US 2011/0226531 A1 · SYSTEM AND METHOD FOR MEASURING BOREHOLE CONDITIONS, IN PARTICULAR, VERIFICATION OF A FINAL BOREHOLE DIAMETER

Abstract

The present invention is a system and method for measuring borehole conditions, in particular for verification of a final diameter of a borehole. The system includes a drill string with a drill bit and a drilling mud circulation device, an underreamer attached to the drill string above the drill bit, and a tool body attached to the drill string, having a sensor for detecting downhole conditions, such as borehole diameter. The tool body is mounted above the underreamer and has a diameter smaller than the underreamer and drill bit. The sensor can be an ultrasonic transducer with adjustable signal amplitude and can be fixed in positions along the tool body. The system may also include a calibrator for sensor data, and an auxiliary tool body with another sensor between the drill bit and the underreamer. The method of the present invention is use of the system for final borehole verification.

Claims20

Dependent claims

A system for measuring borehole conditions, in particular for verification of a final diameter of a borehole, the system comprising:

a drill string having a bottom hole assembly with a drill bit at a terminal end thereof and a circulation means for drilling mud;
an underreaming means attached to said drill string above said drill bit and having a passage for flow of said drilling mud, said underreaming means having cutting edges so as to enlarge a diameter of said borehole after being drilled by said drill bit of said bottom hole assembly;
and
a tool body with a means for attachment to said drill string and a sensor means for detecting downhole conditions, said tool body being mounted above said underreaming means and having a diameter smaller than said underreaming means, said tool body being comprised of an outer shell body and an inner housing;
wherein said tool body is rotatably and axially aligned with said drill string, said flow of said drilling mud being along an outside of said outer shell body of said tool body and within the drill string through tool body.

2 more elements

A method for measuring a borehole, in particular for measuring a final diameter of a borehole, the method comprising the steps of:

drilling a pilot borehole using a drill string having a bottom hole assembly with a drill bit at a terminal end thereof and a circulation system for drilling mud, said circulation system flowing drilling mud through said drill string and to a surface location;
drilling a reamed borehole using an underreamer attached to said drill string above said drill bit and having a passage for flow of said drilling mud, said underreamer having cutting edges so as to enlarge a diameter of said pilot borehole to said reamed borehole;
and
measuring a diameter of the reamed borehole by a sensor on a tool body attached to said drill string and mounted above said underreamer.

1 more element

Dependencies are inferred from the claim text.

System and method for measuring borehole conditions, in particular, verification of a final borehole diameter

Life of this patent

System and method for measuring borehole conditions, in particular, verification of a final borehole diameter

Life of this patent

Abstract

Claims20