Device and method for measuring leakoff coefficient of supercritical carbon dioxide fracturing fluid

The invention belongs to the technical field of production increase of unconventional oil and gas and particularly relates to a device and a method for measuring a leakoff coefficient of a supercritical carbon dioxide fracturing fluid. The device and the method are used for determining the leakoff coefficient of the supercritical carbon dioxide fracturing fluid. The device for measuring the leakoff coefficient of the supercritical carbon dioxide fracturing fluid comprises a gas injection system, a pressure control system, an experimental model system and a measuring system, wherein the gas injection system injects methane or carbon dioxide into the experimental model system, the pressure control system provides pressure for the experimental model system and the gas injection system, the experimental model system provides a high-temperature and high-pressure stratum environment for experiments, and the measuring system measures the volumes of different gases flowing out in the experimental process. The temperature and the pressure of the device provided by the invention can be adjusted to satisfy the high-temperature and high-pressure environmental requirements on carbon dioxide in a supercritical state, so that the leakoff rule of the supercritical carbon dioxide fracturing fluid under different temperature and pressure conditions can be truly researched.