Drilling speed and depth computation for downhole tools

Patent metadata

Field	Value
Publication number	US-9970285-B2
Application number	US-201514682047-A
Country	US
Kind code	B2
Filing date	Apr 8, 2015
Priority date	Jun 21, 2012
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

A method for managing a drilling operation includes generating, by a first sensor and a second sensor of a bottom hole assembly (BHA), a first time based data log and a second time based data log representing a borehole parameter along a drilling trajectory. A time shift is determined by comparing the first time based data log and the second time based data log. The time shift is processed along with an axial distance between the sensors to compute a rate of penetration.

First claim

What is claimed is:

1. A method for determining a rate of penetration of drilling of a subterranean well, the method comprising:
(a) acquiring a first data log using a first sensor in a bottom hole assembly;
(b) acquiring a second data log using a second sensor in the bottom hole assembly;
(c) causing a downhole processor to correlate the first and second data logs to compute a time shift;
(d) causing the downhole processor to process the time shift computed in (c) and an axial distance between the first and second sensors on the bottom hole assembly to compute the rate of penetration; and
(e) adjusting a drilling operation based on the rate of penetration computed in (d).

2. The method of claim 1 , further comprising:
(f) causing the downhole processor to integrate the rate of penetration to compute a downhole measured depth.

3. The method of claim 2 , further comprising:
(g) receiving a surface measured depth at the downhole processor via a downlink from a surface location; and
(h) causing the downhole processor to calibrate the downhole measured depth computed in (f) using the surface measured depth received in (g).

4. The method of claim 1 , further comprising:
(i) causing the downhole processor to process the rate of penetration computed in (d) to further compute at least one drilling parameter selected from the group consisting of build rate, turn rate, dogleg severity, and gravity toolface.

5. The method of claim 4 , further comprising:
(j) causing the downhole processor to process the rate of penetration and the at least one drilling parameter to compute a toolface and a steering ratio of a steering tool.

6. The method of claim 1 , further comprising:
(k) transmitting the rate of penetration to a surface location; and
(l) comparing the rate of penetration with a surface derived rate of penetration.

7. The method of claim 1 , wherein the first data log and the second data long are obtained simultaneously in (a) and (b) while drilling the subterranean wellbore.

8. The method of claim 1 , wherein first sensor and the second sensor comprise a navigation sensor, a formation evaluation sensor, a fluid sampling sensor, a pressure sensor, a temperature sensor, a downhole camera, or a caliper sensor.

9. The method of claim 1 , wherein the time shift is computed in (c) by maximizing a correlation factor.

10. The method of claim 1 , wherein the time shift is computed in (c) using at least one of the following mathematical equations:

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Assignees

• Schlumberger Technology Corp

Inventors

• Sugiura Junichi

Classifications

• E21B7/04

  Directional drilling · CPC title

• E21B44/02 Primary

  Automatic control of the tool feed ({E21B44/005,} E21B44/10 take precedence) · CPC title

• G05B15/02

  electric · CPC title

• E21B44/00

  Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions · CPC title

• E21B45/00 Primary

  Measuring the drilling time or rate of penetration · CPC title