Abstract: A system and methods for providing optical, downhole data communication without requiring a light source in the downhole tool is disclosed. A carrier signal generated at the surface is sent to the downhole tool using an optical fiber. An optical modulator of the downhole tool uses data signals from a sensor to modulate the carrier signal based on the data signals. The modulated signal is transmitted to one or more optical receivers. The optical modulator can be coupled to the one or more optical receivers through the same optical fiber as the carrier signal generator, or one or more additional optical fibers.

Abstract: A system and methods for providing optical, downhole data communication without requiring a light source in the downhole tool is disclosed. A carrier signal generated at the surface is sent to the downhole tool using an optical fiber. An optical modulator of the downhole tool uses data signals from a sensor to modulate the carrier signal based on the data signals. The modulated signal is transmitted to one or more optical receivers. The optical modulator can be coupled to the one or more optical receivers through the same optical fiber as the carrier signal generator, or one or more additional optical fibers.

Abstract: A pressure-balanced acoustic-signal-receiving apparatus and methods therefor. The apparatus may comprise a first housing, a first actuator, a second housing, and a second actuator. The first housing may comprise a fluid chamber, a passage connecting a first and second portion of the fluid chamber, a tubular-contact assembly, an isolating member within the fluid chamber and coupled to the assembly, an acoustic-signal receiver within the isolating member and coupled to the assembly, and a communication member coupled to the receiver. A method for receiving an acoustic signal generated within a wellbore may comprise receiving the acoustic signal with a tubular-contact assembly, sensing the acoustic signal with an acoustic-signal receiver positioned within a fluid chamber and coupled to the assembly, equilibrating fluid pressures in the first and second portions of the fluid chamber, and transmitting information generated by the acoustic-signal receiver through a communication member.

Abstract: A pressure-balanced acoustic-signal-receiving apparatus and methods therefor. The apparatus may comprise a first housing, a first actuator, a second housing, and a second actuator. The first housing may comprise a fluid chamber, a passage connecting a first and second portion of the fluid chamber, a tubular-contact assembly, an isolating member within the fluid chamber and coupled to the assembly, an acoustic-signal receiver within the isolating member and coupled to the assembly, and a communication member coupled to the receiver. A method for receiving an acoustic signal generated within a wellbore may comprise receiving the acoustic signal with a tubular-contact assembly, sensing the acoustic signal with an acoustic-signal receiver positioned within a fluid chamber and coupled to the assembly, equilibrating fluid pressures in the first and second portions of the fluid chamber, and transmitting information generated by the acoustic-signal receiver through a communication member.

Abstract: A method for removing a sealing plug from a casing or a wellbore according to which a sealing plug is adapted to expand into engagement with the casing or the wellbore. A wireless signal is sent to the plug to cause the plug to lose its structural integrity and fall to the bottom of the wellbore.

Abstract: A method for removing a sealing plug from a casing or a wellbore according to which a sealing plug is adapted to expand into engagement with the casing or the wellbore. A wireless signal is sent to the plug to cause the plug to lose its structural integrity and fall to the bottom of the wellbore.

Abstract: A tool and a method for sealing a casing or a wellbore according to which a device is supported on a mandrel and expands into engagement with the casing or the wellbore. An explosive cutter is also supported on the mandrel and is adapted to explode to cut the mandrel and the device and release the engagement.

Abstract: A method for removing a sealing plug from a casing or a wellbore according to which a sealing plug is adapted to expand into engagement with the casing or the wellbore. A wireless signal is sent to the plug to cause the plug to lose its structural integrity and fall to the bottom of the wellbore.

Abstract: A tool positioning assembly for positioning downhole tools at desired locations within a wellbore. The current invention further provides methods for using a tool positioning assembly. The tool positioning assembly and methods for using the same reduce the number of downhole trips required to perform downhole operations.

Abstract: A method of indicating the release of a plug, such as a cementing plug for an oil or gas well, includes releasing a plug from a retained position in a tube system, and in response to releasing the plug, opening an electrical circuit to which the plug was connected in the retained position. The method also includes generating, in response to opening the electrical circuit, a plug release indicator signal. The indicator signal can be generated in response to, for example, a low frequency electromagnetic signal.

Abstract: An apparatus and method provide data security for battery backed memory during power up and power down. A reversing sequential power up and power down process is used to control the write process for the memory during the operating voltage transitions of power up and power down. The apparatus is combined in a housing with a microprocessor and a memory to provide an instrument for an oil or gas well.

Abstract: A self-contained downhole apparatus for being lowered into an oil or gas well to internally record samples of at least one environmental condition comprises three body sections linearly and releasably interconnected. One of the body sections is a selected one of a plurality of transducer housing sections. The selected transducer housing section is mechanically and electrically connected to a second body section containing microcomputer-operated signal processing circuitry. The third body section contains a power supply.

Abstract: A self-contained memory gauge includes either semiconductor or magnetic core memory for retaining downhole information related to sampled parameters, such as borehole temperature and pressure. A microprocessor-based computer manages the power utilization by independently and selectably energizing and de-energizing different sections of the gauge. The magnetic core memory is tested for operability, and the addressing of the magnetic core memory is adjusted in accordance with any inoperable memory locations. Samples of the monitored environmental conditions can be taken at variable rates dependent upon software monitoring of the condition, the remaining battery life and the remaining memory capacity and in response to hardware monitored pressure changes. Each sample can be taken to a selectable resolution. A watchdog circuit monitors the microprocessor to insure that it is operating within a preselected time limit.

Abstract: In a preferred embodiment, an eletronic temperature gauge is carried into a well bore within a pressure-sealed housing which can free fall through a drill string to impact upon a drill bit connected at the bottom of the drill string. A shock absorber is connected at the bottom of the housing to absorb the shock upon impact of the apparatus on the drill bit. The shock absorber has a relatively linearized shock absorbing response in the preferred embodiment. Additional structural features provide further cushioning of the gauge during transit and upon impact.

Abstract: In an oil well instrumentation system, the downhole sensor system is controlled by a computer which is powered-on only during sampling movement. An independent circuit, continuously powered, detects significant sensor rate-of-change values whereby the computer-sampling equipment is powered-on. A self-contained memory gauge includes either semiconductor or magnetic core memory for retaining downhole information related to sampled parameters, such as borehole temperature and pressure. A microprocessor-based computer manages the power utilization by independently and selectably energizing and deenergizing different sections of the gauge. The magnetic core memory is tested for operability, and the addressing of the magnetic core memory is adjusted in accordance with any inoperable memory locations.

Abstract: The power-conversing apparatus includes a plurality of independently energizable electrical circuits used in receiving electrical signals from a transducer which senses an environmental condition, in processing the electrical signals, and in storing information related to the detected environmental condition. The apparatus further includes a power control circuit for continuously providing electrical power to at least one of the electrical circuits and for independently switchably providing electrical power to selectable ones of at least two others of the separately energizable circuits.

Abstract: A method of testing a magnetic core memory includes writing a test bit to each storage location addressed by each X-drive/X-sink transistor pair and each Y-drive/Y-sink transistor pair to determine which transistor or transistors of each pair is or are inoperable. Once this determination is made, a memory status map is created designating the inoperable transistors. Thereafter, the map contents are converted into an address field for matching against a selected memory address. If the selected memory address calls for an inoperable transistor, as indicated by a comparison with the address field, this is detected and the address changed until only operable transistors are accessed.

Abstract: A physical condition in a well bore is sampled and information taken from the sample is recorded by a method of conserving electrical energy in performing such sampling and recording. The method sequentially energizes and de-energizes a plurality of different electrical circuits within the downhole apparatus with which the physical condition is detected and in which the information is recorded. The method determines when the next sample is to be taken and, depending upon how much time remains until the next sample, de-energizes the apparatus to conserve energy.