Passive magnetic ranging for SAGD and relief wells via a linearized trailing window kalman filter

• US 9,422,803 B2
• Filed: 11/01/2012
• Issued: 08/23/2016
• Est. Priority Date: 11/01/2012
• Status: Active Grant

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Hanak, Francis Chad, Estes, Robert A.
• Primary Examiner(s): COSIMANO, EDWARD R
• Application Number:
  US13/666,646
• Publication Number:
  US 20140121971A1
• Time in Patent Office: 1,391 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: E21B 47/022 of the borehole, e.g. using geomagnetism
• CPC Class Codes: E21B 47/0228 using electromagnetic energy or detectors therefor
• CPC Class Codes: E21B 47/024 of devices in the borehole determining slope or direction of the borehole E21B47/022
• CPC Class Codes: E21B 47/09 Locating or determining the position of objects in boreholes or wells , e.g. the position of an extending arm; Identifying the free or blocked portions of pipes
• CPC Class Codes: E21B 47/092 by detecting magnetic anomalies
• CPC Class Codes: G01V 3/08 operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices with electromagnetic waves G01V3/12
• CPC Class Codes: G01V 3/26 operating with magnetic or electric fields produced or modified either by the surrounding earth formation or by the detecting device with electromagnetic waves G01V3/30
• CPC Class Codes: G01V 3/38 Processing data, e.g. for analysis, for interpretation, for correction
• CPC Class Codes: G05B 15/00 Systems controlled by a computer G05B13/00, G05B19/00 take precedence; automatic controllers with particular characteristics G05B11/00
• CPC Class Codes: G06F 17/40 Data acquisition and logging for input to computer G06F3/00
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

A method of drilling a well is disclosed. A first estimate is obtained of a location of the well with respect to a reference well at a selected depth. A magnetic measurement is obtained at the selected depth using a sensor. The obtained magnetic measurement is related to a residual magnetic charge distribution in the reference well. An expected value of the magnetic measurement at the selected depth is determined from the residual magnetic charge distribution. A second estimate is obtained of the location of the well using the first estimate of the location, the obtained magnetic measurement and the expected value of the magnetic measurement. A drilling parameter of the well is altered using the second estimate of the location.

Claims

1. A method of drilling a well, comprising:

obtaining a first estimate of a location of the well with respect to a reference well at a selected depth;

obtaining a magnetic measurement at the selected depth using a sensor, wherein the obtained magnetic measurement is related to a residual magnetic charge distribution in the reference well;

determining an expected value of the magnetic measurement at the selected depth from the residual magnetic charge distribution;

obtaining a second estimate of the location of the well using the first estimate of the location, the obtained magnetic measurement, the expected value of the magnetic measurement and a Kalman filter; and

altering a drilling parameter of the well using the second estimate of the location.

2. The method of claim 1, further comprising measuring the residual magnetic charge profile on a casing tubular at an uphole location and tracking the location of the casing tubular when it is disposed in the reference well to determine the residual magnetic charge distribution in the reference well.

3. The method of claim 1, wherein the obtained magnetic measurements further comprises rotationally invariant magnetic field measurements.

4. The method of claim 1, further comprising storing data related to estimating well location in an array having array locations X₀ . . . X_N corresponding to depths d₀ . . . d_N, respectively.

5. The method of claim 4, further comprising performing a trailing filter to update the estimate of well location at the second to last array location X_N−

1 using the set of measurements stored at the last array location X_N prior to discarding the measurements stored at X_N.

6. The method of claim 4, further comprising estimating the well location at the selected depth d₀ corresponding to array location X₀ using data stored at array location X_N related to previous well depth d_N.

7. The method of claim 6, further comprising iteratively determining a well location at array location X_i using data stored in the X_i+1 array location to obtain the estimation of well location at the selected depth d₀.

8. A system for drilling a well proximate a reference well, comprising:

a drill string configured to drill the well;

a sensor disposed on the drill string configured to measure a downhole magnetic field;

a processor configured to;

obtain a first estimate of a location of the well with respect to a reference well at a selected depth of the sensor,

obtain from the sensor a magnetic measurement at the selected depth related to a residual magnetic charge distribution in the reference well,

determine an expected value of the magnetic measurement at the selected depth from the residual magnetic charge distribution,

obtain a second estimate of the location of the well using the first estimate of the location, the obtained magnetic measurement, the expected value of the magnetic measurement and a Kalman filter, and

alter a drilling parameter of the well using the second estimate of the location.

9. The system of claim 8, wherein the residual magnetic charge distribution is determine from a residual magnetic charge profile on a casing tubular determined at an uphole location and a tracking location of the casing tubular in the reference well.

10. The system of claim 8, wherein the obtained magnetic measurements further comprises rotationally invariant magnetic field measurements.

11. The system of claim 8, wherein the processor is further configured to store data related to estimating well location in an array having array locations X₀ . . . X_N corresponding to depths d₀ . . . d_N, respectively.

12. The system of claim 11, wherein the processor is further configured to perform a trailing filter to update the estimate of well location at the second to last array location X_N−

1 using the set of measurements stored at the last array location X_N prior to discarding the measurements stored at X_N.

13. The system of claim 11, wherein the processor is further configured to estimate the well location at the selected depth d₀ corresponding to array location X₀ using data stored at array location X_N related to previous well depth d_N.

14. The system of claim 13, wherein the processor is further configured to iteratively determine a well location at array location X_i using data stored in the X_i+1 array location to obtain the estimation of well location at the selected depth d₀.

15. A computer readable medium having stored thereon instructions that when read by at least one processor enable the at least one processor to perform a method of drilling a well, the method comprising:

obtaining a magnetic measurement from a sensor at a selected depth, wherein the obtained magnetic measurement is related to a residual magnetic charge distribution in the reference well,

determining an expected value of the magnetic measurement at the selected depth from the residual magnetic charge distribution,

obtaining a second estimate of the location of the well using the first estimate of the location, the obtained magnetic measurement, the expected value of the magnetic measurement and a Kalman filter; and

altering a drilling parameter of the well using the second estimate of the location.

16. The computer readable medium of claim 15, wherein the method further comprises storing data related to estimating well location in an array having array locations X₀ . . . X_N corresponding to depths d₀ . . . d_N, respectively.

17. The computer readable medium of claim 16, further comprising estimating the well location at the selected depth d₀ corresponding to array location X₀ using data stored at array location X_N related to previous well depth d_N by iteratively determining a well location at array location X_i using data stored in the X_i+1 array location.

18. The computer readable medium of claim 16, further comprising performing a trailing filter to update the estimate of well location at the second to last array location X_N−

1 using the set of measurements stored at the last array location X_N prior to discarding the measurements stored at X_N.