Abstract: System, apparatus, and method of telemetering downhole sensor information to the surface while operations are performed in an oil or gas well using coiled tubing. Data are transmitted on coiled tubing as digital signals encoded in acoustic signals. In one implementation, a stripper packer through which coiled tubing is moved into a well is operated between at least a first state and a second state; and an acoustic communication device responds to operation of the stripper packer such that when the stripper packer is in the first state, the acoustic communication device is decoupled from acoustic communication with the coiled tubing, but when the stripper packer is in the second state, the acoustic communication device is coupled for acoustic communication with the coiled tubing.

Abstract: A downhole telemetry system employing code division multiple access (CDMA) is disclosed. In one embodiment, the downhole telemetry system comprises one or more downhole transmitters and an uphole receiver. Each of the downhole transmitters transmits a corresponding uplink signal which is generated using amplitude modulation of corresponding code word signals. The code word signals are orthogonal to each other, and the transmitters may be configured to adjust the timing to assure synchronous arrival of the various uplink signals at the receiver. Each of the transmitters may be allocated a different number of code words when it is desired to allow for unequal bandwidth requirements. Such allocation is preferably dynamic. Additional modulation techniques may be employed with CDMA, including frequency division multiplexing, time division multiplexing, and frequency re-use.

Abstract: An electromagnetic borehole telemetry system providing improved signal to noise ratio. Adaptive filters use noise channels as references to remove noise from the signal channel. Directional detectors provide a signal channel with reduced noise content and improved noise channels with reduced signal content. Directional detectors may be magnetometers aligned with the magnetic field, or antennas aligned with the electric field, of signal or noise sources. Alignment may be performed by beam steering of the outputs of a three-channel detector, which may detect both signal and noise.

Abstract: A portion of at least one fiber is moved from a wellbore into a formation such that the portion is placed to conduct a signal responsive to at least one parameter in the formation. One particular implementation uses fiber optic cable with a process selected from the group consisting of a fracturing process, an acidizing process, and a conformance process.

Abstract: A portion of at least one fiber is moved into an exterior annulus of a well between a tubular structure in the well and the wall of the borehole of the well such that the portion is placed to conduct a signal responsive to at least one parameter in the exterior annulus. One particular implementation uses fiber optic cable with a cementing process whereby flowing cementing fluid pulls the portion of the cable into the exterior annulus.

Abstract: A system for obtaining video data is provided, the system comprising a video camera positioned down a bore-hole to obtain a plurality of video frames wherein the plurality of video frames comprises sequential video frames, wherein each of the sequential video frames contains information, and wherein a portion of the information of each of the sequential video frames comprises new information not found on a previous sequential video frame. The system also comprises a data extractor to extract information only from the portion comprising the new information from each sequential video frame.

Abstract: A downhole telemetry system having discrete multi-tone modulation and dynamic bandwidth allocation is disclosed herein. In one embodiment, the downhole telemetry system comprises a surface transceiver, a cable, and a downhole transceiver coupled to the surface transceiver via the cable. The downhole transceiver communicates to the surface transceiver using discrete multi-tone (DMT) modulation to transmit telemetry information over a set of frequency subchannels allocated for uplink communications. The surface transceiver may likewise communicate to the downhole transceiver using DMT modulation to transmit information over a set of frequency subchannels allocated for downlink communications. The number of uplink and downlink communications subchannels is preferably variable and preferably can be changed depending on the operating mode of the system.

Abstract: An electromagnetic borehole telemetry system providing improved signal to noise ratio. Adaptive filters use noise channels as references to remove noise from the signal channel. Directional detectors provide a signal channel with reduced noise content and improved noise channels with reduced signal content. Directional detectors may be magnetometers aligned with the magnetic field, or antennas aligned with the electric field, of signal or noise sources. Alignment may be performed by beam steering of the outputs of a three-channel detector, which may detect both signal and noise.

Abstract: The present disclosure provides several methods for selecting and transmitting information from downhole using more than one channel of communication wherein data streams transmitted up each communications channel are each independently interpretable without reference to data provided up the other of the communications channels. Preferred embodiments incorporate the use of a combination of at least two of mud-based telemetry, tubular-based telemetry, and electromagnetic telemetry to achieve improved results and take advantage of opportunities presented by the differences between the different channels of communication.

Abstract: An acoustic telemetry system for use in a borehole achieves both bi-directional and multi-hop communications without need for a wireline. Each step in the communications link comprises a processor and transceiver, which communicate with adjacent transceivers to achieve self-optimization. During operation, if communications deteriorate, each pair of transceivers can re-initiate optimization and attempt to reset parameters to achieve improved communications. Similarly, the system can also re-calibrate periodically to assure that optimal conditions are maintained.

Abstract: A reliable downhole acoustic telemetry system with increased data rate is disclosed. In one embodiment, the telemetry system includes a receiver having an envelope-detection demodulator and a multipulse-block distance detector that compares a baseband envelope signal to stored waveforms and indicates for each symbol interval the multipulse block having the waveform closest to the baseband envelope signal. The receiver may also include a timing recovery module that models the baseband envelope signal for the detected multipulse blocks and determines a distance for early-sampling and late-sampling of the baseband envelope signal. The timing recovery module then provides a sampling clock that minimizes the average difference between the early- and late-sampling distances. The telemetry system may further include a transmitter having an encoder and a modulator. The encoder converts a data signal into a sequence of multipulse blocks having a settling interval between the blocks.

Abstract: A method and related apparatus for high speed digital data conmunications from multiple distributed modems to a single central modem or a common transmission medium. In one embodiment, multiple downhole modems, with each modem associated with a geophone, transmit data to a surface modem over a single transmission medium. In a second embodiment, multiple transmission mediums are used and a plurality of downhole modems associated with geophones communicate to the surface modem over the downhole modem's respective transmission medium.

Abstract: An electromagnetic borehole telemetry system providing improved signal to noise ratio. Adaptive filters use noise channels as references to remove noise from the signal channel. Directional detectors provide a signal channel with reduced noise content and improved noise channels with reduced signal content. Directional detectors may be magnetometers aligned with the magnetic field, or antennas aligned with the electric field, of signal or noise sources. Alignment may be performed by beam steering of the outputs of a three-channel detector, which may detect both signal and noise.

Abstract: A synchronous CDMA telemetry system is provided for use in a wellbore. In one described embodiment, each data bit of digital outputs of multiple downhole data sources is multiplied by an orthogonal code unique to each data source. The resulting encoded outputs are modulated on a carrier frequency and summed on a transmission channel. The resulting signal is demodulated at a remote location and separately multiplied by each of the codes to separate out the contributions to the signal from each data source. The individual demodulated and decoded outputs are then integrated over the length of each data bit.

Abstract: A very high data rate telemetry system is provided for use in a wellbore. In a described embodiment, a telemetry system includes multiple nodes positioned in the wellbore and distributed over a substantial length of the wellbore. The nodes simultaneously communicate with a remote location at a very high combined data transmission rate. A method of communicating data in a wellbore is also provided. The method includes the steps of installing multiple modems in the wellbore, installing a remote modem at a location remote from the downhole modems, and simultaneously communicating data from each of the downhole modems to the remote location. Each downhole modem communicates with the remote modem using a unique set of frequency subchannels.

Abstract: A downhole telemetry system having discrete multi-tone modulation and dynamic bandwidth allocation is disclosed herein. In one embodiment, the downhole telemetry system comprises a surface transceiver, a cable, and a downhole transceiver coupled to the surface transceiver via the cable. The downhole transceiver communicates to the surface transceiver using discrete multi-tone (DMT) modulation to transmit telemetry information over a set of frequency subchannels allocated for uplink communications. The surface transceiver may likewise communicate to the downhole transceiver using DMT modulation to transmit information over a set of frequency subchannels allocated for downlink communications. The number of uplink and downlink communications subchannels is preferably variable and preferably can be changed depending on the operating mode of the system.

Abstract: A system is disclosed for synchronizing a clock in a well containing a drill string with a clock located near the surface of the well. The system includes devices for transmitting and receiving a pair of acoustic signals between locations associated with each clock and processing those signals. The system determines the time of arrival of each acoustic signal by analyzing the shape of a function of the acoustic signal chosen from a group of functions suitable to determine a clock offset with millisecond accuracy.

Abstract: An acoustic telemetry system is disclosed that reduces any through-drillstring drilling noise which contaminates a through-drillstring telemetry signal. Normal filtering operations are provided to remove noise outside the frequency band of interest, and reference signal filtering operations are provided to reduce the in-band noise, thereby enhancing the telemetry system's data rate and reliability. In one embodiment, the acoustic telemetry system includes a transmitter and a receiver. The transmitter induces an acoustic information signal that propagates along the tubing string. Existing noise in the tubing string contaminates the information signal. The receiver is provided with sensors for measuring the corrupted information signal and a reference signal that is indicative of the noise present in the measured information signal.

Abstract: This invention provides a method and an apparatus for fiber optic tomographic analysis and imaging of fluids. This invention includes a method for providing information on downhole fluid flowing in a hydrocarbon well, utilizing at least one downhole tomograph chamber (10). Light is introduced into the tomograph chamber (10) by an optical fiber bundle (24), and portions of the light are collected in other optical fiber bundles (32, 34). The collected portions of light are conveyed through the optical fiber bundles (32, 34) to a surface system (14), where the light is detected to produce signals proportional to the portions of light to provide information on optical properties of downhole fluid flowing in the well. This invention allows the generation of two or three dimensional images of multiple phase flow in the wellbore and allows determination of production parameters of multiple zones on an individual zone basis.

Abstract: A reliable, high data rate, downhole acoustic telemetry system is disclosed. In one embodiment, the acoustic telemetry system includes a tubing string with an acoustic transmitter and an acoustic receiver mounted on it. The acoustic transmitter transmits telemetry information by modulating an acoustic carrier frequency that propagates along the walls of the tubing string. The transmitter is preferably mounted at a selected position relative to the end of the tubing string. The selected position is preferably less than &lgr;/4 from the end or approximately n&lgr;/2 from the end, where &lgr; is the wavelength of the carrier frequency in the tubing string, and n is a positive integer. In a more preferred embodiment, n may be the lesser of 4 times the number of cycles in the modulating toneburst and 40. The receiver is preferably mounted at approximately (2n−1)&lgr;/4 relative to the end of the tubing string, where n is a positive integer.