US 6,581,453 B1 · Method and apparatus for detecting and localizing unwanted matter internally in a pipe string

Abstract

A method and a device for detecting and localizing unwanted matter, e.g., cement deposits, internally in a drill string. A sleeve-shaped indicator body is dropped down through the drill string while the same occupies an operative position. Then, the indicator body lands either in a seat at the lower end of the drill string, or the indicator body becomes stuck within a pipe section at a higher level in the drill string. The drill string overlying the position of the indicator body may be considered free of deposits formed on the pipe section walls thereof, and these pipe sections thus may be re-used without any further examination or cleaning. If stuck at a higher level, the indicator body is subsequently localized at the surface through examination in context of disassembling the drill string. The indicator body also may comprise an indicator element that provides a detection signal or sign for its detection and localizing on the surface.

Claims18

Dependent claims

A method for detecting and localizing unwanted matter within pipe sections and drill collars included in a drill string, comprising:

dropping a tubular indicator body from a surface position down through the drill string, said indicator body having an insignificantly smaller external diameter than the bore diameter of the drill string, the indicator body landing either in a seat at the lower end of the drill string or being stopped and retained by unwanted matter within a pipe section higher up in the drill string;
and
when said drill string is subsequently disassembled, and prior to re-use in a drill string, examining individual pipe sections to localize the indicator body position, the localizing thereof indicating that its pipe section contains unwanted matter, and that overlying pipe sections are free of said unwanted matter formed on the internal walls thereof.

A device for detecting and localizing unwanted matter within pipe sections and drill collars included in a drill string, comprising:

a pipe piece which is formed with an internal seat, and which is mounted within the lower end of the drill string;
and
a tubular indicator body having a through-going bore and a lower end stop portion adapted to engage said seat within said pipe piece of the drill string, the indicator body also having an insignificantly smaller external diameter than the bore diameter of the drill string, and the indicator body being configured to be dropped into the drill string from surface and landing either in said seat at the lower end of the drill string or being stopped and retained by unwanted matter within a pipe section higher up in the drill string,
wherein the tubular indicator body comprises an indicator element which is detectable from outside a pipe section when said drill string is subsequently disassembled, the detection and localization of the indicator body within an individual pipe section indicating that the pipe section contains unwanted matter, and that overlying pipe sections are free of said unwanted matter formed on the internal walls thereof.

1 more element

Dependencies are inferred from the claim text.

Method and apparatus for detecting and localizing unwanted matter internally in a pipe string

Life of this patent

Method and apparatus for detecting and localizing unwanted matter internally in a pipe string

Life of this patent

Abstract

Claims18