Improving spatial predictability of petroleum resources within the Central Tertiary Basin, Spitsbergen: A geochemical and petrographic study of coals from the eastern and western coalfields

摘要: Central Tertiary Basin (CTB) coals from a variety of palaeogeographic conditions within the Longyear and Verkhnij seams, were sampled to assess relationship between petroleum present, remaining generation potential coal geochemistry in order improve spatial predictability resources basin. Vitrinite reflectance (VR) values CTB have been shown be suppressed (Marshall et al., 2015b). This study attempts quantify correct for this suppression effect by applying Lo (1993) method (LoVR), which uses Hydrogen Index (HI) modify VR data, Rank(Sr) scale Suggate (2000, 2002), technique not affected suppression. In addition, oil expulsion thresholds investigated, with discussions on versus marine influence upon mires formed. A pseudo-van Krevelen diagram shows that majority plot Type II kerogen line, while remainder Types III lines, HI 151 410 mg HC/g TOC; however, maceral analysis predominates. is attributed presence abundant fluorescing (oil-prone) vitrinites. The LoVR, Tmax parameters all show maturity increases basin margins towards centre (i.e. Bassen Lunckefjellet, Breinosa Colesdalen) indicate are window. marginal samples at early mature stage window ~ 0.7% RO); meaning threshold could clearly defined. However, observed maturation trend somewhat parallels pathway New Zealand Coal Band (NZ Band) “envelope” Sykes Snowdon (2002) NZ data-set; therefore, it considered likely 9–10, 420–430 °C line rise Bitumen (BI). Some Lunckefjellet Colesdalen either reached or progressed beyond as indicated peak 11–12, LoVR 0.75–0.85% RO, 430–440 °C. BI 12.5–13.5 suggests some coals, “effective window”. Total sulphur (ST) contents range 0.46 12.05% indicating non-marine strong precursor peats, ST seam appearing record instances coastal retreat associated base level rise. Marine deposition seems significantly control distribution oil-prone seams across CTB. levels (as content) clear positive relationships because they started expelling oil. Conversely, negative commenced expulsion, probably window”. more influenced appear relatively earlier, plausible explanation why locality different stages