Telemetry method and system for subsurface well and reservoir and logging data

Patent metadata

Field	Value
Publication number	US-9664815-B2
Application number	US-23755908-A
Country	US
Kind code	B2
Filing date	Sep 25, 2008
Priority date	Sep 25, 2008
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

A method and system for transmitting data through a transmission medium in a wellbore. A surface transceiver and a subsurface transceiver are each configured to selectively transmit over a plurality of transmission channels. The surface transceiver is adapted to initialize a channel to determine at least one parameter affecting the current maximum data rate for transmission of information through the channel using a given transmission methodology. At least one of the channels uses carrierless phase/amplitude (CAP) modulation for its transmission methodology. The surface transceiver and the subsurface transceiver adapt to cooperatively periodically test a channel by transmission of a calibration signal from the subsurface transceiver to the surface transceiver. Control circuitry compares the received calibration signal with the calibration signal, responding to the result of the comparison to adjust at least one parameter as necessary to achieve an optimum rate of data transmission through said channel.

First claim

What is claimed is:

1. A method of transmitting data from two or more sensors through a transmission medium in a wellbore, comprising:
determining a bandwidth of the transmission medium;
partitioning the bandwidth into a plurality of separate transmission channels, wherein each transmission channel is defined by an upper frequency limit and a lower frequency limit, and wherein each transmission channel extends along the length of the transmission medium;
continuously monitoring conditions in the transmission medium;
identifying when one of the channels experiences a reduction in operation to define a reduced operational channel; and
reallocating data that is being transmitted across the reduced operational channel to another one of the channels.

2. The method of claim 1 wherein determining a bandwidth of the transition medium includes:
determining the transmission characteristics of the transmission medium; and
identifying frequencies within the bandwidth that are unsuitable for transmission.

3. The method of claim 2 wherein partitioning the bandwidth into a plurality of separate transmission channels includes avoiding frequencies within the bandwidth that are identified as unsuitable for transmission.

4. The method of claim 1 , further comprising:
determining the transmission characteristics of the transmission medium;
determining, based on the transmission characteristics of the transmission medium, the suitability of each of the plurality of transmission channels to transmit data;
designating each of the plurality of transmission channels as either suitable for transmission or unsuitable for transmission based on the determined suitability;
allocating one or more of the plurality of transmission channels designated as suitable for transmission to transmit data from at least one of the two or more sensors.

5. The method of claim 4 wherein data from one of the at least two or more sensors is transmitted using a first one of the plurality of transmission channels and later, after the first one of the plurality of transmission channels is designated as unsuitable for transmission, data from the same one of the at least two or more sensors is transmitted using a second one of the plurality of transmission channels, where the second one of the plurality of transmission channels is designated as suitable for transmission.

6. The method of claim 1 wherein,
for each of the plurality of transmission channels, the upper frequency limit is greater than the lower frequency limit; and
the upper frequency limit and the lower frequency limit of each of the plurality of transmission channels does not overlap the upper frequency limit and the lower frequency limit of any other of the plurality of transmission channels.

7. The method of claim 1 wherein data from one of the at least two or more sensors is transmitted using at least two of the plurality of transmission channels, and wherein one of the channels uses carrierless phase/amplitude (CAP) modulation for transmission methodology.

8. The method of claim 1 , wherein the step of allocating one or more of the plurality of transmission channels is based on adapting to conditions of a media through which data is transmitted.

9. The method of claim 1 , wherein data from at least two of the two or more sensors is transmitted along the same channel and through a same modem.

10. The method of claim 1 , wherein the transmission medium has an end at surface in communication with a surface device, and an end downhole in communication with a downhole device so that the surface and downhole devices are in direct communication.

11. The method of claim 1 , wherein the transmission medium is selected from the group consisting of a wireline, a cable, fluid in the wellbore, earth surrounding the wellbore, fluid surrounding the wellbore, an optically translucent medium, and combinations thereof.

12. A system for transmitting data in a wellbore comprising:
a surface transceiver;
a wellbore transceiver in communication with the surface transceiver via a transmission medium; and
control circuitry that continuously monitors conditions in the transmission medium, identifies when a channel in the transmission medium experiences a reduction in operation, and automatically reallocates data that is being transmitted between the surface and subsurface to another channel.

13. The system of claim 12 , wherein the control circuitry determines a bandwidth of the transmission medium.

14. The system of claim 12 , wherein the control circuitry partitions the bandwidth into a plurality of separate transmission channels, wherein each transmission channel is defined by an upper frequency limit and a lower frequency limit.

15. A method of transmitting data from two or more sensors through a transmission medium in a wellbore, comprising:
determining a bandwidth of the transmission medium;
partitioning the bandwidth into a plurality of separate transmission channels, each transmission channel being defined by an upper frequency limit and a lower frequency limit, and each transmission channel extending along the length of the transmission medium;
packaging the data so that the data for each sensor is grouped together and packaged in one multi-channel data-block before being transmitted;
continuously monitoring conditions in the transmission medium;
identifying when one of the channels experiences a reduction in operation to define a reduced operational channel; and
dynamically reallocating data that is being transmitted across the reduced operational channel based on the changing conditions of the transmission medium and the movement of the sensors to another one of the channels.

Assignees

• Fanini Otto N
• Viswanathan Raman
• Maxit Jorge Omar
• Andrade Harold
• Baker Hughes Inc

Inventors

• Fanini Otto N
• Viswanathan Raman
• Maxit Jorge Omar
• Andrade Harold

Classifications

• E21B47/12

  Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling · CPC title

• G01V11/002 Primary

  Details, e.g. power supply systems for logging instruments, transmitting or recording data, specially adapted for well logging, also if the prospecting method is irrelevant (means for transmitting well survey signals E21B47/12; signal transmission systems in general G08C; transmission in general H04B) · CPC title

• G06F17/14

  Fourier, Walsh or analogous domain transformations {, e.g. Laplace, Hilbert, Karhunen-Loeve, transforms (for correlation function computation G06F17/156; spectrum analysers G01R23/16)} · CPC title