The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 26, 1995
Filed:
Oct. 01, 1993
Paul L Sinclair, Clear Lake Shores, TX (US);
Shey-Min Su, Austin, TX (US);
Stanley C Gianzero, Austin, TX (US);
Halliburton Company, Houston, TX (US);
Abstract
An improved system for measuring dielectric properties of fluids in an oil well, utilizing the well casing as a waveguide for certain electromagnetic signals. A production logging tool in accordance with the invention includes a cylindrical mandrel sheathed by a housing. Transmitting and receiving coils are contained in annular grooves defined in the mandrel. In operation, the tool is suspended by a wireline logging cable within the casing of a producing well. The transmitting coils generate magnetic fields and azimuthal electric fields, which induce voltages in the receiving coils. These voltages are affected by the dielectric properties of fluids in the casing, and the voltages may be interpreted to determine dielectric properties such as water resistivity, dielectric permittivity, water hold-up, water cut, and water salinity. Due to specifically sized longitudinal mini-waveguides defined in annular regions about the circumference of the housing, the magnetic and azimuthal electric fields resulting from the transmitting coil may be sensed by the receiving coils, but the voltage-induced electric fields created by the transmitting coil are prevented from interfering with the receiving coils. Accuracy of the invention may be enhanced by using a second transmitting coil, by spacing the coils according to specific guidelines, by operating the transmitting coils between lower-cutoff and upper-cutoff frequencies, and by using fluid mixers.