Generation of water-soluble organic acids from kerogen during hydrous pyrolysis: implications for porosity development.

Concentrations of organic acids ranging up to several thousand ppm have previously been found in oil-field waters. These acids have the potential to enhance porosity by dissolution of carbonates and aluminosilicates and are believed to be generated from kerogen in the late diagenetic-early catagenic stage of thermal maturation. Experimental hydrous pyrolysis of kerogens followed by GC-MS study of the distribution and abundance of low molecular weight water-soluble acids suggests that significant amounts of mono- and di-carboxylic acids are produced. When Kimmeridge kerogen was artificially matured in the presence of limonite at 330oC for 72 hr, total water-soluble acids accounted for approx 2% of the original kerogen.-R.A.H.