Shale oil and gas resource evaluation through 3D basin and petroleum systems modelling: a case study from the East Midlands, onshore UK

Technological advances in horizontal drilling and hydraulic fracturing have led to a re-evaluation of the UK Carboniferous sequences for shale oil and gas potential. In the Gainsborough Trough, hemipelagic mudstones known collectively as the Bowland Shale were deposited during the Pendleian Substage (Late Mississippian). In this study the interpretation of heritage 2D and recent 3D seismic data allowed the reconstruction of the tectonic evolution of the basin, which was simulated in a 3D basin and petroleum systems model. The model enabled the first prediction of generated, adsorbed, retained and expelled hydrocarbon volumes. Between 8 and 26 Bbbl of STOIIP, and between 11 and 38 tcf of GIIP have been estimated to lie within the Bowland Shale in the Gainsborough Trough. However, at the present time, there is considerable uncertainty concerning these in-place volumes, and no tests have proven the recoverability of oil and gas from the Bowland Shale in this area. Importantly, the Bowland Shale has been modelled as a single homogeneous layer, and thein situvolume numbers need to be corrected for a net to gross factor, once the criteria required for the definition for net reservoir in this formation are better understood.