REAL-TIME TRAJECTORY ESTIMATION WITH MULTI-STATION ANALYSIS

• US 20170314384A1
• Filed: 09/28/2016
• Published: 11/02/2017
• Est. Priority Date: 09/28/2015
• Status: Active Grant

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: Wang, Shuoqin, Sorenson, Logan D., Nguyen, Hung, Chang, David
• Granted Patent: US 10,246,988 B2
• Time in Patent Office: Days
• CPC Class Codes: E21B 47/022 of the borehole, e.g. using geomagnetism
• CPC Class Codes: E21B 47/024 of devices in the borehole determining slope or direction of the borehole E21B47/022
• CPC Class Codes: E21B 7/04 Directional drilling
• CPC Class Codes: G01C 21/188 for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems

Abstract

Described is a system for position estimation. A set of raw sensor outputs are acquired from a sensor of a platform. The set of raw sensor outputs are stored in non-transitory memory. A set of optimized sensor measurements is generated by deducing errors in the raw sensor outputs using an unconstrained optimization algorithm. The system determines a position of the platform based on the set of optimized sensor measurements.

Claims

1. A system for position estimation, the system comprising;

one or more processors and a non-transitory computer-readable medium having executable instructions encoded thereon such that when executed, the one or more processors perform operations of;

acquiring a set of raw sensor outputs from a sensor of at least one platform and storing the set of raw sensor outputs in non-transitory memory;

generating a set of optimized sensor measurements by deducing errors in the raw sensor outputs using an unconstrained optimization algorithm; and

determining a position of the at least one platform based on the set of optimized sensor measurements.

2. The system as set forth in claim 1, wherein the at least one platform is a vehicle having an inertial navigation system therein.

3. The system as set forth in claim 1, wherein the at least one platform is a drilling well of a drilling site.

4. The system as set forth in claim 3, wherein the one or more processors further perform operations of:

determining drilling attitudes at all drilling sites using the set of optimized sensor measurements; and

determining a drilling trajectory at all drilling sites using the determined drilling attitudes.

5. The system as set forth in claim 1, wherein the unconstrained optimization algorithm is used to deduce at least one of magnetometer sensor errors, accelerometer sensor errors, and gyroscope sensor errors.

6. The system as set forth in claim 3, wherein the unconstrained optimization algorithm minimizes an objective function:

7. The system as set forth in claim 3, wherein if accelerometer sensors errors are relatively small compared with magnetometer sensor errors, then the unconstrained optimization algorithm minimizes an objective function:

8. The system as set forth in claim 3, wherein if gyroscope sensor errors are available, then the unconstrained optimization algorithm minimizes an objective function:

ƒ

_obj=Σ

_i=1^N(ER−

_i)²,

where ER is a measured earth rotation rate, is a theoretical earth rotation rate, and N is the number of times the drilling site has been surveyed.

9. The system as set forth in claim 3, wherein a drilling trajectory is determined from the set of optimized sensor measurements, and wherein the drilling trajectory is described by a set of points having coordinates on the trajectory of the curvature, wherein the coordinates of the set of points are determined according to the following:

10. A computer-implemented method for position estimation, comprising:

an act of causing one or more processors to execute instructions stored on a non-transitory memory such that upon execution, the one or more processors perform operations of;

acquiring a set of raw sensor outputs from a sensor of at least one platform and storing the set of raw sensor outputs in non-transitory memory;

generating a set of optimized sensor measurements by deducing errors in the raw sensor outputs using an unconstrained optimization algorithm; and

determining a position of the at least one platform based on the set of optimized sensor measurements.

11. The method as set forth in claim 10, wherein the at least one platform is a vehicle having an inertial navigation system therein.

12. The method as set forth in claim 10, wherein the at least one platform is a drilling well of a drilling site.

13. The method as set forth in claim 12, wherein the one or more processors further perform operations of:

determining drilling attitudes at all drilling sites using the set of optimized sensor measurements; and

determining a drilling trajectory at all drilling sites using the determined drilling attitudes.

14. The method as set forth in claim 10, wherein the unconstrained optimization algorithm is used to deduce at least one of magnetometer sensor errors, accelerometer sensor errors, and gyroscope sensor errors.

15. The method as set forth in claim 12, wherein the unconstrained optimization algorithm minimizes an objective function:

16. The method as set forth in claim 12, wherein if accelerometer sensors errors are relatively small compared with magnetometer sensor errors, then the unconstrained optimization algorithm minimizes an objective function:

17. The method as set forth in claim 12, wherein if gyroscope sensor errors are available, then the unconstrained optimization algorithm minimizes an objective function:

ƒ

_obj=Σ

_i=1^N(ER−

_i)²,

where ER is a measured earth rotation rate, is a theoretical earth rotation rate, and N is the number of times the drilling site has been surveyed.

18. The method as set forth in claim 12, wherein a drilling trajectory is determined from the set of optimized sensor measurements, and wherein the drilling trajectory is described by a set of points having coordinates on the trajectory of the curvature, wherein the coordinates of the set of points are determined according to the following:

19. A computer program product for position estimation, the computer program product comprising:

computer-readable instructions stored on a non-transitory computer-readable medium that are executable by a computer having one or more processors for causing the processor to perform operations of;

acquiring a set of raw sensor outputs from a sensor of at least one platform and storing the set of raw sensor outputs in non-transitory memory;

generating a set of optimized sensor measurements by deducing errors in the raw sensor outputs using an unconstrained optimization algorithm; and

determining a position of the at least one platform based on the set of optimized sensor measurements.

20. The computer program product as set forth in claim 19, wherein the at least one platform is a drilling well of a drilling site, and wherein the computer program product further comprises instructions for causing the one or more processors to perform operations of:

determining drilling attitudes at all drilling sites using the set of optimized sensor measurements; and

determining a drilling trajectory at all drilling sites using the determined drilling attitudes.

21. The computer program as set forth in claim 19, wherein the unconstrained optimization algorithm minimizes an objective function:

22. The computer program as set forth in claim 19, wherein if accelerometer sensors errors are relatively small compared with magnetometer sensor errors, then the unconstrained optimization algorithm minimizes an objective function:

23. The computer program as set forth in claim 19, wherein if gyroscope sensor errors are available, then the unconstrained optimization algorithm minimizes an objective function:

ƒ

_obj=Σ

_i=1^N(ER−

_i)²,

where ER is a measured earth rotation rate, is a theoretical earth rotation rate, and N is the number of times the drilling site has been surveyed.

24. The computer program as set forth in claim 19, wherein a drilling trajectory is determined from the set of optimized sensor measurements, and wherein the drilling trajectory is described by a set of points having coordinates on the trajectory of the curvature, wherein the coordinates of the set of points are determined according to the following: