发明名称 SYSTEM FOR MEASURING EARTH FORMATION RESISTIVITY THROUGH AN ELECTRICALLY CONDUCTIVE WELLBORE CASING
摘要 An instrument is disclosed for measuring resistivity of Earth formations from within a conductive pipe inside a wellbore drilled through the formations. The instrument includes a plurality of housings connected end to end and adapted to traverse the wellbore. At least one electrode is disposed on each housing. Each electrode is adapted to be placed in electrical contact with the inside of the pipe. The instrument includes a source of electrical current, a digital voltage measuring circuit and a switch. The switch is arranged to connect the source of electrical current between one of the electrodes and a current return at a selectable one of the top of the pipe and a location near the Earth's surface at a selected distance from the top of the pipe, and to connect selected pairs of the electrodes to the digital voltage measuring circuit. The pairs are selected to make voltage measurements corresponding to selected axial distances and selected lateral depths in the Earth formations.
申请公布号 CA2524728(C) 申请公布日期 2010.09.28
申请号 CA20052524728 申请日期 2005.10.28
申请人 KJT ENTERPRISES, INC. 发明人 STRACK, KURT M.;RUETER, HORST
分类号 G01V3/20;G01V3/24;G01V11/00 主分类号 G01V3/20
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