Measurement while drilling bi-directional pulser operating in a near laminar annular flow channel

Abstract

A device, method, and system for creating a pressure pulse from drilling fluid within a drill string in a down hole drill collar for enabling measurement-while drilling. The device and system are designed such that primarily laminar flow exists in the area surrounding the pulser apparatus. The method associated with the reproducible and essentially noise-free pulses occurs when a pulser bell is manipulated in an upward and downward direction by a combination of the solenoid activation of a bi-directional poppet to redirect the fluid flow from the pressure reservoir to and from a sliding pressure chamber and associated upper and lower flow connecting channels. The pulse or non-pulse is converted into a digital signal uphole by a pressure transducer in conjunction with a decoding algorithm. It is then displayed to the driller and oilfield operators as useful directional and formation information that help the oilfield operator for uphole decision making regarding directional drilling. Additional pulsers can be added to the tool so that higher data bit rates can be accomplished. These higher data bit rates will provide for more comprehensive data collection thereby reducing drilling costs and optimizing oil field yields. The higher bit rate allows for more sensors that can send additional and improved information uphole without the use of open hole wire line logging which is impossible to accommodate while drilling horizontally.