Author : Oluseyi Olajide
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (133 download)
Book Synopsis The Application of Modified McKenzie Lithospheric Stretching Concept to 1D, 2D, and 3D Petroleum Systems Modelling Within the Saskatchewan Portion of the Williston Basin by : Oluseyi Olajide
Download or read book The Application of Modified McKenzie Lithospheric Stretching Concept to 1D, 2D, and 3D Petroleum Systems Modelling Within the Saskatchewan Portion of the Williston Basin written by Oluseyi Olajide and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A modified McKenzie's (1978) lithospheric stretching model, in combination with standard backstripped and decompacted tectonic subsidence analysis, has been used to model the geological evolution of Saskatchewan portion of the Williston Basin and to simulate and evaluate a number of Petroleum systems. A model of low strain rate extension (low stretch factor) accompanied by cooling of the underlying lithosphere satisfactorily explains the long-term subsidence history of an intracratonic basin (Allen and Armitage, 2012), and as a consequence, three key areas of modified McKenzie's model were implemented in this work. Firstly, to adopt Royden and Keen's, (1980) discontinuous depth-dependent extension model to layered rheological stratification characteristic of the lithosphere, to achieve a non-linear thermal gradient, and to address the risk of exaggerated stretching. Secondly, apply a proctracted stretching period of about 50 Ma, which facilitates a departure from instantaneous stretching, to produce subsidence at low stretch factors (syn-stretching subsidence), and subsequent prolonged post-stretching thermal subsidence when stretching ceases and the lithosphere thermally relaxes (Armitage and Allen 2010). Lastly, calculate a number of crustal and lithospheric mantle stretch factors at 37 locations within the sub-basin to facilitate 1-D modelling and introduce horizontal trends in thermal solutions. The range of modelled crustal stretch factors (1.01 - 1.10) and lithospheric mantle stretch factors (1.04 - 1.36) agree with published results. Calculated crustal thinning of 3.5 km agrees with the estimation of 3 to 4 km by Morel-A-L'Huissier et al. (1990) based upon seismic data and relates to the 3 km basement erosion prior to subsidence. This was also estimated from apatite fission track by Crowley et al. (1985). The establishment of data convergence at certain range of theoretical variables helps to calibrate simulated results to observed data, and facilitates the application of a number of modified McKenzie solutions to quantitatively fingerprint the basin-wide pattern of paleobathymetry, paleoerosion, and paleo heat-flow using data from 37 control wells. The derived basin-wide paleo-conditions from 37 control wells, each with a uniquely built 1-D burial history model, serve as inputs into a number of 2-D and subsequently 3-D simulations of source rock maturation, petroleum migration, and petroleum accumulation models. The resulting source rock maturation models suggest that Lower Paleozoic source rock units within southern Saskatchewan, (Upper Cambrian to Ordovician), attained maturity by the Late Paleozoic. In contrast, other Paleozoic source intervals (e.g. Bakken and Lodgepole Formations) did not reach maturity until the Late Cretaceous to Paleogene using standard kinetic parameters. However certain areas around salt solution collapse show narrower maturation gaps between the Upper and Lower Paleozoic source rocks. Hydrocarbon generation, migration and accumulation models indicate that the migration of generated hydrocarbon from source rock into the trap is a combination of lateral and vertical migration along the regional structural trends. The 1D, 2D and 3D basin models also identify (and replicate) existing oil/gas pools as well as 'micro-kitchens' of probable generation for stratigraphic units of the Mid to Late Paleozoic age. Volume calculations based on an invasion percolation model gives a total petroleum potential of 8,289.77 MMboe as against hybrid model which gives a total estimation of 8,316.39 MMboe within the modeled area.