Organic geochemical evaluation of the middle Devonian to late carboniferous source rocks, South East Murzuq Basin, SW Libya

Abstract EN

Ninety-four rock samples were taken from the Middle to Late Devonian Awaynat Wanin, Early Carboniferous Marar, Late Carboniferous Assedjefar formations.

The cuttings of Assedjefar Marar and Awaynat Wanin Formations collected from two wells, in the A1-163 oil field, locateed in the Murzuq Basin.

RockEval Pyrolysis, Total Organic Carbon (TOC) and molecular biomarker (via the use of chromatographymass spectrometry, GC-MS) as geochemical parameters were applied to find out the types of kerogen, depositional conditions and level of organic matter maturity for representative samples.

Such Formations are poor to excellent quantity of organic matter.

Results of TOC related with remaining generation potential (S2) and hydrogen index (HI) data showed that the organic matter attributed to Type II/III and Type III kerogen (gas and oilprone organic matter), as well connected to S1 parameter indicated indigenous hydrocarbon exist.

Ratios data of individual hydrocarbons, n-alkanes, isoprenoids and biomarkers parameters of Triterpanes and steranes indicate non-marine with marine organic matter deposited under non-marine conditions for Awaynat Wanin samples while Marar and Assedjiefar Formations deposited in nonmarine to deltaic conditions.

The maturity data from Tmax, spore colour index and biomarker related parameters based on terpanes, steranes, and low molecular-weight hydrocarbons indicate the studied rocks are ranged from immature to mature.