Method and system for optimally calculating low-permeability gas reservoir pressure drop dynamic reserves based on pressure drop method

The embodiment of the invention provides a method and system for optimally calculating low-permeability gas reservoir pressure drop dynamic reserves based on a pressure drop method, and relates to the technical field of oil and gas field development. According to the method, gas reservoir medium-depth formation pressure measured at different time nodes before and after production is converted into apparent formation pressure, then the apparent formation pressure and corresponding accumulated gas production are drawn in a rectangular coordinate system, and the accumulated gas production increment under the unit apparent formation pressure is calculated according to data of the last two time nodes. Multiplying the current apparent formation pressure by the current residual dynamic reserves to obtain the current residual dynamic reserves, and finally adding the current accumulated gas production rate to obtain the low-permeability gas reservoir pressure drop dynamic reserves. According to the method, the pressur