Method and system for determining pressure of drilling fluid column at bottom of ultra-deep well

The invention provides a method and system for determining the pressure of a drilling fluid column at the bottom of an ultra-deep well, and belongs to the field of petroleum and natural gas drilling. According to the method, firstly, the drilling fluid density under the high-temperature and high-pressure conditions is obtained through an experiment, the drilling fluid density obtained through the experiment is applied to drilling fluid column pressure calculation according to the drilling fluid column pressure superposition principle, and then the drilling fluid column pressure at the bottom of the ultra-deep well is obtained. According to the method, the actual condition that the density of the drilling fluid at different shaft depths is not uniform due to the compressibility of the high-density drilling fluid under the high-temperature and high-pressure conditions of the ultra-deep well is considered, and the high-precision drilling fluid column pressure at the bottom of the ultra-deep well is obtained acco