Investigation On The Relationship Between Paleogene Temperature-pressure Field And Hydrocarbon Distribution In Zhanhua Sag

As one of the environmental parameters,temperature and pressure field affects each process of hydrocarbon accumulation,and restricts the hydrocarbon distribution finally. Investigation on the relationship between temperature-pressure field and hydrocarbon distribution,not only can enrich the research contents of hydrocarbon accumulation,but also can apply to guiding hydrocarbon exploration.This thesis takes Paleogene Zhanhua sag as research object,reveals the relationship between temperature-pressure field and enrichment of hydrocarbon and the type of reservoir and the physical property of oil,explores its inner mechanism.The study showed that there are two temperature and pressure systems in the vertical direction which is separated by Es2,the temperature and pressure values of the two systems both increase with increasing buried,temperature gradient and pressure coefficient present character of "heighten-decreases-heighten";And is divided into several temreture -pressure systems which are correspond with sedimentary center by fractures and uplifts laterally,the tempreture, the strata pressure and pressure coefficients reduce from the sub-sag center to the uplift or the fault zone, while the temreture gradient has contrary trend. Each layer in Zhanhua paleogene contains hydrocarbon, but the location in differenr layers is different, in Es4 and lower Es3 mainly accumulation in the center of the sag, while in the up-layer gradually concentrate in the margin and the fault zone; There are lithological oil-gas reservoirs mainly in Es4 and lower Es3 and structural hydrocarbon reservoirs like fault block hydrocarbon reservoirs in the up-layer; The density of the oil both increase from bottom to top layer totally and from the sub-sag center to the margin. The tempreture and pressure field control the rich state of hydrocarbon by controlling the direction and magnitude of migration; affects the type of the reservoirs by affecting the injection method; restricts the the physical property of oil by influencing the solubility of hydrocarbon components.