Collaborative telemetry

Patent metadata

Field	Value
Publication number	US-9749717-B2
Application number	US-201615011532-A
Country	US
Kind code	B2
Filing date	Jan 30, 2016
Priority date	Jan 30, 2015
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

A method may include providing one or more telemetry transmission systems, the one or more transmission systems comprising one or more receivers and one or more transmitters. The method may also include transmitting a first synchronization sequence from the one or more telemetry transmission systems, the first synchronization sequence transmitted in a first channel, and the first synchronization sequence being at least a portion of a first telemetry signal. In addition, the method may include transmitting a second synchronization sequence the one or more telemetry transmission systems, the second synchronization sequence transmitted in a second channel, and the second synchronization sequence being at least a portion of a second telemetry signal. The first and second synchronization sequences may be transmitted simultaneously or at a predetermined time difference. The method may include receiving the first synchronization sequence at the one or more receivers, and receiving the second synchronization sequence at the one or more receivers.

First claim

The invention claimed is:

1. A method comprising:
providing one or more telemetry transmission systems, the one or more transmission systems comprising one or more receivers and one or more transmitters;
providing a controller, the controller in data connection with each of the one or more telemetry transmission systems;
transmitting a first synchronization sequence from the one or more telemetry transmission systems, the first synchronization sequence transmitted in a first channel, the first synchronization sequence being at least a portion of a first telemetry signal;
transmitting a second synchronization sequence from the one or more telemetry transmission systems, the second synchronization sequence transmitted in a second channel, the second synchronization sequence being at least a portion of a second telemetry signal, the first and second synchronization sequences transmitted simultaneously or at a predetermined time difference;
receiving the first synchronization sequence at the one or more receivers; and
receiving the second synchronization sequence at the one or more receivers.

2. The method of claim 1 , wherein the first synchronization sequence and the second synchronization sequence are transmitted via different physical channels.

3. The method of claim 2 , wherein the physical channels are selected from the group consisting of mud fluid column, electromagnetic through formation/drill-string, acoustic waves through drill-string, or wired-pipe.

4. The method of claim 1 , wherein the first synchronization sequence and the second synchronization sequence are transmitted via different frequency channels.

5. The method of claim 1 , wherein each of the one or more telemetry transmission systems includes a time synchronizer.

6. The method of claim 5 , wherein the time synchronizer is a single clock.

7. The method of claim 5 , wherein the time synchronizer is two or more clocks.

8. The method of claim 7 , wherein the two are more clocks are synchronized clocks.

9. The method of claim 7 , wherein the two are more clocks are not synchronized clocks and clock drift is estimated.

10. The method of claim 1 , wherein the controller includes a receiving system, the receiving system adapted to receive telemetry signals from the first channel and the second channel simultaneously.

11. The method of claim 1 , wherein the controller includes a channel propagation model.

12. The method of claim 11 , wherein the channel propagation model is a time delay tracking model, a physical propagation model, or a blended time delay model.

13. The method of claim 12 , wherein the channel propagation model is a time delay tracking model and wherein the method further comprises:
determining the estimated start time of the first synchronization sequence;
determining the estimate start time of the second synchronization sequence;
calculating a first measured time delay between the first synchronization sequence and the second synchronization sequence as the difference between the estimated start time of the first synchronization sequence and the second synchronization sequence;
obtaining signal lock in either the first channel or the second channel;
calculating a second measured time delay after signal lock in either the first channel or the second channel; and
blending the first measured time delay and the second measured time delay to obtain an updated time delay estimate, wherein the updated time delay estimate is an estimated time delay.

14. The method of claim of 12 , wherein the channel propagation model is a physical propagation model and wherein the method further comprises:
supplying a depth measurement device;
determining the distance from a first transmitter to a first receiver using the depth measurement device;
determining the speed of the telemetry signal; and
determining a predicted time delay by dividing the distance from the first transmitter to the first receiver by the speed of the telemetry signal, wherein the predicted time delay is an estimated time delay.

15. The method of claim 12 , wherein the channel propagation model is a blended time delay model and wherein the method further comprises:
determining a predicted time delay;
determining an updated time delay estimate;
blending the predicted time delay and the updated time delay to obtain an estimated time delay.

16. The method of claim 11 , further comprising the steps of:
determining an estimated time delay for the first synchronization sequence and the second synchronization sequence;
performing a combined synchronization operation from the first synchronization sequence and the second synchronization sequence using the estimated time delay to detect a combined synchronization sequence; and
time synchronizing at least one receiver to the combined synchronization sequence.

17. The method of claim 16 , wherein the step of performing a combined synchronization operation comprises correlating against the combination of the first synchronization sequence and the second synchronization sequence using a combined correlator.

18. The method of claim 17 , wherein the combined synchronization operation results in the calculation of a combined correlator coefficient, ρ c , wherein ρ c , is calculated using the equation:

ρ
c

⁡

(
k
)

=

∑

i
=
1

n

⁢

⁢

∑

j
=
1

m
i

⁢

⁢

(

r
i

⁡

(
j
)

-

r
l

_

)

⁢

(

s
i

⁡

(

k

Assignees

• Scient Drilling Int Inc

Inventors

• White Matthew
• Whitacre Timothy
• Gleason Brian
• Youssef Mohamed

Classifications

• H04Q9/00 Primary

  Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom · CPC title

• H04L7/0041

  Delay of data signal · CPC title

• H04L7/041

  using special codes as synchronising signal · CPC title

• E21B47/13

  by electromagnetic energy, e.g. radio frequency · CPC title

• H04L7/04

  Speed or phase control by synchronisation signals {(H04L7/0075 takes precedence)} · CPC title