The confined pyrolysis experiments of Kukersite kerogen in the presence and absence of minerals and water revealed the effects of mineral acidity and water/OC ratio on the conversion of kerogen into petroleum. The amount of bitumen and liquid hydrocarbons demonstrate that organic maturation rate increase with mineral acidity even in the presence of a large amount of water (water/OC 7-10). Organic maturation rate appeared unaffected with the addition of a small amount of water (water/OC 1.5), but it can be retarded with the addition of a large amount of water (water/OC 7-10) in confined pyrolysis experiments. The relative abundances of n-alkanes decrease whereas those of isoalkanes, cycloalkanes and light alkylbenzenes increase with both the mineral acidity and water/OC ratio. The relative abundances of naphalene, methylnaphalenes, phenanthrene and methylphenanthrenes also increase with mineral acidity but exhibit no clear variation trend with water/OC ratio. (c) 2008 Elsevier Ltd. All rights reserved.