Systems and methods of determining motion tool parameters in borehole logging

• US 6,975,112 B2
• Filed: 02/11/2003
• Issued: 12/13/2005
• Est. Priority Date: 06/14/2001
• Status: Expired due to Term

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Morys, Marian, Prammer, Manfred G., Goodman, George D.
• Primary Examiner(s): Shrivastav, Brij B.
• Application Number:
  US10/713,923
• Publication Number:
  US 20040251898A1
• Time in Patent Office: 1,036 Days
• Field of Search: 324/303, 324/300, 324/309, 324/307
• US Class Current: 324/303
• CPC Class Codes: E21B 47/00 Survey of boreholes or wells monitoring pressure or flow of drilling fluid E21B21/08
• CPC Class Codes: G01V 11/005 Devices for positioning logging sondes with respect to the borehole wall centralising devices for drilling rods or pipes E21B17/10; setting or locking tools in boreholes E21B23/00; locating objects in boreholes E21B47/09
• CPC Class Codes: G01V 3/32 operating with electron or nuclear magnetic resonance

Abstract

A system and method for calculating the lateral velocity of a rotating drilling tool within a borehole, the system comprising: a pair of accelerometers placed oppositely across the drilling tool axis of rotation and two magnetometers. The method comprises: reading tool radial acceleration signals a_r1, a_r2, and tangential acceleration signals, a_t1 and a_t3, obtained with a quadrature accelerometer detection system; reading B_x and B_y, the tool'"'"'s magnetic phase data, from two orthogonally placed magnetometers; determining the rotational phase angle of the drilling tool relative to the earth'"'"'s gravity field by first determining the tool'"'"'s magnetic phase, and the phase shift between the tool'"'"'s magnetic phase and gravity phase; and processing the foregoing data to yield a lateral tool velocity which optionally compensates for the effect of gravity on the accelerometers, or converts the lateral tool velocity from the tool reference frame to the borehole reference frame, or does both.

Claims

1. A method for processing information from a tool moving in a borehole within a geologic formation, comprising the steps of:

(a) sensing parameters of the tool motion using at least one accelerometer and at least one magnetometer attached to the tool;

(b) computing parameters of the tool motion in a borehole reference frame based on measurements from said at least one accelerometer and said at least one magnetometer by taking into account the orientation of said at least one accelerometer in relation to the gravitational field;

(c) monitoring the computed parameters and comparing the monitored parameter(s) to standard operating parameters; and

(d) generating a signal if one or more monitored parameters fall outside a predetermined range of operating values.

2. The method of claim 1, in step (a) using at least two accelerometers and at least two magnetometers.

3. The method of claim 2, wherein said at least two accelerometers measure the parameters a_r1, a_r2, a_t1, a_t2,

where a_ri is the radial acceleration component of the i-th accelerometer and a_tj is the tangential acceleration component of the j-th accelerometer.

4. The method of claim 1, wherein step (b) of computing parameters of the tool motion in a borehole reference frame is performed in real time.

5. The method of claim 1, wherein the computed motion parameters in step (b) are used to determine optimal activation times for NMR measurements.

6. The method of claim 1, wherein the computed motion parameters in step (b) are used to compensate NMR measurements for the motion of the tool.