Method to detect formation pore pressure from resistivity measurements ahead of the bit during drilling of a well

摘要

Methods of using resistivity ahead of a drill bit measurements obtained while drilling a subterranean well using a drilling mud. Resistivity data ahead of the bit is gathered during drilling and prior to penetrating a region of interest of a known subterranean formation using the drill bit and the drilling mud. The drill string progresses at known dip and azimuth angles toward the subterranean formation. The resistivity data is used to determine pore pressure ahead of the drill bit in the formation as a function of resistivity ahead of the drill bit in the formation while the drill bit advances toward but before the bit penetrates the formation while drilling.