Print this pagePetroleum Geochemistry of the Dnieper-Donets Basin, Ukraine
RUBLE, T. E.; J. L. CLAYTON, A. WARDEN, T. A. DAWS, G. F. ULMISHEK, B. P. KABYSHEV
The Dnieper-Donets Basin is part of a highly productive Devonian rift system which extends more than 1300 km from Belarus across the northern regions of Ukraine. The basin is filled with mainly Paleozoic rocks, including clastic and carbonate sequences and three thick salt formations. Basement and overlying rift fill dip southeastward to depths as great as 18 km and are structurally complex, with many fault blocks and salt tectonic features. In the northwestern part of the basin both oil and condensate are produced, whereas gas fields predominate in the southeast.
Limited geochemical data have previously been published for potential source rocks and oil or gas in the Dnieper-Donets Basin. In this investigation, we examined 167 rock samples and 39 oils and condensates from the Paleozoic section. Although source rocks were generally at high maturity levels across most of the basin, immature marine shales (T[max] <440 degrees C) with excellent to fair source potential (13-2% TOC; 300-200 HI) were identified from basin margin cores in both the Devonian and Carboniferous sections. Despite significant variations in thermal maturity, molecular and bulk compositional parameter such as pristane/phytane (Dev. 2.0-0.8; Carb. 7.0-1.0) and delta{13}C (Dev. -33 to -29o/oo; Carb. -29 to -23o/oo) were useful for oil-oil and oil-source rock correlation purposes. Preliminary results indicate that Devonian source rocks are responsible for low to moderate maturity oils located primarily in basin margin reservoirs, while Carboniferous source rocks have generated high maturity oils and condensates throughout the basin.