Tuning Assessment Methods for Shale Oil and Shale Gas in Germany
A preliminary initial assessment of potential shale gas resources for Germany was carried out by the Federal Institute for Geosciences and Natural Resources (BGR) in 2012. This was based on volumetric gas-in place estimation of three shale formations (Lower Carboniferous shales, Lower Jurassic Posidonia Shale, and Lower Cretaceous Wealden). Various parameters such as gas filled porosity and adsorption capacity are generally poorly known at an early stage of assessment. Hence, Monte-Carlo simulations were used to quantify uncertainties. The initial assessment shows that there are considerable shale gas resources in Germany (mean 13 Bill. m3), yet the uncertainties are considerable too (6.8 Bill.m3 – 22.6 Bill. m3). Therefore, further investigations on shale gas and shale oil resources in Germany are carried out. First of all we carry out an assessment of volumetric “oil in place”, similar to gas-in-place. The critical parameters (residual oil and water saturation) are measured by geochemical analyses of native core samples. This method is easily applicable and still viable with a relatively small data set. First results of the oil-in place assessment are presented. In this presentation we will also focus on the development of an enhanced assessment, based on modeling the petroleum generation potential of the shales. Using 1-D models and kinetic data sets, maturity modeling is carried out in order to assess the overall generated petroleum within each assessment unit. The amount of hydrocarbons expelled is compared with the results of gas- and oil- in-place estimations, respectively. First results for the Posidonia Shale show good accordance between these two methodologies.
AAPG Datapages/Search and Discovery Article #90194 © 2014 International Conference & Exhibition, Istanbul, Turkey, September 14-17, 2014