3D Modeling of Barents Sea Hydrocarbon Systems

Maxim Korotaev

The geology of Barents Sea Basin is quite well investigated by geophysics and deep wells. Modelling of the burial history, hydrocarbon generation, and migration was done for the East Barents Sea region. Sedimentary cover of the Barents Sea is up to 18−19 km. Origin of the East Barents Sea Basin is proposed as Late Devonian. Structure of the sedimentary cover is known by seismic data and data of deep wells. Sedimentary cover of the Barents Sea is formed by Devonian-early Permian carbonate and terrigenous-carbonate rock and Late Permian−Mesozoic mostly terrigenous rocks. Late Permian−Lower Triassic terrigenous clinoform complex reaches 5−6 km in the centre of the depression. Modelling of the burial history, thermal history, and hydrocarbon generation history was done for the Barents Sea Basin. It was made for the 1D, 2D, and 3D cases, using the “Sedim” software package (Geological faculty of Moscow State University). Main stages of the modelling workflow are: 1) Oil system elements identification 2) Burial history modelling; 3) Thermal history modelling – including model calibration;4) Hydrocarbon generation modelling; 5). Hydrocarbon migration and accumulation modelling. There are some hydrocarbon systems in the Barents Sea region 1)Paleozoic.2) Upper Permian-Triassic. 3) Jurassic-Cretaceous. The result of burial history modelling, a model of tectonic history suggests: Late Devonian – formation of East Barents Sea basin; Carboniferous-Early-Permian – postrift subsidence and deep-water basin formation; Late Permian –Triassic – filling basin by clinoform complexes; Late Jurassic – weak extension event, deepening of basin; and Neogene-Quarternary – compression, uplift, erosion.The thermal history model was calibrated by thermal well logs and burial history results. Hydrocarbon generation history modelling was done for the main source rocks of the region – Permian, Middle and Upper Triassic, Late Jurassic. For Permian source rocks, the main phase of hydrocarbon generation was in the Triassic, for Triassic source rocks began in the Jurassic. and for Upper Jurassic source rock, in the middle of the Cretaceous. Permian and Triassic rocks are in the gas window, and Jurassic in the oil window. Modelling of hydrocarbon migration shows transportation of hydrocarbon from the deepest part of the depression to anticline structures. Location of hydrocarbon fields depends mainly upon location of the reservoir and precise structural maps. For the keeping of HC fields main factor is precise time and volume of erosion. Some estimations of erosion by different methods show 100−400 m in elevated parts of the basin.

AAPG Search and Discovery Article #90177©3P Arctic, Polar Petroleum Potential Conference & Exhibition, Stavanger, Norway, October 15-18, 2013