Characteristics of organic acids in lacustrine organic-rich shale, Ordos Basin, China

Abstract

Organic acids are critical to studying the formation of secondary porosity in tight lacustrine reservoirs, Ordos Basin. The expelled fluids produced through hydrocarbon evolution in a semi-closed system under different pressure and temperature settings (16.9 MPa, 250 °C; 22.1 MPa, 300 °C; 32.5 MPa, 350 °C; 37.7 MPa, 370 °C; 42.9 MPa, 400 °C; and 52.2 MPa, 450 °C) were collected. In this study, 12 different organic acids were identified using ion chromatography, and both the concentration and species of organic acids indicate a two-step process.