Use of Molecular Parameters of Source Rock Extracts to Constrain 3-D Hydrocarbon Migration Models: A Case Study from West Siberia

Goncharov, Ivan V.¹, Alexander N. Gagarin¹, Vadim Samoilenko¹, Nikolai Oblasov¹, Benoit Erout², Maria Saint-Germes² (1) Tomsk Petroleum Institute, Tomsk, Russia (2) BEICIP-FRANLAB, Rueil-Malmaison, France

3D petroleum system modeling was carried out to evaluate the processes of migration and trapping of expelled hydrocarbon from Bazhenov formation. A case study from central area of West-Siberian basin covering an area of 120x120 km2 is presented. The dynamic evolution of the basin, including compaction, pressure, temperature and HC generation was calculated through time and properties calibrated against observed well data. In addition to the parameters usually used like vitrinite reflectance and Tmax, different molecular parame­ters (MPI, DNR, Ts\Tm, TAS, 4\1-MDBT) of source-rocks have been used to calibrate the source-rocks thermal evolution history. These parameters allow to determinate more pre­cisely the heat flow lateral variations and thus the hydrocarbon kitchen’s locations. Moreover the comparison between molecular parameters of oils and extracts allows to define the direction of HC migration flows and moreover to estimate the distance of migration. Results from the study show that the local structures are filled by HC generated into various kitchens. The qualitative and quantitative evaluation of primary and secondary hydrocarbon migration and entrapment led to estimations of hydrocarbon charge volume in local trap. The results obtained were compared with resource volumes of discovered fields. This com­parison shows a good agreement between the modeled results and real HC volumes. This analysis enhanced the understanding of the mechanism of HC accumulation and provides a strategy for optimizing the exploration in studied area. It also highlights the benefit of using advanced geochemical data the calibration of petroleum system model.