Method and apparatus for downlink communication using dynamic threshold values for detecting transmitted signals

US7983113B2 · kind B2 · utility

Assignee

• Baker Hughes Holdings LLC · US

Inventors

• Sven Krueger · Trossingen, DE
• Thomas Kelch · Braunschweig, DE
• Joachim Treviranus · Winsen (Aller), DE
• Henning Doerge · Hanstedt, DE
• Marc Kurella · Braunschweig, DE

Key dates

• Filing date: Jun 29, 2007
• Grant date: Jul 19, 2011
• Expiry date: May 18, 2030

Classification

• Technology area (CPC E): Fixed Constructions
• CPC primary: E21B47/18
• WIPO field: Civil engineering
• WIPO sector: Other fields

Abstract

The present invention provides a method and system in which signals from the surface are sent by changing flow rate of the drilling fluid supplied to the drill string during drilling of a wellbore. The signals are sent based on a fixed or dynamic time period schemes so that the sent signals cross a dynamic threshold value in a known manner. A controller downhole sets the dynamic threshold and determines the number of times a parameter, such as voltage, relating to the changes in the flow rate crosses the set dynamic threshold. Based on the number of the number of crossings and/or the number of crossings and the timing of such crossings, the controller ascertains the signal sent from the surface for use downhole.