Brittleness evaluation method and system for composite reservoir rock

The invention relates to the technical field of reservoir rock brittleness evaluation, and discloses a brittleness evaluation method and system for composite reservoir rock, and the method comprises the steps: dividing a stress-strain curve of composite rock compression failure into three stages, and calculating the brittleness sensitivity index of each stage, the brittleness sensitivity index is an index used for describing the brittleness characteristic and sensitivity of the rock under compression loading; constructing an optimal matrix based on energy evolution according to energy accumulation and dissipation in different stages in the loading process; performing normalization processing on the matrix index, and converting the matrix after normalization processing into a fuzzy consistency matrix; and according to a fuzzy analytic hierarchy process, calculating relative contribution weights of the brittleness sensitivity indexes of the three stages to the brittleness of the composite rock. According to the