Location device with a gravity measuring device

• US 8,140,259 B2
• Filed: 07/29/2010
• Issued: 03/20/2012
• Est. Priority Date: 07/03/2007
• Status: Expired due to Fees

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Hall, David R., Lundgreen, David, Durrand, Christopher, Schwartz, Mark A.
• Primary Examiner(s): Trammell, James
• Assistant Examiner(s): Shafi, Muhammad
• Application Number:
  US12/846,647
• Publication Number:
  US 20100299102A1
• Time in Patent Office: 600 Days
• Field of Search: 701/1, 701/36, 701/49, 701/65, 701/66, 701/70, 701/80, 701/91, 701/93, 701/94, 701/200, 701/205, 701/206, 701/207, 701/208, 701/210, 701/212, 701/213, 701/214, 701/216, 701/217, 701/220, 701/221, 701/222, 701/226, 340/901, 340/988, 340/425.5, 340/429, 340/426.19, 340/426.22, 340/426.23, 340/426.24, 340/426.25, 73/17.5, 73/17.8, 73/541.5, 73/650.1, 73/650.5, 73/650.6, 73/650.9, 733/82.R, 733/82.G, 33/1.SC, 332/82, 332/83, 332/68, 332/69, 332/70, 332/77
• US Class Current: 701/207
• CPC Class Codes: E21B 47/022 of the borehole, e.g. using geomagnetism
• CPC Class Codes: G01C 21/02 by astronomical means G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 21/10 by using measurements of speed or acceleration G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01V 7/00 Measuring gravitational fields or waves; Gravimetric prospecting or detecting

Abstract

A location device has a gravity measurement instrument in communication with a database which has the locations relative to time of an astronomical object. The location device also has a timepiece indicating the time which may be used to determine the location of the astronomical object.

Claims

1. A location device embedded within a drill bit, the location device, comprising:

a gravity measurement instrument, said gravity measurement instrument being configured to measure a gravitation field at a location of said device and to generate a gravitation signal that is reflective of said gravitation field;

a timepiece indicating a time at said location during which said gravity measurement instrument measures said gravitation field and configured to generate a time signal reflective of said time;

a database that includes location data as a function of time for a first astronomical object relative to a second astronomical object, said database configured to be in communication with said gravity measurement instrument and said timepiece, said database receiving said time signal and said gravitation signal and configured to calculate;

a first vector direction dependent upon said gravitation signal and said time signal;

a second vector direction dependent upon said gravitation signal and said time signal; and

position data indicating said location of said device, said position data dependent upon said first vector direction, said second vector direction, said time signal, and said location data as a function of time.

2. The location device of claim 1, further comprising a second gravity measurement instrument to measure the gravitation field at a surface location and to generate a second gravitation signal reflective of said gravitation field at the surface location, the second gravity measurement device in communication with said database, the database further configured to compensate for anomalies in the gravitational field dependent upon the gravitation signal and the second gravitation signal.

3. The location device of claim 1, wherein the first vector direction is further dependent upon a location of said first astronomical object at said time and the second vector direction is further dependent upon a location of said second astronomical object at said time.

4. A method for locating a location of a drill bit comprising:

obtaining a drill bit having;

a gravity measurement instrument, said gravity measurement instrument configured to measure a gravitation field at a location of said gravity measurement instrument and to generate a gravitation signal reflective of said gravitation field;

a timepiece indicating a time at said location during which said gravity measurement instrument measures said gravitation field and configured to generate a time signal reflective of said time;

a database that includes location data as a function of time for a first astronomical object relative to a second astronomical object, said database configured to be in communication with said gravity measurement instrument and said timepiece, said database receiving said time signal and said gravitation signal and configured to calculate;

a first vector direction dependent upon said gravitation signal and said time signal;

a second vector direction dependent upon said gravitation signal and said time signal; and

position data indicating said location of said device dependent upon said first vector direction, said second vector direction, said time signal, and said location data as a function of time;

measuring said gravitation field at said location;

generating said gravitation signal;

generating said time signal;

calculating said first vector direction;

calculating said second vector direction;

calculating said position data.

5. The method of claim 4, further comprising:

obtaining a second gravity measurement instrument located at a surface location, said second gravity measurement instrument configured to measure a surface gravitation field and to generate a surface gravitation signal reflective of said surface gravitation field;

measuring said surface gravitational field at said surface location;

generating a surface gravitation signal;

detecting changes in said surface gravitation signal;

comparing said changes in said surface gravitation signal to said gravitation signal.

6. The method of claim 4, further comprising the first vector direction being dependent upon a location of said first astronomical object at said time and the second vector direction being dependent upon a location of said second astronomical object at said time.

7. A location device embedded within a drill bit, the location device, comprising:

a gravity measurement instrument, said gravity measurement instrument being configured to measure a gravitation field at a location of said device and to generate a gravitation signal that is reflective of said gravitation field;

a timepiece indicating a time at said location during which said gravity measurement instrument measures said gravitation field and configured to generate a time signal reflective of said time;

a database that includes location data as a function of time for at least a first astronomical object and a second astronomical object, said database configured to be in communication with said gravity measurement instrument and said timepiece, said database receiving said time signal and said gravitation signal and configured to calculate;

a first vector direction dependent upon said gravitation signal, said time signal, and a location of said first astronomical object at said time;

a second vector direction dependent upon said gravitation signal, said time signal, and a location of said second astronomical object at said second time; and

position data indicating said location of said device, said position data dependent upon said first vector direction, said second vector direction, said time signal, and said location data as a function of time.

8. The location device of claim 7, further comprising a second gravity measurement instrument to measure the gravitation field at a surface location and to generate a second gravitation signal reflective of said gravitation field at the surface location, the second gravity measurement device in communication with said database, the database further configured to compensate for anomalies in the gravitational field dependent upon the gravitation signal and the second gravitation signal.