Print this pageSensitivity Analysis of Multi Source-Rock Petroleum Systems by Using a Stochastic Basin Modeling Approach: From Example from the Norwegian Barents Sea
Conventionally, the Norwegian Barents Sea has been regarded as a mainly gas-prone petroleum province since the earliest drilling campaigns in the 1980s. The recent Goliat and Nucula oil discoveries in the southern Barents Sea shed a new light on the region. Both highlight the oil potential of the Barents Sea and underpin the need for revised exploration models.
Traditionally, mainly Mesozoic source-rocks of Triassic and Jurassic ages have been taken into consideration to explain the petroleum entrapments found in the Mesozoic carrier units. However, biomarker and isotope signatures of entrapped oils often suggest mixed oil sources and are not always characteristic for pure Mesozoic sources alone. Some rather point towards older, Paleozoic source contributions (Ohm et al. 2008). We aimed to investigate the sensitivity and significance of hydro-carbon contributions via faults from a Paleozoic source on a Mesozoic petroleum system in the southern Norwegian Barents Sea.
A complex 3D regional basin model has been constructed including modeling of subsidence and uplift, source-rock formation, thermal evolution, maturation of kerogen, expulsion from source rocks and secondary hydrocarbon migration. SINTEF’s in-house basin modeling tool SEMI (Sylta 2004) was employed to simulate the later three processes with Monte Carlo techniques.
Two different multi source-rock petroleum system scenarios were designed. Model scenario A consists of one carrier and two source-rock units (all of Mesozoic age) while model scenario B additionally considers petroleum input via fault leakage from a Permian source. Both scenarios were modeled in a stochastic approach in order to compare and evaluate the (a) influence magnitude on petroleum migration and entrapment pattern within the Jurassic Stø Formation carrier and (b) input parameter sensitivity within each modeled scenario. We will present quantitative uncertainty estimates on present-day trap fillings and will discuss input parameters that have largest effects on the oil and gas distributions in the carrier rock.
AAPG Search and Discover Article #90100©2009 AAPG International Conference and Exhibition 15-18 November 2009, Rio de Janeiro, Brazil