Abstract: A flapper valve assembly (120) for controlling fluid flow therethrough is disclosed. The flapper valve assembly (120) comprises a tubular valve housing having a valve chamber. A valve seat (124) is mounted within the housing. The valve seat (124) has a valve seat sealing surface (126). The valve seat (124) also has an internal load bearing shoulder (134). A flapper closure plate (122) is rotatably disposed within the valve chamber. The flapper closure plate (122) is rotatable between a valve open position in which the flapper closure plate (122) is removed from the valve seat (124) and a valve closed position in which the sealing surface (128) of the flapper closure plate (122) sealingly engages the valve seat sealing surface (126) for preventing flow through the flapper valve assembly (120). The maximum travel of the flapper closure plate (122) in the closed position is defined by the internal load bearing shoulder (134) of the valve seat (124).

Abstract: A downhole communications system including an electromagnetic-to-acoustic signal repeater (35) for communicating information between surface equipment and downhole equipment and a method for use of the repeater (35) is disclosed. The repeater (35) comprises an electromagnetic receiver (37) and an acoustic transmitter (41). The receiver (37) receives an electromagnetic input signal and transforms the electromagnetic input signal to an electrical signal that is inputted into an electronics package (39) that amplifies the electrical signal and forwards the electrical signal to the transmitter (41) that transforms the electrical signal to an acoustic output signal that is acoustically transmitted.

Abstract: An electromagnetic telemetry system for changing the operational state of a downhole device (84) disclose. The system comprises an electromagnetic transmitter (76) disposed in a first wellbore (30) that transmits a command signal. An electromagnetic repeater (68) disposed in a second wellbore (38) receives the command signal and retransmits the command signal to an electromagnetic receiver (96) disposed in a third wellbore (46) that is remote from the first wellbore (30). The electromagnetic receiver (96) is operably connected to the downhole device (84) such that the command signal received from the electromagnetic repeater (68) is used to prompt the downhole device (84) to change operational states.

Abstract: An apparatus and method for sampling downhole fluids comprising a tool (36) attached to a connector (34) that is locked into position within a pipe section (32) is disclosed. The pipe section (32) has a longitudinal slot (62) with first and second sides (78, 80). The pipe section (32) also includes a transverse slot (64) that extends perpendicularly from the first side (78) of the longitudinal slot (62) and a hole (66) that extends perpendicularly from the second side (80) of the longitudinal slot (62). The connector (34) is inserted into the hole (66) such that the connector (34) may be rotated between an insertion position and an operating position. The connector head (100) of the connector (34) is closely received within the longitudinal slot (62) such that when the connector (34) is in the operating position, the connector head (100) contacts the first side (78) of the longitudinal slot (62) to lock the connector (34) within the pipe section (32).

Abstract: A downhole pulling tool (100) for retrieving downhole devices (102, 104) from a wellbore is disclosed. The downhole pulling tool (100) includes a mandrel (106) and a sleeve (108) that is slidably disposed about the mandrel (106). The sleeve (108) is moveable in a first direction from a first position to a second position relative to the mandrel (106) and is moveable in a second direction from the second position to a third position relative to the mandrel (106). An engagement member (114) radially extends between the mandrel (106) and the sleeve (108) and is operated from a retracted position to an engagement position when the sleeve (108) is moved to the second position relative to the mandrel (106) after equalization.

Abstract: An electromagnetic downlink and pickup apparatus for transmitting and receiving electromagnetic signals is disclosed. The electromagnetic downlink and pickup apparatus includes a subsea conductor (47) disposed beneath the sea floor (16) and a surface installation (58) for generating and interpreting signals. The subsea conductor (47) and the surface installation (58) are electrically connecting by first and second conduits (30, 51) that form a pair terminals on the subsea conductor (47) between which a voltage potential may be established, thereby providing a path for current flow therebetween.

Abstract: A tortuous path sand control screen (40) for reducing the velocity of particles (66) traveling therethrough is disclosed. The tortuous path sand control screen (40) comprises a base pipe (42) and a screen wire (48) wrapped therearound having turns (50, 52, 54) which extend along at least a portion of the length of the base pipe (42) forming gaps between adjacent turns (50, 52). The screen wire has a profile (62, 64) that reduces the velocity of the particles (66) traveling through the gaps, thereby minimizing erosion of the tortuous path sand control screen (40).

Abstract: An apparatus for obtaining resistivity readings of the earth surrounding a wellbore (32) to determine the downhole location of the apparatus or to generate a log is disclosed. The apparatus comprises an electromagnetic transmitter (40) for transmitting electromagnetic waves (42, 46) into the earth and an electronics package (122). The electronics package includes a power source (200) providing a current to the electromagnetic transmitter (40), a current sensing device (204) for detecting the current drawn by the electromagnetic transmitter (40), a sample and hold circuit (210) for sampling the current drawn by the electromagnetic transmitter (40) and a memory device (214) for storing the current draw information.

Abstract: An electrohydraulic control unit for operating an actuator of a hydraulically controllable device is disclosed. The electrohydraulic control unit comprises a housing including a chamber for hydraulic fluid. The housing is coupled to the actuator such that a path for fluid communication between the chamber and the actuator is created. Disposed within the chamber is a piston for regulating the flow of the hydraulic fluid between the chamber and the actuator. An electric motor is securably attached to the housing. The electric motor includes a selectively rotatable shaft. The electrohydraulic control unit also comprises a converter configured to transform the rotational motion of the shaft to translational motion of the piston, thereby controlling the actuation of the hydraulically controllable device.

Abstract: An electrically insulating gap subassembly for inclusion in a pipe string (30) comprising a pair of tubular members (90, 98) having an electrically insulating isolation subassembly (94) threadably disposed therebetween is disclosed. The electrically insulating isolation subassembly (94) has an anodized aluminum surface that provides electrical isolation to interrupt electrical contact between the two tubular members (90, 98) such that electromagnetic waves (46, 54) carrying information may be generated thereacross.

Abstract: A sand control screen assembly (10) having a sacrificial anode (26) is disclosed. The sand control screen assembly (10) comprises a plurality of ribs (16) spaced around a base pipe (12) and a screen wire (18) wrapped around the plurality of ribs (16) forming adjacent turns (20, 22) having gaps therebetween that allow the flow of fluids therethrough while preventing the flow of particulate therethrough. The plurality of ribs (16) includes at least one rib (26) that comprises a first metal. The screen wire (18) comprises a second metal that is cathodic to the first metal such that the at least one rib (26) that comprises the first metal acts as a sacrificial anode to reduce the environmental cracking of the screen wire (18).

Abstract: An apparatus, method and system for communicating information between downhole equipment (40) and surface equipment is disclosed. The electromagnetic signal repeater apparatus (34, 36) comprises a housing (102) that is securably mountable to the exterior of a pipe string (30) disposed in a wellbore (32). The housing (102) includes first and second housing subassemblies (104, 106). The first housing subassembly (104) is electrically isolated from the second housing subassembly (106) by a gap subassembly (108) having a length that is at least two times the diameter of the housing (102). The first housing subassembly (104) is electrically isolated from the pipe string (30) and is secured thereto with a nonconductive strap (120). The second housing subassembly (106) is electrically coupled with the pipe string (30) and is secured thereto with a conductive strap (122). An electronics package (127) and a battery (126) are disposed within the housing (102).

Abstract: A seismic handling device for safely transporting, deploying, and retrieving a seismic unit on a sea vessel is disclosed. The seismic handling device comprises a plurality of vertical structural members extending from the vessel. A plurality of horizontal structural members are connected to the vertical structural members. A delivery system is securely attached to the horizontal structural members. The delivery system positions the seismic unit into the sea, tows the seismic unit during a survey and retrieves the seismic unit from the sea.

Abstract: A tamper-proof security device for preventing the unauthorized removal of an individual or asset from a secured area and a system for use with the same is disclosed. The device is attached to an individual or asset and comprises a transmitter having a transmitter circuit therein for generating a digitally encoded signal on a predetermined frequency. At least one wire is disposed within the device for creating continuity in the transmitter circuit when the device is attached to the individual or asset. A power source is disposed within the transmitter which is electrically connected to the transmitter circuit when a switching mechanism is operated, thereby activating the transmitter circuit. Once the transmitter circuit is activated, the transmitter circuit generates the digitally encoded signal in response to a discontinuity in the wire.

Abstract: An apparatus, method and system for communicating information between downhole equipment (40) and surface equipment is disclosed. The electromagnetic signal repeater apparatus (34, 36) comprises a housing (102) that is securably mountable to the exterior of a pipe string (30) disposed in a wellbore (32). The housing (102) includes first and second housing subassemblies (104, 106). The first housing subassembly (104) is electrically isolated from the second housing subassembly (106) by a gap subassembly (108) having a length that is at least two times the diameter of the housing (102). The first housing subassembly (104) is electrically isolated from the pipe string (30) and is secured thereto with a nonconductive strap (120). The second housing subassembly (106) is electrically coupled with the pipe string (30) and is secured thereto with a conductive strap (122). An electronics package (127) and a battery (126) are disposed within the housing (102).

Abstract: A subsea repeater apparatus (48) for communicating information between surface equipment (60) and downhole equipment (44) is disclosed. The apparatus (48) comprises an electromagnetic receiver (66, 68) that receives an electromagnetic signal (46) carrying information from downhole equipment (44) and an acoustic modem (54) that acoustically retransmits (56) the information to surface equipment (60) through the sea. The apparatus (48) may also comprise an acoustic modem (54) that receives an acoustic signal (64) carrying information from surface equipment (60) through the sea and an electromagnetic transmitter (50) that radiates electromagnetic waves (66) carrying the information into the earth.

Abstract: A tubing retrievable surface controlled subsurface safety valve 106 is adapted to be positioned in a well tubing string 102 to control the flow through the tubing string. The safety valve includes an annular housing or body 200 defining a fluid passageway through which fluids and/or gasses may flow to the surface. The safety valve is equipped with a valve closure member such as flapper 252, positioned in the fluid passageway which is moveable between an open and closed position. The valve closure member is engaged and actuated by a longitudinally extending operator 242 that engages the valve closure member 252. In one embodiment, the longitudinally extending operator 242 may be a tubular member longitudinally moveable within the valve body. The longitudinally extending member 242 is operatively coupled to a spring guide 226. A biasing spring 222 is positioned in a spring chamber 120 defined by a spring housing 228 and the spring guide 226. A spring 256 biases the closure member 252 in the closed position.

Abstract: An electromagnetic pickup device (64) for receiving electromagnetic signals (62) is disclosed that comprises an H-field probe (68) having an end (78) the is insertable into the earth (16) for receiving the H-field component of the electromagnetic signal (62) and a plurality of E-field probes (66) that are radially disposed about the H-field probe (68) and electrically isolated from the H-field probe (68), each having an end (76) that is insertable into the earth (16) for receiving the E-field component of the electromagnetic signal (62).

Abstract: A downhole electromagnetic signal repeater (76) for communicating information between surface equipment and downhole equipment and a method for use of the repeater (76) is disclosed. The repeater (76) comprises a receiver (120) and a transmitter (124). The receiver (120) receives an electromagnetic input signal and transforms the electromagnetic input signal to an electrical signal that is inputted into an electronics package (122) that amplifies the electrical signal and forwards the electrical signal to the transmitter (124) that transforms the electrical signal to an electromagnetic output signal that is radiated into the earth.

Abstract: A progressive gap sand control screen comprising a plurality of parallel ribs spaced around an axis and a screen wire wrapped around the plurality of ribs having turns which extend along the length of the plurality of ribs such that adjacent turns have gaps therebetween, the gaps forming a gap profile in which the gaps near the upper end of the sand control screen are narrower than the gaps near the lower end of the sand control screen, the width of the gaps near the upper end of the sand control screen being less than the diameter of the particles which cause erosion, the gap profile includes a variable gap section near the upper end of the sand control screen and a constant gap section below the variable gap section, the variable gap section having a linear profile, a step type profile, or a nonlinear profile.