Experimental investigation of two-phase relative permeability of gas and water for tight gas carbonate under different test conditions

• Main Authors: Wan Teng, Yang Shenglai, Wang Lu, Sun Liting
• Format: Article
• Language: English
• Published: EDP Sciences 2019-01-01
• Series: Oil & Gas Science and Technology
• Online Access: https://ogst.ifpenergiesnouvelles.fr/articles/ogst/full_html/2019/01/ogst180278/ogst180278.html

Currently, tight carbonate gas reservoir has received little attention due to few discoveries of them. In this study, gas–water two-phase relative permeability was measured under two different conditions: High Temperature High Pore Pressure (HTHPP – 80 °C, 38 MPa), as well as Ambient Condition (AC), using whole core samples of tight gas carbonate. Relative permeability curves obtained at HTHPP showed two contrary curve profiles of gas relative permeability, corresponding to the distinctive micro-pore structure acquired from CT-Scanning. Then, based on Klinkenberg theory and a newly developed slip factor model for tight sandstone, slippage effect under AC is calibrated and the overestimation of gas relative permeability prove up to 41.72%–52.34% in an assumed heterogeneity. In addition, relative permeability curves obtained at HTHPP switch to higher gas saturation compared to that under AC with the rock wettability change from water-wet to less water-wet. And the wettability alteration is believed to be caused by charge change on mineral surface.