公开(公告)号：CA2900094C

公开(公告)日：2021-06-01

申请号：CA2900094

申请日：2014-02-07

Applicant: XACT DOWNHOLE TELEMETRY INC

Inventor： MCRORY JOHN GODFREY

IPC: E21B47/14 ,  B06B1/06

Abstract: An acoustic transmitter for transmitting an acoustic signal through a downhole medium includes a voltage source; a composite load; and switching circuitry that applies voltage from the voltage source across the composite load in response to a drive signal. The composite load includes charge control circuitry, in the form of at least one inductor, connected electrically in series with a piezoelectric transducer that may be electrically modeled as a capacitor.

公开(公告)号：CA2900094A1

公开(公告)日：2014-08-14

申请号：CA2900094

申请日：2014-02-07

Applicant: XACT DOWNHOLE TELEMETRY INC

Inventor： MCRORY JOHN GODFREY

IPC: E21B47/14 ,  B06B1/06

Abstract: An acoustic transmitter for transmitting an acoustic signal through a downhole medium includes a voltage source; a composite load; and switching circuitry that applies voltage from the voltage source across the composite load in response to a drive signal. The composite load includes charge control circuitry, in the form of at least one inductor, connected electrically in series with a piezoelectric transducer that may be electrically modeled as a capacitor.

公开(公告)号：NO20181284A1

公开(公告)日：2018-10-04

申请号：NO20181284

申请日：2018-10-04

Applicant: XACT DOWNHOLE TELEMETRY INC

Inventor： MCRORY JOHN GODFREY

IPC: E21B47/16 ,  G01V1/22

Abstract: Methods, systems, and techniques for controlling voltage applied across a piezoelectric stack of a downhole acoustic transmitter. At least one of the temperature of the stack and the compressive stress applied to the stack is monitored. At least one of the temperature of the stack and the compressive stress applied to the stack is compared to a temperature threshold and a stress threshold, respectively. When the stack signal is an alternating voltage signal and when at least one of the temperature of the stack and the compressive stress applied to the stack respectively exceeds the temperature threshold and the stress threshold, the stack signal is modified such that a negative polarity portion of the stack signal has a maximum magnitude less than a magnitude of a negative polarity limit.

公开(公告)号：CA3030368A1

公开(公告)日：2018-01-18

申请号：CA3030368

申请日：2017-07-07

Applicant: XACT DOWNHOLE TELEMETRY INC

Inventor： XIAO XIAOJUN ,  WHALEN DAVE ,  VAN ZELM JOHN-PETER ,  MCRORY JOHN GODFREY

IPC: E21B47/14

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.

公开(公告)号：CA3031138A1

公开(公告)日：2018-04-19

申请号：CA3031138

申请日：2017-10-13

Applicant: XACT DOWNHOLE TELEMETRY INC

Inventor： XIAO XIAOJUN ,  VAN ZELM JOHN-PETER ,  MCRORY JOHN GODFREY

IPC: E21B47/16 ,  E21B47/01 ,  H01L41/053

Abstract: A downhole acoustic transmitter has a piezoelectric transducer, an enclosure in which the piezoelectric transducer is housed, a transducer preload means which applies a selected compressive force against the transducer such that a mechanical preload is applied to the 5 transducer, and an acoustic tuning element which has a first end coupled to the transducer preload means or the transducer, and an open second end. The acoustic tuning element is not coupled to anything but the transducer preload means or transducer, so the transducer preload means effectively has a second open end and thus can maintain the same preload compressive force on the transducer even when the transmitter is subjected to tension and 10 compressive forces during operation.

公开(公告)号：EP2954161A4

公开(公告)日：2016-09-28

申请号：EP14749094

申请日：2014-02-07

Applicant: XACT DOWNHOLE TELEMETRY INC

Inventor： MCRORY JOHN GODFREY

IPC: E21B47/14 ,  B06B1/02

CPC classification number: E21B47/16 ,  B06B1/0215 ,  B06B2201/55 ,  B06B2201/73 ,  E21B47/14

Abstract: An acoustic transmitter for transmitting an acoustic signal through a downhole medium includes a voltage source; a composite load; and switching circuitry that applies voltage from the voltage source across the composite load in response to a drive signal. The composite load includes charge control circuitry, in the form of at least one inductor, connected electrically in series with a piezoelectric transducer that may be electrically modeled as a capacitor.

Abstract translation: 用于通过井下介质传输声信号的声发射器包括电压源; 复合载荷 以及响应于驱动信号，从电压源跨复合负载施加电压的开关电路。 复合负载包括以至少一个电感器的形式的电荷控制电路，其与可被电模拟为电容器的压电换能器串联连接。