Well data telemetry system
First Claim
1. A well data telemetry system for transmitting data around at least a part of a well bore, the system comprising a magnetic flux signal transmitter for propagating a magnetic flux signal around the well bore, means connected to the transmitter for modulating the magnetic flux signal in response to a data signal, and a receive array located to detect and respond to the magnetic flux signal at a position spaced from the transmitter, said receive array comprising at least two magnetometer assemblies, each of said assemblies comprising a sensor having at least one input axis, said receive array being capable of detecting alternating magnetic fields from 0.5 Hz up to at least 10 Khz.
2 Assignments
0 Petitions
Accused Products
Abstract
A well data telemetry system for transmitting data along at least a part of a well bore containing tubing of magnetically permeable material comprises a transmitting coil located to transmit a magnetic flux signal along the tubing and/or the surrounding geological formations, modulation circuitry connected to the coil for modulating the magnetic flux signal in response to a data signal, and an a.c. magnetometer located to detect and respond to the magnetic flux signal at a position spaced from the transmitting coil. By using an a.c. magnetometer instead of a conventional receiver coil to detect and respond to the magnetic flux signal, the system is capable of responding to the low levels of signal which are likely to be received in practice. Furthermore, the response of the a.c. magnetometer is independent of frequency so that the system may be used at low frequencies as well as high frequencies and demodulation of the transmitted signal can be effected without difficulty.
102 Citations
19 Claims
- 1. A well data telemetry system for transmitting data around at least a part of a well bore, the system comprising a magnetic flux signal transmitter for propagating a magnetic flux signal around the well bore, means connected to the transmitter for modulating the magnetic flux signal in response to a data signal, and a receive array located to detect and respond to the magnetic flux signal at a position spaced from the transmitter, said receive array comprising at least two magnetometer assemblies, each of said assemblies comprising a sensor having at least one input axis, said receive array being capable of detecting alternating magnetic fields from 0.5 Hz up to at least 10 Khz.
- 12. A well data telemetry system for transmitting data from downhole in a well bore to the surface, the system comprising a magnetic flux signal transmitter located downhole for propagating a magnetic flux signal around at least one of a part of the well bore and through the surrounding geological formations, means connected to said transmitter for modulating the magnetic flux signal in response to a data signal, and a receive array located at the surface to detect and process the magnetic flux signal, said receive array comprising at least two magnetometer assemblies spaced apart to improve a signal-to-noise ratio of the received magnetic flux signal, each of said assemblies comprising a sensor having at least three orthogonal input axes, said magnetometer being capable of detecting alternating magnetic fields.
Specification