Sweet Spots For Hydraulic Fracturing And Oil Or Gas Production In Underexplored Shales Using Key Performance Indicators: Example Of The Posidonia Shale Formation In The Netherlands

Abstract

Abstract While extensive data and experiences are available for hydraulic fracturing and hydrocarbon production from shales in the U.S.A., such a record is lacking in many underexplored shale basins worldwide. As limited data is usually available in these basins, analysis of shale prospectivity and identification of sweet spots for oil & gas production needs to be based on upfront geological characterization and modelling before drilling, hydraulic fracturing and gas production has commenced. In this paper, different reservoir characterization techniques and modelling approaches are combined to quantify key performance indicators that describe potential shale productivity across the formation. The performance indicators describe the potential for hydrocarbon generation, storage, and flow stimulation based on a limited number of shale properties, and are benchmarked using data from the prospective Barnett Shale Formation in the U.S.A. The approach has been applied to the underexplored Posidonia Shale Formation in the South of the Netherlands (West Netherlands Basin). Local maxima of the mean performance indicator across the formation correlate with local maxima in vitrinite reflectance and depth. Average performance for the Posidonia is lower than for the Barnett shale, mainly due to lower maturity and brittleness. Besides higher clay content and associated lower brittleness, the potential for hydrocarbon generation and storage capacity of the Posidonia are comparable to oil mature Barnett shale from noncore areas. Predictions of gas production in the Posidonia based on simulations of hydraulic fracturing and gas flow using well-based models are in rough agreement with gas production observed in noncore Barnett areas, but low brittleness may hamper succesfull hydraulic fracturing. The example shows that the approach can be applied to underexplored shales worldwide to quantify prospectivity, map out sweet spots, point to preferred drilling sites, and optimize field development planning.