take advantage of C27.We found that the oil of shahejie2 segment and the oil of shahejie3 segment have the same geochemistry characteristics by using the oil-oil correlation technique, having homology.the oil of shahejie2 and shahejie3 segment may be originated from the source rock of shahejie3 segment.the contribution of source rock in shahejie1 segment is less.Make use of measurement of enclosure's homogenization temperature,burial history and thermal evolution history,we consider that the most important period of hydrocarbon's migration and accumulation of shahejie2 segment is the dongying formation sediment metaphase(30Ma~17Ma),it is a single-period reservoir forming; The reservoir of shahejie3 segment is two-period reservoir forming,the first migration and accumulation is the shahejie1 segment ~dongying formation sediment metaphase(33Ma~23Ma),the second migration and accumulation is the guantao formation~minghuazheng formation sediment metaphase(10Ma~0Ma).