公开(公告)号：US20190301280A1

公开(公告)日：2019-10-03

申请号：US16316848

申请日：2017-07-07

Applicant: XACT Downhole Telemetry Inc.

Inventor： Xiaojun Xiao ,  Dave Whalen ,  John-Peter Van Zelm ,  John Godfrey McRory

IPC: E21B47/16

Abstract: A downhole acoustic transmitter has a pre-loaded piezoelectric transducer, an enclosure in which the piezoelectric transducer is housed, a preload spring that biases the transducer against a first end coupling of the enclosure, and an adjustable preload means mounted to the enclosure such that a selected compressive force is applied to the preload spring, which in turn urges the transducer against a face of the first end coupling such that a mechanical preload is applied to the transducer. The position of the adjustable preload means and the spring compliance are selected so that the level of mechanical preload applied to the transducer compensates for an expected amount of flexing of the acoustic telemetry transmitter due to varying tension and compression applied to the transmitter, thereby maintaining an effective preload on the transducer.