Abstract: A system and method for sensing leakage across a packer in a well, according to which a sensor is disposed in the well for sensing a characteristic of the packer such as vibrations, and a corresponding signal is outputted that is indicative of whether there is any fluid leakage across the device.

Abstract: The present disclosure addressed apparatus and methods for forming an annular isolator in a borehole after installation of production tubing. Annular seal means are carried in or on production tubing as it is run into a borehole. In conjunction with expansion of the tubing, the seal is deployed to form an annular isolator. An inflatable element carried on the tubing may be inflated with a fluid carried in the tubing and forced into the inflatable element during expansion of the tubing. Reactive chemicals may be carried in the tubing and injected into the annulus to react with each other and ambient fluids to increase in volume and harden into an annular seal. An elastomeric sleeve, ring or band carried on the tubing may be expanded into contact with a borehole wall and may have its radial dimension increased in conjunction with tubing expansion to form an annular isolator.

Abstract: A power generating system (100) for a downhole operation (10) having production tubing (40) in a wellbore (12) includes a magnetized rotation member (110) coupled to the wellbore (12) within the production tubing (40), the rotation member (110) having a passageway (112) through which objects, such as tools, may be passed within the production tubing (40). Support braces (170, 172) couple the rotation member (110) to the production tubing (40) and allow the rotation member (110) to rotate within the production tubing (40). Magnetic pickups (150, 152) are predisposed about the rotation member (110) within the wellbore (12) and a power conditioner (200) is provided to receive currents from the magnetic pickups (150, 152) for storage and future use.

Abstract: A system and method for dynamically calibrating signals from a quartz pressure sensor to correct for temperature transients. A series of differences of time spaced temperature readings is stored in a tapped delay line and coupled to a transfer function. The transfer function uses the temperature difference values to correct pressure frequency readings for temperature transient errors. In one form, one transfer function uses temperature and pressure readings to statically calibrate pressure readings and a second transfer function uses temperature differences to provide a temperature transient correction which is added to the statically calibrated pressure value.

Abstract: A hydraulic control and actuation system for downhole tools. In a described embodiment, a hydraulic control and actuation system includes an internal chamber serving as a low pressure region and a well annulus serving as an energy source. A valve assembly provides selective fluid communication between alternating opposite sides of a piston and each of the energy source and low pressure region. Displacement of the piston operates a well tool. Operation of the valve assembly is controlled via telemetry between a remote location and an electronic circuit of the system.

Abstract: An apparatus and method for monitoring and reporting downhole bit failure. Sensors are located on a sub assembly (which is separate from the drill bit itself but located above it on the drill string). Strain measurements are taken from the sensors to detect changes in induced bending and axial stresses which are related to a roller cone bearing failure. As a cone begins to fail, the average share of the total load on the bit that the failing cone can support changes, which causes a change in the bending strain induced by the eccentric loading of the cone.

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 system and method for dynamically calibrating signals from a quartz pressure sensor to correct for temperature transients. A series of differences of time spaced temperature readings is stored in a tapped delay line and coupled to a transfer function. The transfer function uses the temperature difference values to correct pressure frequency readings for temperature transient errors. In one form, one transfer function uses temperature and pressure readings to statically calibrate pressure readings and a second transfer function uses temperature differences to provide a temperature transient correction which is added to the statically calibrated pressure value.

Abstract: The present invention provides a self-contained sensor module for use in a subterranean well that has a well transmitter or a well receiver-associated therewith. In one embodiment, the sensor module comprises a housing, a signal receiver, a parameter sensor, an electronic control assembly, and a parameter transmitter; the receiver, sensor, control assembly and transmitter are all contained within the housing. The housing has a size that allows the module to be positioned within a formation about the well or in an annulus between a casing positioned within the well and an outer diameter of the well. The signal receiver is configured to receive a signal from the well transmitter, while the parameter sensor is configured to sense a physical parameter of an environment surrounding the sensor module within the well. The electronic control assembly is coupled to both the signal receiver and the parameter sensor, and is configured to convert the physical parameter to a data signal.

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: An electromechanical transducer formed by an electrical and mechanical combination of a piezoelectric device and a magnetostrictive device. The two devices are electrically coupled so that their capacitive and inductive reactances approach a balance to provide an essentially resistive combined input at a selected frequency. Efficiency of circuits driving the transducer is improved. The devices are mechanically coupled so that the mechanical outputs add or reinforce each other. Two transducer pairs may be used in a two frequency telemetry system with each pair tuned to one of the frequencies for optimal reactance balancing and transduction efficiency.

Abstract: Apparatus and methods for webserver-based well instrumentation, logging, monitoring and control provide convenience and economy in well site and off-site operations. In a described embodiment, a well tool includes a webserver connected to a sensor and an actuator of the tool. In response to a condition sensed by the sensor, a person utilizing a network to access a web page supported by the webserver at a remote location may operate the actuator to control operation of the well tool.

Abstract: Methods of expanding well tools, which permit operation of the well tools after expansion, are provided. In a described example, a cementing tool includes a valve and a packer. After the cementing tool is expanded, the valve is selectively opened and closed, and the packer is sealingly engaged in a wellbore.

Abstract: Methods are provided for downhole sensing and flow control utilizing neural networks. In a described embodiment, a temporary sensor is positioned downhole with a permanent sensor. Outputs of the temporary and permanent sensors are recorded as training data sets. A neural network is trained using the training data sets. When the temporary sensor is no longer present or no longer operational in the well, the neural network is capable of determining the temporary sensor's output in response to the input to the neural network of the permanent sensor's output.

Abstract: A screen assembly (38) and method for progressively treating an interval (48) of a wellbore (32) is disclosed. The screen assembly (38) comprises a sand control screen (40) that is positioned within the wellbore (32) and a plurality of diverter members (42) that are positioned along the sand control screen (40). During a treatment process when a treatment fluid is pumped into the interior of the sand control screen (40), the diverter members (42) progressively allow the treatment fluid to exit from the interior of the sand control screen (40) to the exterior of the sand control screen (40) from a first end (46) of the interval (48) to a second end (44) of the interval (48) to progressively treat the interval (48) of the wellbore (32).

Abstract: Electrical power generators and methods of producing power in a subterranean well are provided. In a described embodiment, fluid flow through a fluid conduit causes a member to displace or vibrate. The displacement of the member is utilized to induce strain in a piezoelectric material, thereby causing the piezoelectric material to produce electricity. Various means may be used to create turbulence in the fluid flow, thereby increasing displacement of the member, resulting in increased power output from the generator.

Abstract: A downhole tool and method for determining the viscosity of a reservoir fluid, the tool including a passage having entry, intermediate and exit regions, in which the reservoir fluid flowing through the passage will have a lower Reynolds number in the intermediate region as compared to the entry region, the tool also including differential pressure gauge for measuring the differential pressure across the intermediate region, and either a velocity controller or fluid velocity meter, for either setting or measuring the fluid velocity.

Abstract: A hydraulic circuit construction for use in downhole tools. In a described embodiment, a fluid circuit construction includes first and second layers. At least one fluid-operative component is received in the first layer. A fluid passage is formed on a surface of the second layer. The passage is in fluid communication with the fluid-operative component. The second layer surface is sealingly attached to a surface of the first layer, so that the first layer surface closes off an outer side of the passage.

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 apparatus and method for monitoring and reporting downhole bit failure. Sensors are located on a sub assembly (which is removable from the drill bit) and send data to neural net or other adaptive filter. The neural net uses past sensor readings to predict future sensor readings. The value predicted for the sensors is subtracted from the actual value to produce a prediction error. Increases in prediction error are used to indicate bit failure. The results of this are transmitted to the operator by varying the pressure in the drilling mud flow.