METHOD TO DETECT CASING POINT IN A WELL FROM RESISTIVITY AHEAD OF THE BIT

摘要

Methods are described using resistivity measurements obtained while drilling one or more offset wells using a drilling mud to guide drilling of one or more uncased intervals of a well to identify a casing point or points in the uncased intervals of the well. Resistivity data is gathered during drilling the offset well and prior to penetrating a region of interest of a known subterranean formation. The drill string in the uncased interval of the well progresses toward the region of interest, using resistivity data at similar depths to identify a casing point while the drill bit advances toward but does not penetrate the region. In certain embodiments resistivity may also be obtained in front of the drill bit in the uncased interval of the well and used in conjunction with the offset well resistivity data to identify casing points in the uncased intervals of the well.