摘要:
Apparatus and method for transmitting data in a borehole (10) between a downhole installation including one or more tools (20) (for example downhole testing tools) and a surface installation (62), wherein the downhole installation is connected to the surface installation by means of a tubular conduit (such as a drill string or production tubing 14)). The apparatus comprises: an acoustic modem (26) associated with each tool, the modem acting to convert tool signals such as electrical tool signals into acoustic signals; and a hub (90) forming part of the downhole installation to which the tools and tubular conduit are connected and comprising an acoustic receiver (74) and an electromagnetic transmitter (80). The acoustic modems operate to generate acoustic signals in the downhole installation representative of the tool signals, the acoustic signals passing along the downhole installation to be received at the acoustic receiver of the hub, the received acoustic signals being used to operate the electromagnetic transmitter to transmit electromagnetic signals to the surface for reception at the surface installation.
摘要:
A method and system are presented for transmitting data along tubing in a borehole, comprising generating an acoustic signal using a transmitter at a first location on the tubing, and receiving the acoustic signal at a receiver at a second location on the tubing. The method and system further comprise: (i) generating the acoustic signal at the transmitter at a first frequency and bit rate; (ii) receiving the acoustic signal at the first frequency at the receiver and attempting to synchronise the receiver at the first frequency, and (iiia) if the synchronization is successful, continuing to transmit the acoustic signal so as to pass the data from the transmitter to the receiver; or (iiib) if the synchronization is unsuccessful, adjusting the frequency and/or bit rate of the signal and repeating steps (i)-(iii) on the basis of the adjusted signal.
摘要:
A method and system are presented for transmitting data along tubing in a borehole, comprising generating an acoustic signal using a transmitter at a first location on the tubing, and receiving the acoustic signal at a receiver at a second location on the tubing. The method and system further comprise: (i) generating the acoustic signal at the transmitter at a first frequency and bit rate; (ii) receiving the acoustic signal at the first frequency at the receiver and attempting to synchronize the receiver at the first frequency, and (iiia) if the synchronization is successful, continuing to transmit the acoustic signal so as to pass the data from the transmitter to the receiver; or (iiib) if the synchronization is unsuccessful, adjusting the frequency and/or bit rate of the signal and repeating steps (i)-(iii) on the basis of the adjusted signal.
摘要:
The present invention relates to a method to detect areas of acquired seismic data that contain ground roll. The method according to the invention allows the detection of ground roll cone on the basis of an estimate of the local ground roll velocity or even without any knowledge of the ground roll velocity. The method according to the invention is further more very useful for an automatic process of ground roll detection.
摘要:
A downhole electromagnetic telemetry unit for use with a tubing string (5) includes an insulated electrically conductive member (31) and a processing unit (15). The insulated electrically conductive member (31) is electrically coupled to the tubing string (5) at an upper measuring point (23) and a lower measuring point (25). The processing unit (15) is configured to process a voltage difference measured between the upper measuring point (23) and the lower measuring point (25) across the insulated electrically conductive member (31) and to derive therefrom a signal transmitted from a surface location (13).
摘要:
A downhole communication system and method is presented for communicating between a downhole location within a wellbore and a surface location. The system preferably comprises a first and second telemetry module, a downhole tool, and an interface electrically connecting the downhole tool to the first and second telemetry modules. The first telemetry module is connected to a string and positioned downhole within the wellbore, and configured to receive communication signals via acoustic propagation or low frequency electromagnetic transmission. The second telemetry module is connected to the string and positioned downhole within the wellbore, and configured to receive communication signals via fluid pressure pulse commands. The downhole tool is operatively connected to the string. And the interface is adapted to selectively relay digital communication signals between the downhole tool and at least one of the first and second telemetry modules.
摘要:
A downhole electromagnetic telemetry unit for use with a tubing string (5) includes an insulated electrically conductive member (31) and a processing unit (15). The insulated electrically conductive member (31) is electrically coupled to the tubing string (5) at an upper measuring point (23) and a lower measuring point (25). The processing unit (15) is configured to process a voltage difference measured between the upper measuring point (23) and the lower measuring point (25) across the insulated electrically conductive member (31) and to derive therefrom a signal transmitted from a surface location (13).
摘要:
An EM antenna for location on a pipe (10) surrounded by a casing (12). The antenna has a power source (21) for injecting a current across a first insulated section (25) of the pipe (10) and an electrode (22) for conducting the current from the pipe (10) to the casing (12). There is also a second insulated section (23) of the pipe arranged to operate together with the electrode (22) and first insulated section (25) for directing a path flow of the current. Such antennas are described both in relation to repeater arrangements as well as land and sea applications.
摘要:
A subsea communication system includes addressable nodes in a wellbore and addressable nodes on a floor, where the nodes in the wellbore and on the floor are able to communicate wirelessly with each other, such as through a formation.
摘要:
A data retrieval device for communicating between a downhole location within a wellbore (16) and a surface location (22) in which a downhole to surface telemetry system is installed and adapted to communicate between a first telemetry module and a second telemetry module with the second telemetry module (18) positioned downhole and connected to a string (12) positioned within the wellbore (16). The data retrieval device is provided with a housing adapted to be positioned inside the string; a communication device supported by the housing; a connection port positioned on the housing and adapted to be connected to a line; and an electronic module supported by the housing. The electronic module is in communication with the communication device and is adapted to store and use at least an identification parameter of the first telemetry module to intercept a signal transmission addressed to the first telemetry module from the second telemetry module (18) via the communication device.