Drill‐bit source salt‐proximity surveys for real‐time determination of bit position relative to the salt face

Abstract

Since the 1901 discovery of Spindletop, the first salt‐dome related oil field, thousands of wells have been drilled around intrusive salt bodies. The more easily drilled salt‐flank reservoirs have been tapped; today a well near the salt requires a more precise picture of the complex salt structure to maximize resource recovery from the reservoir and avoid drilling problems. Surface seismic data can be used to map the areal extent of a salt dome, and borehole seismic surveys have proven effective in mapping the flank of the salt and the shape of the overhang. Such conventional salt‐proximity surveys are typically conducted at the TD of the well. Although it provides information for future drilling, the conventional salt‐proximity survey does not address the real‐time drilling problem of tagging the salt with the drill bit when the objective was to remain close to the salt‐sediment interface.