Wettability Determination of the CO_2-Reservoir Brine-Reservoir Rock System at High Pressures and High Temperature for Different salinities

摘要

An experimental method has been developed to determine the wettability, i.e., the contact angle, of a CO_2-reservoir brine-reservoir rock system at high pressures and high temperature using the axisymmetric drop shape analysis (ADSA) technique for the sessile drop case. The laboratory experiments were conducted for dynamic contact angle of CO_2-reservoir brine-reservoir rock covering three interesting salinities (0 mg/L, 14224.2 mg/L and 21460.6 mg/L) at P=6-35 MPa and T=97.5°C. For pure water system, qad (static advancing contact angel) increases from 71.69° to 107.1° as pressure of CO_2 increases from 6 MPa to 35 MPa. qad decreases from 71.48° to 42.01° for the 1# brine system and from 51.21° to 23.61° for the 2# brine system as pressure of CO_2 increases from 6 MPa to 35 MPa. qad for 2# brine system (21460.6 mg/L) is lower than that for 1# brine system (14224.2 mg/L) under the each same pressure.