Differential velocity sensor

Patent metadata

Field	Value
Publication number	US-11668188-B2
Application number	US-202117318840-A
Country	US
Kind code	B2
Filing date	May 12, 2021
Priority date	Feb 23, 2016
Publication date	Jun 6, 2023
Grant date	Jun 6, 2023

Abstract

A method, system, and apparatus for determining the location of a tool traveling down a wellbore by measuring a first borehole magnetic anomaly with respect to time at two known locations on a tool, comparing the time difference between the two measurements, then calculating the velocity of the tool based on the comparison and then further calculating the distance traveled by the tool in the wellbore based on the velocity calculation.

First claim

What is claimed is:

1. An apparatus for use downhole comprising:
a cylindrical housing, composed of a frangible material, with a first end, a second end, a centerline axis;
a first magnetic anomaly sensor located within the cylindrical housing, wherein the first magnetic anomaly sensor comprises a plurality of electromagnetic coils oriented about the centerline axis;
a second magnetic anomaly sensor located within the cylindrical housing and located a fixed axial distance from the first magnetic anomaly sensor, wherein the second magnetic anomaly sensor comprises a plurality of electromagnetic coils wrapped oriented about the centerline axis; and
a processor located within the cylindrical housing, operatively connected to the first magnetic anomaly sensor and the second magnetic anomaly sensor, wherein the processor compares the measurements of the first magnetic anomaly sensor, the second magnetic anomaly sensor, the time differential of those measurements, and with the fixed axial distance between the two sensors, calculates the instantaneous velocity of the tool.

2. The apparatus of claim 1 further comprising a plurality of processors.

3. The apparatus of claim 1 further comprising the processor having stored log data of the wellbore and comparing that to the two measurements to fine tune the velocity calculation.

4. The apparatus of claim 1 wherein the processor calculates the distance traveled by the tool based on the calculated instantaneous velocity.

5. The apparatus of claim 1 wherein the processor calculates the distance traveled by the tool by integrating the calculated velocity with respect to time.

6. The apparatus of claim 1 wherein the processor calculates the distance traveled by the tool using summation of the calculated velocity with respect to time.

7. The apparatus of claim 1 wherein the processor calculates the distance traveled by the tool by averaging the calculated velocity over a plurality of measurements and multiplying by time.

8. The apparatus of claim 1 wherein the processor calculates the distance traveled by the tool using a piecewise summation with respect to time.

Assignees

• Hunting Titan Inc

Inventors

• Mcbride Gene

Classifications

• E21B43/117

  Shaped-charge perforators (E21B43/118 takes precedence) · CPC title

• E21B47/0228

  using electromagnetic energy or detectors therefor · CPC title

• E21B47/092 Primary

  by detecting magnetic anomalies · CPC title

• E21B47/024

  of devices in the borehole (determining slope or direction of the borehole E21B47/022) · CPC title

• E21B43/114

  Perforators using direct fluid action {on the wall to be perforated}, e.g. abrasive jets · CPC title