An apparatus and method for performing high transverse resolution voltage measurements in downhole logging tools utilized to determine the resistivity of an adjacent portion of a borehole wall Two current electrodes 508 and 509 are energized by an excitation source to create an oscillatory electric field in a borehole wall The voltage drop from each voltage electrode in a row of laterally spaced voltage electrodes 604 is measured relative to a shared voltage electrode 606 longitudinally spaced from the row of electrodes The differential voltage is used in combination with a measured current flow to determine a resistivity value for the borehole A second row of laterally spaced voltage electrodes 608 having electrodes laterally offset from the electrodes of the first row is included to provide high transverse resolution A common mode voltage at the shared voltage electrodes is measured and utilized to minimize the resistivity measurement error
申请公布号
WO2008143616(A1)
申请公布日期
2008.11.27
申请号
WO2007US12086
申请日期
2007.05.21
申请人
HALLIBURTON ENERGY SERVICES, INC.;SAN MARTIN, LUIS, E.;DAVIES, EVAN, L.