Abstract: A method of signal processing includes providing at least a first pressure sensor and a second pressure sensor spaced in a drilling system and using an algorithm to separate the downwardly propagating waves from the upwardly propagating waves. In one or more examples, an algorithm may include determining a velocity of pressure signals in a wellbore, time-shifting and stacking pressure signals from at least the first pressure sensor and the second pressure sensor to determine a downwardly propagating noise signal, and subtracting the downwardly propagating noise signal from at least the signal from the first pressure sensor.

Abstract: A wireline apparatus for deep well measurements in a borehole being drilled includes a drill string having multiple drill pipe sections connected end-to-end, with at least one of the drill pipe sections being electrically conductive and isolated to provide an electrode section. A nonmagnetic drill pipe section is connected in the drill string below said electrode section, and a hydraulic motor having a rotatable drill bit carrying a drill bit instrument sub having a magnetic field sensing instrument package is connected to a lowermost end of the drill string. A wireline locatable within said drill string incorporates an electrode locatable within the drill pipe electrode section, and carries at its distal end a wireline instrument package that is locatable within the nonmagnetic drill pipe section to receive data representing magnetic field data from the magnetic field sensing instrument package.

Abstract: A system for verifying perforating gun status prior to perforating a wellbore. The system includes a perforating gun (38) having a leak sensor disposed therein that is positionable at a target location within the wellbore on a tubing string (30). A communication system (42, 44, 46, 48, 50) is integrated with the tubing string (30). The communication system (42, 44, 46, 48, 50) is operable to communicate with the leak sensor. A surface controller (40) is operable to send a first telemetry signal via the communication system (42, 44, 46, 48, 50) to interrogate the leak sensor regarding a leak status of the perforating gun (38), receive a second telemetry signal from the leak sensor via the communication system (42, 44, 46, 48, 50) including the leak status of the perforating gun (38) and determine whether to operate the perforating gun (38) based upon the leak status information.

Abstract: A wired drill pipe segment includes a tubular body having an axial bore, a box end disposed at a first end of the tubular body having a first core material disposed in the box end, a pin end disposed at a second end of the tubular body having a second core material disposed in the pin end, a first coil winding wound around at least a portion of the first core material and a second coil winding wound around at least a portion of the first core material, a third coil winding wound around at least a portion of the second core material and a fourth coil winding wound around at least a portion of the second core material, a first conductor connected to the first coil winding and the third coil winding and extending through the tubular body, and a second conductor connected to the second coil winding and the fourth coil winding and extending through the tubular body.

Abstract: A communication module for transfer of information along a drill string has at least one antenna coil, wherein the communication module is configured such that a central coil axis of the antenna coil is substantially perpendicular to a longitudinal axis of a drill pipe to which it is affixed. Signals are relayed magnetically from node to node to exchange data along any desired length of drill string. The drill string itself forms a portion of the magnetic flux path and the earth and/or surrounding media forms another substantial portion of the closed flux path. Magnetic induction is advantageous because the steel drill pipe is ferromagnetic and exhibits a magnetic permeability of a few hundred to a few thousand times that of air.

Abstract: A device for detecting the position occupied by a mobile element operatively associated therewith in relation to a reference position, comprising at least one container containing a fluid and a detector device operatively connected to said container, said detector device being configured so as to provide a signal to indicate the actual position of said mobile element as a function of at least one parameter recorded thereby and indicative of an operative condition of the fluid, or of a condition of operative interaction between the fluid and the detector device.

Abstract: A wireless communication and drill string telemetry system. The communication system is used for communicating information along a drill string between a boring tool and a boring machine. An insulator assembly provides an electrically insulated gap between the drill string communication path and a soil engaging electrode for the electrical return path. A transmitter assembly includes a data transmitter for encoding and transmitting a data signal. A signal coupler couples the data signal to the drill string and provides a controlled electrical connection between the drill string communication path and the soil engaging electrode. The signal coupler comprises a transformer and a current regulating circuit to adjust a voltage across the transformer's primary winding. A receiver assembly is disposed proximate the drilling machine and includes a toroidal pickup coil and a signal processing assembly.

Abstract: The present invention provides an electromagnetic telemetry apparatus and methods that include an insulating connector that comprises an outer metallic female member that has an inner conical longitudinal surface. In one embodiment, a tubular metallic male member is disposed in the female member, thereby crating an axial conical gap between the male and female members. A conical metallic sleeve having dimensions that substantially correspond to the axial conical gap is disposed in the axial conical gap. The outer tubular surface of the male member is coated with an insulating material, such as a ceramic material. A shoulder at one end of the male member prevents axial movement of the sleeve in one direction and a parallel key between the female member and a stabilizer member prevents rotational movement between the male and female members. The sleeve remains stationary relative to the insulated surface of the male member when the male and female members move longitudinally relative to each other.

Abstract: A coaxial transmission line for an electromagnetic wellbore telemetry system comprises an outer conductive pipe, an inner conductive pipe disposed coaxially inside an axial bore of the outer conductive pipe, a first electrical contact having a first contact face disposed at a first end of the inner conductive pipe, a second electrical contact having a second contact face disposed at a second end of the inner conductive pipe, wherein at least one of the first and second contact faces includes at least one slot, and an insulator disposed between the outer conductive pipe and the inner conductive pipe.

Abstract: A system for communicating with a downhole network integrated into a downhole drill string is disclosed in one aspect of the invention as including a data transmission coupler mounted to a downhole tool and adapted to transmit data across a tool joint. The data transmission coupler is also capable of transmitting data by emitting electromagnetic radiation. An antenna is focused at and positioned within sufficient range of the data transmission coupler to detect the electromagnetic radiation and receive the data. This data may then be transmitted to a receiver or other equipment. In certain embodiments, the antenna is located above ground level and may be mounted to a swivel, derrick, hoist system, kelly, or other structure. The antenna is ideally mounted to a structure which is out of the way of equipment and workers working on the drill string.

Abstract: A shear coupled acoustic telemetry system. An acoustic telemetry system includes a tubular string having a pressure-bearing wall and an acoustic telemetry assembly positioned external to the wall and operative to communicate an acoustic signal between the assembly and the wall. The assembly may be shear coupled to the wall. The assembly may include a pressure-bearing housing positioned external to the wall.

Abstract: A system for determining at least one of a lithology of a formation traversed by a borehole and an operational condition of a component of a drill string disposed in the borehole, the system including: a sensor for performing downhole measurements of a drilling parameter, the sensor being disposed at least one of at and in the drill string; a high speed wired pipe telemetry system for transmitting the downhole measurements in real time, a processor coupled to the telemetry system for receiving the measurements, the processor disposed external to the drill string; and a computer processing system coupled to the processor, the computer processing system comprising a model that receives the downhole measurements and surface measurements of a drilling parameter as input, the model providing as output at least one of the lithology of the formation and the operational condition of the component.

Abstract: A system and method are provided for providing electromagnetic (EM) measurement-while-drilling (MWD) telemetry capabilities using an existing mud-pulse MWD tool. An EM tool intercepts the output from the mud-pulse tool and generates an EM signal that mimics a mud-pulse pressure signal. The EM signal is intercepted at the surface by a receiver module that conditions the signal and inputs the signal into the existing pulse tool receiver. Since the EM signal mimics a mud-pulse signal, the pulse tool receiver does not require software or hardware modifications in order to process an EM telemetry mode. The EM tool can be adapted to also provide dual telemetry by incorporating a conventional pressure pulser that would normally be used with the pulse tool. A gap sub assembly for isolating the drill string is also provided that includes a pair of subs whose shoulders are separated by a non-conductive ceramic material and whose threads are separated by an insulative material, preferably a Kevlar™ cloth.

Abstract: An improved energy efficient intelligent pulser driver used for generating a mud pulse in a MWD (measurement while drilling) application. In the pulser driver, a direct current (DC) powered control circuit activates a three-phase DC brushless motor that operates a servo-valve. Opening of the servo-valve equalizes pressure in a plenum causing the operation of a main valve reducing flow area and causing a pressure spike in the mud column. Closing of the servo-valve creates a reduction in mud pressure that operates the main valve and increases the flow area causing an end to the pressure spike. The servo-valve is powered both in opening and closing operations by the motor.

Abstract: Methods of and apparatus for a downhole communication in a well. The well has a metallic structure which includes an insulated metallic, fluid carrying, control line. The method comprises the steps of applying signals to the control line at a first location and extracting the signals from the control line at a second location. There is also provided a downhole communication system for use in a well having a metallic structure. The metallic structure includes an insulated metallic, fluid carrying, control line. The system comprises means for applying signals to the control line at a first location and means for extracting the signals from the control line at a second location. The control line acts as a signal channel. Other methods and apparatus making use of control line carrying no fluid and/or the metallic shielding of cable having insulated metallic shield are also described.

Abstract: Methods and apparatus to configure drillstring communications are described. In one disclosed example, a method to configure drillstring communications involves generating a signal at a transmitter coupled to a drillstring, transmitting the generated signal via the transmitter to a receiver, sampling the transmitted signal at the receiver to generate a received signal, calculating a transmission characteristic based on a comparison of the generated signal and the received signal, and configuring at least one of the transmitter or receiver based on the transmission characteristic.

Abstract: In one aspect of the invention, a downhole power generation assembly has a downhole tool string component comprising a bore. A collar is rotatably supported within the bore and has a centralized fluid passageway and a plurality of turbine blades. The collar is connected to a power generation element such that rotation of the collar moves the power generation element and induces an electrical current.

Abstract: A measuring while drilling system typically has a metal pipework extending underground connected to an antenna. The metal pipework and the antenna are both connected to a type of downhole equipment. The antenna transmits or receives signals to/from a transceiver located on the surface, and the transceiver is connected to the metal pipeword and to a ground. The system is improved by joining a plurality of sections of wired drill pipe together to form a section where the antenna is integral with the metal pipework. One end of the section of wired drill pipe is joined to downhole equipment and another end is joined to a conventional metal pipework.

Abstract: A method for analyzing a tubing section with multiple sensors at a consistent speed to improve the analysis and grading of tubing retrieved from an oil well. An analysis speed can be pre-set or input based on the tubing being analyzed and the sensors employed. The analysis data can be retrieved and charted based on whether the data was obtained within the required analysis speed. The data can then be displayed for grading and color-coded based on the data obtained within the required ranged and that obtained outside the range. Further, the display can remove the data obtained outside the required range and link together the remaining data to improve the grading process of the tubing sections.

Abstract: A downhole communication apparatus has a signal coupler disposed in an end of a downhole tubular component. The signal coupler has a transceiver portion and a conductor portion. A data conductor integrated into the downhole tubular component is operably connected at a junction to the conductor portion of the signal coupler. A peripheral electronic device is in communication with the conductor portion of the signal coupler, either through an electrical coil wrapped around at least part of the conductor portion of the signal coupler or direct electrical contact with the conductor portion of the signal coupler.

Abstract: The specification discloses systems and methods that provide improved capability to detect and decode encoded telemetry data. More particularly, the specification discloses embodiments for detecting and decoding telemetry data by receiving a plurality of waveforms comprising encoded telemetry data. A first set of outputs is detected from the encoded telemetry data using a first set of filtering and detection parameters, and a second set of outputs is detected substantially concurrently from the encoded telemetry data using a second set of filtering and detection parameters. The sets of outputs are merged to produce decoded telemetry data.

Abstract: A wireless electromagnetic telemetry system for broadcasting signals across a bottomhole assembly disposed in a borehole drilled through a subterranean formation includes an insulated gap at a first point in the bottomhole assembly, at least one magnetic field sensor at a second point in the bottomhole assembly which measures a magnetic field, and a circuitry which modulates a voltage across the insulated gap, wherein the voltage creates an axial current along the bottomhole assembly that results in the magnetic field.

Abstract: Acoustic telemetry devices and methods that provide directional detection. In one embodiment, a disclosed acoustic telemetry device comprises at least two acoustic sensors and an electronics module.

Abstract: Disclosed herein is a sensor system having a sensor and at least one communication line operable with the sensor. The transmission medium is configured to convey data transmitted by the sensor to a remote location. The sensor transmits data on the communication line a plurality of times by at least two methods of transmission or modulation. Further disclosed herein is a method based on the foregoing. Further disclosed is a method of communicating by modifying a voltage amplitude of a signal and receiving the communication signal by employing a variable threshold detection circuit in the downhole device. Further disclosed is a system for communicating data between a downhole device and a remote location including a remote device for generating a communication signal, the remote device configured to modify a voltage amplitude of said communication signal.

Abstract: Apparatus and methods for terminating and anchoring fiber optic connections are disclosed. One apparatus includes a sealed body enclosing a passage for one or more optical fibers terminating in connections proximate a first end of the sealed body, the sealed body having a diameter less than an internal diameter of an oilfield tubular, the sealed body having a second end adapted to sealingly engage and anchor an end of a fiber optic carrier conduit, the second end connecting the sealed body to the fiber optic carrier conduit.

Abstract: A wireless data communication system for a down hole environment. The system includes a housing containing a sensor, positioned within a tubular, for collecting information and processing the information, a modulator for modulating the information from the sensor into an analog signal, and a sensor antenna electrically connected to the first modulator for generating a modulated electromagnetic wave. The system further includes a probe housing, concentrically disposed within the tubular, comprising a probe antenna for receiving the modulated electromagnetic wave and generating an output, and a demodulator for demodulating the electromagnetic wave received from the sensor to a digital record. A method of wirelessly communicating between a probe and a remote sensor is also disclosed.

Abstract: A system for communicating between a first location and a second location comprises a jointed tubular string having a first section and a second section connected at a connection joint, with the tubular string having a fluid in an internal passage thereof. A first acoustic transducer is mounted in the internal passage of the first section proximate the connection joint, and a second acoustic transducer is mounted in the internal passage of the second section proximate the connection joint. A signal transmitted from the first location to the second location is transmitted across the connection joint as an acoustic signal in the fluid from the first acoustic transducer to the second acoustic transducer.

Abstract: A method for determining electrical condition of a wired drill pipe includes inducing an electromagnetic field in at least one joint of wired drill pipe. Voltages induced by electrical current flowing in at least one electrical conductor in the at least one wired drill pipe joint are detected. The electrical current is induced by the induced electromagnetic field. The electrical condition is determined from the detected voltages.

Abstract: A pressure pulse generator for use in transmitting pressure signals to surface in a fluid-based drilling system having a housing having an inlet to admit drilling fluid to the interior of housing, and an outlet to discharge fluid from the interior of the housing; a control element slidably mounted in the housing between an open and a closed position, the control element generating a pressure pulse in the supply of pressure fluid when the control element takes-up the closed position; a control passage extending through the control elements and closable by a pilot valve element exposed to the pressure of the fluid in the passage; and an actuator coupled with the valve element to generate a pressure signal, to move the valve element to a position closing said passage and thereby to cause movement of the control element towards the closed position; the coupling between the actuator and the valve element includes a yieldable biassing element which provides control of the amplitude of the pressure signals produces

Abstract: Methods and apparatus for receiving a telemetry signal with a receiver that is moveably disposed within a drillstring. In certain embodiments, the system comprises a surface module coupled to the upper end of a drillstring, an upper module detachably connected to the surface module, and a lower module moveably disposed within the drillstring. The lower module is coupled to the upper module by an extendable cable. A telemetry signal receiver is disposed on said lower module, which also includes a tractor assembly for moving the lower module through the drillstring.

Abstract: An inductive coupling system including a mandrel and an inner sleeve and outer housing that surround and rotate relative to the mandrel. The system also includes a mandrel electronics system and a housing electronics system that communicate electronically using a mandrel inductive coupler and a housing inductive coupler. The mandrel electronics system may also communicate with equipment on the surface. Alternatively, the system may include a mandrel and first and second mandrel electronics systems in different mandrel sections. The first and second mandrel electronics systems communicate electronically using a mandrel inductive coupler. Also alternatively, the system may include a mandrel and an inner sleeve and outer housing that surround and rotate relative to the mandrel. The system also includes a mandrel electronics system and a housing electronics system that communicate electronically using a housing inductive coupler.

Abstract: A shear coupled acoustic telemetry system. An acoustic telemetry system includes a tubular string having a pressure-bearing wall and an acoustic telemetry assembly positioned external to the wall and operative to communicate an acoustic signal between the assembly and the wall. The assembly may be shear coupled to the wall. The assembly may include a pressure-bearing housing positioned external to the wall.

Abstract: A rotary pulser for transmitting information to the surface from down hole in a well by generating pressure pulses encoded to contain information. The pressure pulses travel to the surface where they are decoded so as to decipher the information. The pulser includes housing containing a stator forming passages through which drilling fluid flows on its way to the drill bit, a rotor, and a replaceable wear sleeve enclosing the rotor. The rotor has blades that are capable of imparting a varying obstruction to the flow of drilling fluid through the stator passages depending on the circumferential orientation of the rotor, so that rotation of the rotor by a motor generates the encoded pressure pulses.

Abstract: Thin flexible piezoelectric transducers are bonded to or imbedded into oilfield tubular members or structural members. The transducers may be used to telemeter data as acoustic waves through the members. By proper spacing of transducers and phasing of driving signals, the transmitted signals can be directionally enhanced or encoded to improve transmission efficiency. The transducers may be used for health monitoring of the tubular or structural members to detect cracks, delaminations, or other defects. The flexible transducers are very thin so that overall dimensions of tubular or structural members are essentially unchanged by incorporation of the transducers.

Abstract: Acoustic telemetry systems and methods with surface noise cancellation. One illustrative embodiment may include an acoustic telemetry system comprising a transmitter configured to generate an acoustic information signal that propagates along a drillstring, and a receiver configured to detect an acoustic receive signal from the drillstring and a noise signal from a surface environment. The receiver operates on the acoustic receive signal and the noise signal to produce a modified signal indicative of the acoustic information signal and having a reduced noise content relative to the acoustic receive signal.

Abstract: An oscillating valve driven by the pressure in a mud pulser develops a pressure variation in the mud pulse signal that is at a frequency that is different than the frequencies of the mud system. The oscillating valve is coupled to or integral with the pulse drive cylinder, whether the drive means for operation of the pulser is upstream or downstream from the orifice. A bistable valve improves performance of the transmitting element at low flow rates by providing a toggle mechanism which assures positive seating of the bistable valve.

Abstract: Method systems and apparatus for signalling within pipelines. The systems methods and apparatus make use of a unit locatable within a tubular piece of metallic structure for the transmission and/or reception of signals. The unit includes a magnetic material core (6) which provides a path for magnetic flux through the unit (4). A coil (81) is wound around a portion of the magnetic material core (6) to allow the detection and/or application of magnetic flux in the magnetic core (6). At each end of the core (6) there is pair of arms (63) which are arranged for location adjacent the inside surface of the tubular structure. In use magnetic signals flowing in the tubular structure pass through the core (6) and can be detected via the coil (81) in receive mode and similarly signals flowing in the coil (81) can cause magnetic flux to flow through the core (6) and into the metallic structure in transmit mode.

Abstract: One embodiment includes a method comprising receiving an acoustic signal that is propagated along a drill string. The method also includes correlating the acoustic signal to a first stored acoustic signal representing a first symbol, wherein the first stored acoustic signal is acquired from a propagation along the drill string in an approximately noise free environment.

Abstract: A downhole communication apparatus has a signal coupler disposed in an end of a downhole tubular component. The signal coupler has a transceiver portion and a conductor portion. A data conductor integrated into the downhole tubular component is operably connected at a junction to the conductor portion of the signal coupler. A peripheral electronic device is in communication with the conductor portion of the signal coupler, either through an electrical coil wrapped around at least part of the conductor portion of the signal coupler or direct electrical contact with the conductor portion of the signal coupler.

Abstract: A method for downlink communication with a downhole tool having a mud-powered downhole motor that includes receiving a sensor signal related to a rotational speed of a rotor in the mud-powered downhole motor, and interpreting the sensor signal to derive a downlink signal.

Abstract: The invention is a system for transmitting data through downhole environments comprising a downhole network integrated into a downhole tool string. The downhole tool string comprises a plurality of downhole components. Each downhole component also comprises a conductor intermediate and operably connected to mating communication elements proximate the ends of the downhole component. The mating communication elements comprise magnetically conductive portions with different curie temperatures. The magnetically conductive portion may comprise segments or solid portions adapted to operate in the harsh downhole environments with temperatures ranging from 25 C to 275 C. Each downhole component is selected from the group consisting of drill pipes, drill collars, bottom hole assemblies, reamers, jars and/or production pipes.

Abstract: A system for loading an executable code into volatile memory in a downhole tool string component comprises a surface control unit comprising executable code. An integrated downhole network comprises data transmission elements in communication with the surface control unit and the volatile memory. The executable code, stored in the surface control unit, is not permanently stored in the downhole tool string component. In a preferred embodiment of the present invention, the downhole tool string component comprises boot memory. In another embodiment, the executable code is an operating system executable code. Preferably, the volatile memory comprises random access memory (RAM). A method for loading executable code to volatile memory in a downhole tool string component comprises sending the code from the surface control unit to a processor in the downhole tool string component over the network. A central processing unit writes the executable code in the volatile memory.

Abstract: Methods and systems employing combined source-channel coding for multi-carrier modulation (MCM). In some embodiments, a described method comprises: estimating channel gain to noise ratio (CGNR) as a function of frequency bin; determining MCM parameters that minimize distortion of one or more telemetry signals; generating a communications signal using the MCM parameters, and transmitting the communications signal via a communications channel. The MCM parameters may be determined by minimizing a telemetry signal distortion measure subject to CGNR and a transmit power constraint. The MCM parameters may further account for differing fidelity requirements when multiple telemetry signals are being transmitted.

Abstract: A reservoir production control system includes a plurality of wells for producing a reservoir linked to a central computer over a downhole communication network and a surface communication network. Both the downhole and the surface communication networks are wireless communications paths for transmitting downhole data and surface data to the central computer. Both networks include a series of interconnected tubing or pipe that allows transmission of data over electrically isolated portions of the pipe and tubing. After integrating and analyzing all relevant data and comparing the data with a reservoir model, the central computer initiates changes in a plurality of downhole control devices associated with the wells, thereby optimizing the production of the reservoir.

Abstract: A tool generates signals indicative a shear wave slowness of the formation surrounding a borehole. The tool comprises a collar portion adapted for mounting in a drill string, a quadrupole sonic transmitter mounted to the collar portion, and a quadrupole sonic receiver array mounted to the collar spaced apart from the transmitter. A method determines shear wave slowness of the formation. The method includes propagating quadrupole wave energy into the formation and detecting quadrupole dispersive waveform received at a second location. Formation shear wave slowness is calculated using dispersive slowness time coherence processing.

Abstract: A telemetry system having: a pipe; a SCADA box acoustically coupled to the pipe; and a gauge inserted in the pipe, the gauge comprising: an acoustic wave generator; a coupler mechanically connected to the acoustic wave generator, wherein the coupler is engageable and disengageable with the pipe, wherein the coupler defines an acoustic transmission path between the acoustic wave generator and the pipe when engaged with the pipe; and a signal controller in communication with the acoustic wave generator. A method for communicating information in a wellbore from a downhole location to the surface, the method having the following steps: running a downhole gauge into a pipe within the wellbore, wherein the downhole gauge comprise an acoustic wave generator; setting the downhole gauge in the pipe; and communicating an acoustic signal between the downhole gauge and the pipe.

Abstract: A modulated reflectance well telemetry apparatus having an electrically conductive pipe extending from above a surface to a point below the surface inside a casing. An electrical conductor is located at a position a distance from the electrically conductive pipe and extending from above the surface to a point below the surface. Modulated reflectance apparatus is located below the surface for modulating well data into a RF carrier transmitted from the surface and reflecting the modulated carrier back to the surface. A RF transceiver is located at the surface and is connected between the electrically conductive pipe and the electrical conductor for transmitting a RF signal that is confined between the electrically conductive well pipe and the electrical conductor to the modulated reflectance apparatus, and for receiving reflected data on the well from the modulated reflectance apparatus.

Abstract: An apparatus in accordance with the invention may include a downhole tool and a data transmission path incorporated into the downhole tool. The data transmission path may include one or more contact surfaces providing electrical continuity to the data transmission path. To protect the contact surfaces from corrosion while maintaining electrical conductivity, a coating may be attached to one or more of the contact surfaces. The coating may include any of various materials that increase the corrosion-resistance of the underlying base metal, including but not limited to cobalt, nickel, tin, tin-lead, platinum, palladium, gold, silver, zinc, or combinations thereof.

Abstract: A compact, robust, wear resistant, and high performance electrically insulating gap sub for use with borehole EM Telemetry is disclosed. In one embodiment, the gap sub may include an externally threaded mandrel separated from an internally threaded housing by a dielectric material. Additionally, some embodiments may include an external gap ring for separating the upper and lower electrical halves of the sub which offers structural support, acts as the primary external seal, and provides an abrasion resistant non-conductive length on the exterior. Some embodiments may include torsion pins to prevent the possible unscrewing of the dielectric filled threaded sections should the dielectric material become damaged or weakened.

Abstract: A mud pulse telemetry system comprises a surface located fluid supply line having a drilling fluid flowing therein. A non-venting pulser is disposed in the drilling fluid in the supply line, and the non-venting pulser is adapted to generate pressure fluctuations in the flowing drilling fluid. A downhole receiver in hydraulic communication with the non-venting pulser is adapted to detect the pressure fluctuations in the drilling fluid. A method for transmitting pressure signals from a surface location to a downhole location in a wellbore, comprises disposing a non-venting pulser in a surface located fluid supply line having a drilling fluid flowing therein. The non-venting pulser is actuated to generate pressure fluctuations in the flowing drilling fluid according to a predetermined encoding scheme. The pressure fluctuations are detected with a downhole receiver in hydraulic communication with the non-venting pulser.