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 …

An antenna for an electromagnetic tool having a longitudinal axis and a core. The antenna
includes a flexible dielectric substrate flexibly conformed about the core and an electrical …

This invention is directed to a downhole method and apparatus for simultaneously
determining the horizontal resistivity, vertical resistivity, and relative dip angle for anisotropic …

This invention is directed to a downhole method and apparatus for simultaneously
determining the horizontal resistivity, vertical resistivity, and relative dip angle for anisotropic …

Vided. In one embodiment, the tool comprises a Set of three skewed receiver antennas and
a transmitter antenna. The three skewed receiver antennas are oriented in equally Spaced …

6,630,830 B2 10/2003 Omeragic et al. 5,508,616 A 4, 1996 Sato et al. 6,636,045 B2*
10/2003 Tabarovsky et al......... 324,343 5,517,464 A 5, 1996 Lerner et al. 6,667,620 B2 …

57 ABSTRACT A directional induction logging tool is provided for mea surement while
drilling. This tool is preferably placed in a Side pocket of a drill collar, and it comprises …

A new logging-while-drilling (LWD) tool that incorporates directional antennae and long
measurement spacings has been developed and field tested. The directional …

2. Background Art Various well logging techniques are known in the field of hydrocarbon
exploration and production. These techniques typically use instruments or tools equipped …

Disclosed herein are electromagnetic resistivity logging systems and methods that employ
an antenna configuration having at most two transmitter or receiver antenna orientations that …