Electricity: measuring and testing – Of geophysical surface or subsurface in situ – With radiant energy or nonconductive-type transmitter
Patent
1987-04-06
1988-11-15
Strecker, Gerard R.
Electricity: measuring and testing
Of geophysical surface or subsurface in situ
With radiant energy or nonconductive-type transmitter
324341, G01V 330
Patent
active
047852470
ABSTRACT:
An apparatus and method for measuring formation parameters by transmitting and receiving electromagnetic signals by antennas disposed in recesses in a tubular housing member and including apparatus for reducing the coupling of electrical noise into the system resulting from conducting elements located adjacent the recesses and housing. More particularly, a method and apparatus employing electrostatic, but not magnetic, shielding of the low impedance antenna systems and inductive signal coupling to enhance the signal at the receiver is disclosed. This system is capable of measuring formation parameters in the presence of conducting bodies, e.g., the drill string, permitting incorporation of the apparatus in a measuring while drilling (MWD) logging system. In a particular embodiment, high frequency electromagnetic energy is used to measure formation resistivity. Small low impedance coils are arranged in the wall or around the outer circumferential surface of a steel drill collar and spaced from the surface a minimum distance to allow efficient propagation and reception. The low impedance receiver antennas are substantially electrostatically, but not magnetically, shielded and include inductive current coupling devices to further improve the signal. In a preferred embodiment, the coils are circularly configured about the collar and longitudinally spaced thereon to serve as transmitting and receiving elements which together with associated circuit components employ high frequency electromagnetic wave propagation techniques to measure formation parameters. The received signals are phase shifted and amplitude attenuated as they pass through the formation, and formation parameters are determined by detecting variations in travel time and attenuation between longitudinally spaced receivers.
REFERENCES:
patent: 2411696 (1946-11-01), Silverman et al.
patent: 2964698 (1960-12-01), Lehmberg
patent: 3124742 (1964-03-01), Schneider
patent: 3249858 (1966-05-01), Gouilloud
patent: 3305771 (1967-02-01), Arps
patent: 3408561 (1968-10-01), Redwine et al.
patent: 3551797 (1970-12-01), Gouilloud et al.
patent: 3753185 (1973-08-01), Mahan
patent: 3891916 (1975-06-01), Meador et al.
patent: 4107598 (1978-08-01), Meador et al.
patent: 4209747 (1980-06-01), Huchital
patent: 4319191 (1982-03-01), Meador et al.
patent: 4511843 (1985-04-01), Thoraval
patent: 4514693 (1985-04-01), Meador
patent: 4536714 (1985-08-01), Clark
patent: 4553097 (1985-11-01), Clark
Grubb et al., "Borehole Measurements of . . . in the 300 KHz to 25 MHz Frequency Range", Radio Science, vol. 1, No. 4, pp. 275-283, Apr. 1976.
Grayson William R.
Meador Richard A.
Thompson Larry W.
NL Industries Inc.
Strecker Gerard R.
LandOfFree
Drill stem logging with electromagnetic waves and electrostatica does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Drill stem logging with electromagnetic waves and electrostatica, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Drill stem logging with electromagnetic waves and electrostatica will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1105466