Apparatus and methods of locating downhole anomalies

Patent metadata

Field	Value
Publication number	US-9360583-B2
Application number	US-200913393789-A
Country	US
Kind code	B2
Filing date	Oct 1, 2009
Priority date	Oct 1, 2009
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

Apparatus and methods are implemented to determine characteristics of geological formations in a well. One or more transmitters and receivers electrically imitate a moving antenna. The moving antenna produces a distribution of frequencies by utilizing the Doppler effect. Each anomaly in the well produces reflections with different frequency, amplitude and phase information. Location and characteristics of multiple anomalies can be identified simultaneously in a well.

First claim

What is claimed is:

1. A method comprising:
controlling transmission of signals downhole in a well by controlling sequencing of pulses from one or more transmitters;
controlling reception of return signals by controlling timing of data acquisition from one or more receivers, the return signals generated in response to the transmission of the signals, such that the controlled transmission and return signals mimic a moving antenna; and
determining a characteristic of a geological formation in the well using the Doppler effect, based on the mimicking.

2. The method of claim 1 , further comprising:
applying an inversion scheme to the controlled return signal to identify the presence of an anomaly, based on the mimicking.

3. The method of claim 1 , wherein controlling transmission comprises:
applying pulses to different transmitter antennas in an array of transmitter antennas such that the initiation of each pulse to the different transmitter antennas is conducted at different times.

4. The method of claim 1 , further comprising:
generating a drive signal to each transmitter antenna of an array of N transmitter antennas, N being a positive integer, to transmit the signals downhole in the well, each drive signal having a waveform signal and a transmission time-based weight signal correlated to an associated transmitter antenna; and
applying a reception time-based weight signal to each return signal from each receiver antenna of an array of M receiver antennas, M being a positive integer, each reception time-based weight signal correlated to an associated receiver antenna.

5. The method of claim 1 , further comprising:
exciting at most two transmitter antennas to radiate during a common time interval.

6. The method of claim 1 , further comprising:
forming a received time signal based on the return signals, after applying reception time-based weight signals to the return signals;
passing the received time signal though a time gate that selects portions of the received time signal with initial transients substantially removed;
separating at least one of the portions of the received time signal into decaying components or growing components such that one or more frequencies and/or one or more phases are output; and
identifying a different anomaly associated with each of the one or more frequencies and/or one or more phases.

7. The method of claim 6 , further comprising:
applying a frequency inversion to the one or more frequencies using a frequency map based on a transmitter antenna excitation scheme; and
identifying a location of the different anomaly by elevation and/or distance, associated with the one or more frequencies.

8. The method of claim 1 , further comprising:
determining, based on the return signals, a hydrocarbon source or a water source as an anomaly.

9. A machine-readable storage device that stores instructions, which when performed by a machine, cause the machine to perform operations, the operations comprising:
controlling transmission of signals downhole in a well by controlling sequencing of pulses from one or more transmitters;
controlling reception of return signals by controlling timing of data acquisition from one or more receivers, the return signals generated in response to the transmission of the signals, such that the controlled transmission and return signals mimic a moving antenna; and
determining a characteristic of a geological formation in the well using the Doppler effect, based on the mimicking.

10. The machine-readable storage device of claim 9 , wherein controlling the transmission of signals includes applying pulses to different transmitter antennas in an array of transmitter antennas such that the initiation of each pulse to the different transmitter antennas is conducted at different times.

11. The machine-readable storage device of claim 9 , wherein the operations comprise:
separating portions of a received time signal formed on the basis of the return signals into decaying components or growing components such that one or more frequencies and/or one or more phases are output;
applying a phase inversion to the one or more phases to identify each different anomaly associated with each of the one or more phases; and
identifying a different anomaly associated with each of the one or more frequencies and/or one or more phases.

12. An apparatus comprising:
a transmitter antenna;
a receiver antenna, the transmitter antenna and receiver antenna disposed on one or more collars attachable to a drill string; and
a system control center configured to control sequencing of pulses from the transmitter antenna and to control timing of data acquisition from the receiver antenna such that the transmitter antenna and the receiver antenna operatively mimic a moving antenna, the apparatus configured to determine a property of a geological formation surrounding a borehole, when the apparatus is used in a borehole, using Doppler effect associated with the mimicked moving antenna a Doppler effect associated with the mimicked moving antenna.

13. The apparatus of claim 12 , further comprising:
an array of N transmitter antennas, including the transmitter antenna, that are substantially uniformly spaced apart and/or wherein each antenna of the array has a common configuration selected from a group consisting of a coil, a wire, a toroid, and a button; and
an array of M receiver antennas, including the receiver antenna, wherein each antenna of the array has a common configuration selected from a group consisting of a coil, a wire, a toroid, and a button.

14. An apparatus comprising:
a transmitter antenna;
a receiver antenna, the transmitter antenna and receiver antenna disposed on one or more collars attachable to a drill string, wherein the transmitter antenna and the receiver antenna are arranged to operatively mimic a moving antenna to use a Doppler effect associated with the moving antenna; and
a transmission combining circuit coupled to a digital signal generator to generate a waveform for the transmitter antenna, the transmission combining circuit having one or more input nodes to receive N transmission time-based weight signals and one or more output nodes to output N adjusted transmission signals, each adjusted transmission signal being a product of the waveform and a different one of the associated transmission time-based weight signals.

15. The apparatus of claim 12 , wherein the apparatus includes:
a reception combining circuit associated with the receiver antenna, the reception combining circuit having one or more input nodes to receive N reception time-based weight signals and one or more output nodes to output N adjusted reception signals, each adjusted reception signal being a product of a received signal and a different one of the associated reception time-based weight signals.

16. The apparatus of claim 15 , wherein the apparatus includes:
a summer coupled to the one or more output nodes of the reception combining circuit, the summer having an output node to output a received time signal representative of the moving antenna.

17. The apparatus of claim 12 , wherein the apparatus includes:
a control unit to operatively send a waveform signal, transmission time-based weight signals, and reception time-based weight signals, and to operatively receive a received time signal associated with the moving antenna.

18. The apparatus of claim 12 , including a machine-readable storage device that stores instructions, which when performed by the apparatus, cause the apparatus to perform operations, the

Assignees

• Donderici Burkay
• Bittar Michael S
• Halliburton Energy Services Inc

Inventors

• Donderici Burkay
• Bittar Michael S

Classifications

• G01V3/30 Primary

  operating with electromagnetic waves · CPC title

• G01V1/46 Primary

  Data acquisition · CPC title

• E21B47/02208

  Fixed Constructions · mapped topic

• E21B47/16

  through the drill string or casing {, e.g. by torsional acoustic waves} · CPC title

• E21B47/0224

  using seismic or acoustic means · CPC title