Remote sensing and measurement of distances along a borehole

• US 6,543,280 B2
• Filed: 07/03/2001
• Issued: 04/08/2003
• Est. Priority Date: 07/07/2000
• Status: Expired due to Fees

• Current Assignee: Inertial Response Incorporated
• Original Assignee: Inertial Response Incorporated
• Inventors: Duhon, Gerard J.
• Primary Examiner(s): Larkin, Daniel S.
• Assistant Examiner(s): WIGGINS, JOHN DAVID
• Application Number:
  US09/898,393
• Publication Number:
  US 20020032529A1
• Time in Patent Office: 644 Days
• Field of Search: 731/520.1, 731/520.2, 731/525.4, 731/524.5, 166/254.1, 166/254.2, 166/255.1, 175/40, 702/6
• US Class Current: 73/152.01
• CPC Class Codes: E21B 47/092 by detecting magnetic anomalies
• CPC Class Codes: E21B 47/26 Storing data down-hole, e.g. in a memory or on a record carrier
• CPC Class Codes: G01V 1/40 specially adapted for well-logging

Abstract

A borehole probe and related method and apparatus that enables information related to the depth of the probe to be determined and utilized by the probe to perform tasks. The probe, comparing its sense of depth and other sensed physical and temporal information to pre-defined procedural and conditional constraints, causes a physical action to be performed, or signals another device, or signals the surface. Generally, the probe uses sensed benchmarks within the borehole that have an associated depth as a depth framework. Within the distances between the benchmarks, the probe uses inertial or other distance measuring devices to measure distance from the benchmarks. With accurate and constant knowledge of its own depth, the probe can perform tasks autonomously and at the correct depth.

Claims

1. A probe for traversing a borehole having a plurality of benchmarks located therein at known depths, the probe comprising at least one pressure vessel having a depth reference point and depth determining devices associated with the vessel for enabling determination of depth data corresponding to the instantaneous depth of the depth reference point of the pressure vessel, comprising a clock, computer memory for storing depth information corresponding to the depths of the benchmarks, a first sensor for sensing the benchmarks within the borehole relative to the depth reference point of the pressure vessel and generating output data corresponding to the identity of the sensed benchmarks, a comparator for comparing the sensed benchmark identification data to the stored depth information to match the sensed benchmark identification data to corresponding benchmark depths and generate signals corresponding to the depth data of the depth reference point of the pressure vessel at the time of passage of the depth reference point of the pressure vessel, a second sensor for sensing displacement of the depth reference point of the pressure vessel relative to each benchmark and generating output data corresponding to the displacement of the depth reference point of the pressure vessel relative to the most recently sensed benchmark, and an analyzer for analyzing the depth data of the most recently sensed benchmark and the output data corresponding to the displacement of the reference point of the pressure vessel relative to the most recently sensed benchmark to yield data corresponding to the instantaneous depth of the depth reference point of the pressure vessel.

2. The probe of claim 1, wherein the benchmark is a passive electrical device which responds to qualified electromagnetic signals in close proximity by producing electromagnetic signals identifying itself uniquely by means of an alphanumeric number.

3. The probe of claim 1, wherein the benchmark comprises a ring installed concentrically to the inside of a borehole tubular, the ring residing within a channel or groove indentation in the tubular interior where a concentric antenna is placed and embedded along the circumference of the concentric ring, the concentric antenna being electrically connected to a passive microchip.

4. The probe of claim 1, wherein the second sensor comprises an inertial sensor located on the probe.

5. The probe of claim 1, wherein the second sensor comprises measuring wheels positioned on the probe so as to contact the borehole and turn in response to displacement of the probe relative to the borehole.

6. The probe of claim 1, further comprising an additional first sensor and an additional second sensor.

7. A method of determining the instantaneous depth of a probe in a borehole, where the probe has a depth reference point and depth determining devices for enabling determination of depth data corresponding to the instantaneous depth of the probe depth reference point, the method comprising the steps of using a probe sensor for sensing the presence of a downhole benchmark having a stored known depth relative to the surface, sensing the displacement of the probe relative to the benchmark relative to the time of passage to yield a stored instantaneous relative depth, using a computer memory, clock and comparator for comparing the sensed benchmark presence data to the stored known depth in order to match the sensed benchmark presence data to the stored benchmark depth and generate signals corresponding to the depth of the probe depth reference point at the time of passage of the probe depth reference point, and using an analyzer for combining the stored relative instantaneous depth and displacement of the probe with the known benchmark depth to yield the instantaneous depth of the probe relative to the surface at any given time.