The invention relates to the technical field of methods for obtaining formation pressure through
oil drilling, in particular to a method for obtaining formation pressure based on
wellbore pressure difference and gas
logging total
hydrocarbon response characteristics, which comprises the following steps of: collecting and arranging
logging data,
logging gas logging total
hydrocarbon data,
drilling fluid density data and the like after three or more drilled reference wells in the same block are drilled; calculating the stratum pressure equivalent density of a reference well and the well
bottom pressure difference equivalent density of mudstone sections with different burial depths according to the data, drawing a well
bottom pressure difference-logging gas logging total
hydrocarbon intersection trend chart, reading corresponding well
bottom pressure difference equivalent density
delta P coordinate data according to the trend chart, and calculating the well bottom
pressure difference equivalent density
delta P coordinate data according to the well bottom
pressure difference-logging gas logging total hydrocarbon intersection trend chart. And finally calculating the stratum pressure equivalent density of the stratum mudstone section of the target well. According to the method, the drilled reference well and the positively-drilled target well which are located in the same block serve as
processing objects, the formation pressure calculation method based on logging information and the
wellbore pressure difference are combined with the gas logging total hydrocarbon
response characteristics, the formation pressure of the positively-drilled target well is accurately obtained while drilling, and the method has the advantages of timeliness and accuracy.