Abstract

Petroleum generation capability of the Patti Formation, Bida Basin of Nigeria were investigated by carrying out Total Organic Carbon (TOC) and Rock Eval pyrolysis analyses on outcrop samples obtained from fieldwork. Results obtained show that the Patti Formation is organically rich; having TOC values up to 2.49%. This implies that some of the studied samples are potential petroleum source rocks. Hydrogen index (HI) of the studied samples range from 17 to 93 mgHC/g TOC, with an average of 52 mgHC/g TOC. The oxygen index (OI) of the studied samples range from 29 to 406 mgCO2/g TOC, with an average of 107 mgCo2/g TOC. A cross plot of HI versus OI of the studied samples suggests the Patti Formation is gas prone, having mainly kerogen types III and IV. Thermal maturity of the studied samples varies between 348 to 4210C, suggesting that the studied samples are thermally immature. Calculated pyrolysable hydrocarbon is 13% of the TOC equivalent to HI of 130mgHC/g TOC. Positive x-intercept calculated from the cross plot of S2 versus TOC graph suggest effect of rock matrix, depicting adsorption of some of the hydrocarbons and variation of the organic matter facies.

Key words: Adsorption, Generation Potential, Pyrolysable Hydrocarbon, Total Organic Carbon, S2, Intercept, Rock-Eval Pyrolysis, Kerogen Type.