Shale Gas Potential of Germany - An Assessment Using Analogue Techniques
Ladage, Stefan¹; Gautier, Donald L.²; Berner, Ulrich¹
¹BGR, Hannover, Germany.
²USGS, Menlo Park, CA.
The German Raw Materials Agency received in 2010 a mandate of the Federal Government to evaluate the potential of unconventional oil and gas contained in tight shale horizons of Germany. The study focuses on key stratigraphic formations which have been identified in previous petroleum studies as potential hydrocarbon source rocks with a supra-regional distribution, and are concentrated in North Germany.
Dark Lower Carboniferous marine shale horizons and the Lower Jurassic so called Posidonia Shale as well as the Lower Cretaceous Wealden Formation are potential candidates for shale oil and gas assessments in Germany. The quality of the organic matter and the thermal maturity of these three targets match screening criteria which have been suggested by the USGS.
We present a volumetric gas in place assessment according to standard methods provided in the literature. Uncertainties are related to insufficient data coverage in many regions with respect to sediment thickness and regional facies changes within the target formations. Also, selective information on thermal maturities and organic carbon concentrations needed to been extrapolated. In order to quantify the uncertainties and bias effects we applied Monte Carlo simulations for the assessment.
All three target horizons show unconventional hydrocarbon potential with significant amounts of gas in place. As is well known, gas in place volumes are systematically higher than technically recoverable gas quantities. Therefore we apply a decline curve based method developed by the USGS allowing in general for more reliable assessments. We will show a preliminary assessment using this method applied to Jurassic Posidonia Shale.
AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012