Assessment of the Cenozoic Erosion Amount Using Monte Carlo Type-Petroleum Systems Modeling of the Hammerfest Basin, Western Barents Sea

Abstract

The Cenozoic uplift and erosion is often believed to be a major risk factor in hydrocarbon exploration in the Barents Sea causing petroleum redistribution and leakage from filled traps. Therefore, the estimation of erosion amount is an important but often underrepresented task in the basin modeling procedure. The assessment of erosion magnitudes and spatial distribution by geochemical and thermo chronological methods results in very different estimates and/or does not consider uncertainties of input data. In this study, this problem is approached by using Monte Carlo simulation techniques in secondary migration basin modeling. Thereby, amounts of early and late Cenozoic erosion episodes are described by probability distributions and the modeling results were evaluated considering their uncertainty ranges. In addition, overpressure and related leakage scenarios are considered in the petroleum basin models to study their effect on modeling results. It is shown that the early Cenozoic erosion event had a generally higher erosion magnitude than the late Cenozoic event (1.0-1.3 and 0.4-1.2 km respectively). Modeled erosion estimates are not very sensitive to overpressure modeling which is found to affect only the early Cenozoic erosion amount estimates at low degree.

Estimating uncertainties on net erosion from well‐log porosity data

“…This is significantly higher than values inferred by compaction studies in this area for the Cenozoic erosional event (1800-2400 m) (Ktenas, Henriksen, Meisingset, Nielsen, & Andreassen, 2017;Ktenas, Meisingset, Henriksen, & Nielsen, 2018). The compaction parameters estimated for the North Sea by Sclater and Christie (1980) are often the default values in basin modelling and for net erosion estimation (Iliffe, Lerche, & DeBuyl, 1992;Nyland, Jensen, Skagen, Skarpnes, & Vorren, 1992;Corcoran & Doré, 2005;Zieba, Daszinnies, Emmel, Lothe, Grover, & Lippard, 2014). Although widely used, they just represent one of the possible choices among various proposed normal compaction parameters (Gallagher, 1989;Hantschel & Kauerauf, 2009).…”

“…Assuming the values proposed by Sclater and Christie (1980), yields a mean value of net erosion of ≈3500 m with a standard deviation of 100 m (Table 3). The compaction parameters estimated for the North Sea by Sclater and Christie (1980) are often the default values in basin modelling and for net erosion estimation (Iliffe, Lerche, & DeBuyl, 1992;Nyland, Jensen, Skagen, Skarpnes, & Vorren, 1992;Corcoran & Doré, 2005;Zieba, Daszinnies, Emmel, Lothe, Grover, & Lippard, 2014). The compaction parameters estimated for the North Sea by Sclater and Christie (1980) are often the default values in basin modelling and for net erosion estimation (Iliffe, Lerche, & DeBuyl, 1992;Nyland, Jensen, Skagen, Skarpnes, & Vorren, 1992;Corcoran & Doré, 2005;Zieba, Daszinnies, Emmel, Lothe, Grover, & Lippard, 2014).…”

Estimation of net apparent erosion in the SW Barents Sea by applying velocity inversion analysis

“…1) has undergone a series of regional uplift and erosion episodes during the Mesozoic and Cenozoic, where the late Cenozoic episodes appear to be the most important. Due to the large hiatus in the rock record there are many alternative proposals for the amount, timing and magnitude of the erosion events (Vorren et al 1991;Faleide et al 1996; Dimakis et al 1998;Cavanagh et al 2006;Green & Duddy 2010;Henriksen et al 2011a;Laberg et al 2012;Duran et al 2013;Zieba et al 2014;Baig et al 2016;Zattin et al 2016;Ktenas et al 2017). This leaves a great deal of uncertainty with respect to the geological history of the southwestern Barents Sea, with consequences for hydrocarbon exploration.…”