The characterization of unconventional reservoirs in the Bowland sequence using onshore 3D seismic data, Cleveland Basin, UK
Matthew Heath-Clarke, Kevin Taylor, David Harrison, Anthony Fogg, Fred Hughes, Matthew Haarhoff and Andy Mortimer
Journal name: First Break
Issue: Vol 34, No 2, February 2016 pp. 45 - 52
Info: Article, PDF ( 1.1Mb )
The Lambda-Mu-Rho (LMR) approach of characterizing reservoir intervals in seismic data is a useful tool for efficient well placement and completion. The successful exploitation of unconventional hydrocarbons in the UK could play a fundamental role in helping to satisfy the growing energy demand. To achieve this, it has been proved necessary to differentiate the more brittle from ductile rocks to maximize reservoir recovery. Economic gas production in unconventional plays requires hydraulic fracture stimulation. This study utilizes the impedance, density and the Lame parameters (Lambda, λ and Mu, μ) logs derived from the Amplitude Variation with Offset (AVO) inversion to compute the more seismically intuitive LMR logs and the elastic properties Poisson’s Ratio and Young’s Modulus. The optimal Carboniferous tight sandstone reservoir intervals at Kirby Misperton in the Cleveland Basin were successfully characterized using the LMR crossplot method. Tight gas-filled sandstones are characterized by a low λρ and a high μρ value as a result of their low incompressibility, high rigidity and intrinsic brittleness. The analysis confirmed that the Lower Bowland sequence is prospective from an unconventional perspective due to its high quartz content and therefore is likely to respond positively to hydraulic fracturing. Unconventional resources currently account for 43% of US gas production with gas consumption expected to increase between 2010 and 2030 (Rogers, 2011). Tight gas sandstones represent approximately 70% of all global unconventional gas production and reserves that are yet to be developed (Khlaifat et al., 2011). Although commercial exploration and production of unconventional gas in the UK is in its infancy, it offers significant potential for future gas production growth and will become increasingly important as the easily exploitable conventional gas reserves are exhausted (Law and Curtis, 2002). Most tight gas reservoirs are often characterized by a multi-layered reservoir system that are often hydraulically fractured to enhance recovery rates from the reservoir intervals (Meckel and Thomasson, 2008).