Device and method for measuring rock core-formation water-CO2 wettability change

The invention provides a device and method for measuring rock core-formation water-CO2 wettability change in a CO2 oil displacement process, belonging to the field of testing methods in the field of gas field exploration and development. The method comprises the following steps: putting rock core into a high-temperature high-pressure kettle, adjusting to a proper position to ensure that formation water can be accurately dripped onto the rock core, dripping the formation water onto the rock core to form liquid drops, charging CO2 to adjust the pressure to a first pressure point, measuring the contact angle of the liquid drops under the first pressure point, charging CO2 until the liquid drops on the rock core completely disappear, adjusting the pressure to a second pressure point, repeating the process above until completing the measurement of the contact angles of the liquid drops under all pressure points, and finally, obtaining the wettability change law. The invention can be utilized to continuously measure the rock core-formation water-CO2 contact angle at certain formation temperature under different CO2 pressures, and simulates the change of rock wettability of the real oil reservoir in the CO2 displacement process.