The potential of organic rich roof shales in coal sequences: re-evaluation of Westphalian samples in well KB174, Campine Basin, Belgium VANDEWIJNGAERDE Wim*, NZEKWE Obinna, PIESSENS Kris & DUSAR Michiel Geological Survey of Belgium – Jennerstraat 13, Brussels *wvandewijngaerde@naturalsciences.be An evaluation of TOC and S2 values of roof shales in one drilling from the Campine Basin (Belgium) shows that particularly the most proximal shales show interesting properties compared to classical (marine) gas shales. Next to the palaeoenvironmental setting, key shale gas properties also seem to be influenced by the palaeogeographic setting. This is indicated by the systematically higher TOC content of the shales from the Westphalian A than B, where Westphalian A shales were deposited in a relatively more gently sloping delta plain. Introduction Shale gas is natural gas, generated and entrapped in organic-rich shales, acting both as source rock and reservoir. Along with tight gas and coal bed methane, it forms one of the non- conventional sources. Industrial-scale production of shale gas began in later part of the 20 th century. Nonetheless it is only during the last decade that shale gas has become an increasingly significant source of natural gas in the United States. Consequently the interest of exploitation has spread to other parts of the world with potential reserves. In Europe the estimated shale gas potential is considerable even though commercial production is yet to start. Some EU Member States already performed exploration drillings (UK and Poland), others considering it (Netherlands). In Belgium there is some interest, judging on the demand for information and samples from private organizations, where the focus lies on marine black shales of the Chokier Formation. Nonetheless, the real potential of these deposits to produce shale gas is poorly known compared to e.g. the unconventional natural gas in coal beds (Hildebrand, 2004; Ferket & Laenen, 2008). Internationally, attention is mainly focused on thick deposits of marine black shales when considering potential gas shales. This study will in contrast focus on the shale deposits present in coal-bearing sequences. The objective is to make a first evaluation of these sediments by re-evaluation of Rock-Eval data from roof shales from a drilling in the Campine Basin, Belgium (KB174 (GSB 047E0196, Hechtel-Hoef)). The focus will lie on the potential to produce hydrocarbons, and on the correlation between this potential and palaeoenvironmental setting (cf. Paproth et al., 1996), and the palaeogeographic context of these deposits.