basin%R_o: A vitrinite reflectance model derived from basin and laboratory data

Abstract

The combination of vitrinite reflectance, apatite fission track and present-day borehole temperature data is very useful when performing tectonic and thermal reconstructions in sedimentary basins which, in turn, are essential for assessing risk in hydrocarbon exploration and for testing hypotheses of basin evolution. Releasing the full potential of the combined data set requires that the predictive models are accurate in themselves. Here, we calibrate a new kinetic vitrinite reflectance model 'basin %R o ' using borehole data from a number of sedimentary basins and vitrinite reflectance data from laboratory maturation experiments. The entire data set is inverted for the kinetic parameters of the reflectance model under consideration of uncertainty in the temperature histories of the calibration samples. The method is not sensitive to inconsistent calibration data, which are revealed by significant corrections to the temperature histories. The performance of the model is tested on independent well data from the East China Sea and the Nova Scotian Shelf. The widely used easy%R omodel overestimates vitrinite reflectance in the interval 0.5-1.7% R o by up to 0.35%. Delimiting of oil generating intervals by prediction of vitrinite reflectance may lead to significant underestimation of the generative potential, which may call for a revision of some petroleum systems. The overestimation by easy%R o may have fuelled the idea of pressure retardation of vitrinite reflectance evolution under sedimentary basin conditions, where pressures in fact are too low for this to be important.

Application of multi‐kinetic apatite fission track and (U‐Th)/He thermochronology to source rock thermal history: a case study from the Mackenzie Plain, NWT, Canada

“…These values are in accordance with the vitrinite reflectance measurements from Late Cretaceous samples elsewhere in the basin (Feinstein et al ., ). Whereas these values are still lower than the 0.55–0.8%Ro range commonly associated with oil and gas generation (Nielsen et al ., ), it is possible that our proposed temperature regime was sufficient to generate oil from the high sulphur kerogen in the shale. Such a phenomenon has been detailed for the Slater River Formation in the southeastern Mackenzie Plain where Tmax values are only between 418–425 °C (%Ro equiv : 0.36–0.49; Earnshaw & Grant, ).…”

“…The solid line shows the expected AH e date‐ eU trend for a 50 μm apatite of 0.75 r mr0 that experiences radiation damage accumulation starting at 150 Ma. %Ro values were calculated for each forward model using the basin%Ro model (Nielsen et al ., ).…”

Burial and thermal history of the Intra-Sudetic Basin (SW Poland) constrained by 1-D maturity modelling - implications for coalification and natural gas generation

“…The relationship between VR, temperature, and heating time can be used for thermal history reconstruction by applying chemical reaction kinetics using Arrhenius equat ions (Lopatin 1971;Sweeney & Burnham 1990;Waples et al 1992a, b;Hantschel & Kauerauf 2009). A number of kinetic models of vitrinite maturation have been proposed, as reviewed by Waples (1980), Sweeney & Burnham (1990), Morrow & Issler (1993), Burnham et al (2017) and Nielsen et al (2017).…”

Post‐orogenic thermal history and exhumation of the northern Appalachian Basin: Low‐temperature thermochronologic constraints

“…Temperature converted to depth along right side, using a geothermal gradient of 25 °C/ km. Hydrocarbon maturity window and peak oil and gas generation temperatures included (modified from: Tissot & Welte, 1978;Gleadow et al, 1983) as well as 1 and 2%R o values converted to temperature (Nielsen et al, 2015). Appalachian orogenies and geologic events (CDR -catchment drainage reorganization) occurring along the eastern USA included along the top (summarized from: Klitgord et al, 1988;Poag & Sevon, 1989;Pazzaglia & Brandon, 1996;Withjack et al, 1998;Withjack & Schlische, 2005;Ettensohn, 2008;Hatcher, 2010;Miller et al, 2013).…”

“…Generation windows for oil and gas included within the organic stage column (Tissot & Welte, 1978). %R o values based on a heating rate of 2.8 °C/Myr from 10°C (Nielsen et al, 2015), with the Easy%R o model in italics (Sweeney & Burnham, 1990) and the basin%R o model in bold (Nielsen et al, 2015). CAI values characterizes a maximum temperature range and the coloration of the conodont fossils (Epstein et al, 1977).…”