Abstract:

The oil resource, hydrocarbon accumulation period, hydrocarbon accumulation process and hydrocarbon accumulation
model for Gucheng oil field in Biyang depression were studied using the data of the seismic, geological well measurement, DST,
fluid inclusion of reservoir and analysis of petroleum geochemistry. The results show that the source rocks of the upper member
and lower member of Eh3 southeast depression provide oil and gas to respective formations, along southwest that is tectonic uplift
direction in Gucheng oil field. There are two periods of hydrocarbon accumulation. One key period is in the end of liaozhuang
group. At the end of Eh1, the source rock of the lower member of Eh3 southeast depression reached the peak of hydrocarbon
generation, and hydrocarbon migrated from southeast depression into structural nose of Gucheng oil field along deltatic sand
body, can form a certain scale of fossil oil accumulation. At the end of liaozhuang group, fossil oil accumulation suffered from
some degree of destruction due to tectonic uplift and fault activity, and that the source rock of the upper member of Eh3 southeast
depression reached the peak of hydrocarbon. Large mature hydrocarbon crossed fault along delta sand body, forming convergent
stepladder type of hydrocarbon accumulation model.

Key words: hydrocarbon accumulation period, hydrocarbon accumulation process, hydrocarbon accumulation model, Gucheng oilfield, Biyang depression