Abstract: Systems and methods for managed pressure cementing and/or completions operations in subterranean well bores are provided. In some embodiments, the methods comprise: placing a tubular string into a well bore, wherein an outer surface of the tubular string and an inner wall of the well bore define an annulus in a closed pressure loop and in communication with a choke valve; pumping a fluid into the annulus; and while pumping the fluid, determining a setpoint for the choke valve corresponding to a setpoint for a bottomhole pressure in the annulus, determine an actual bottomhole pressure in the annulus using data from a downhole sensor in the annulus, determining if the actual bottomhole pressure is greater than, less than, or equal to the setpoint, and if the actual bottomhole pressure is greater or less than the setpoint, manipulating the choke valve using a controller to decrease or increase the bottomhole pressure.

Abstract: Switchable multi-antenna fluid sensing systems and methods, including a tubular-mounted switchable multi-antenna fluid sensing system that includes two antenna arrays that each senses fluid characteristics not sensed by other antenna arrays, each array including multiple antenna sub-arrays and each sub-array including a receive and transmit antenna with a radial transmission direction different from that of other sub-arrays. The system also includes two RF multiplexers, each coupled to the antennas within the arrays and to corresponding RF transceivers within a sensor tube. A CPU within the sensor tube couples to the RF transceivers, controls signal transmission by, and processes received signals from, the antennas. RF cables coupling the RF transceivers and RF multiplexers are grouped and routed through one end of the sensor tube. The CPU further causes the RF multiplexers to periodically couple to the antennas and stores and/or transmits data representing the received signals.

Abstract: Systems and methods for signaling the detection of a fluid change in a wellbore can be used during wellbore operations, such as cementing a casing in the wellbore. The systems and methods involve using burst discs to provide a pressure pulse that can be detected uphole and there by provide a signal related to when a fluid change has reached a predetermined position in the wellbore. The burst discs can be activated to prevent fluid flow in a portion of the wellbore by a sensor that detects a property that is different between two fluids. Once activated, the pressure of the fluid on the burst discs subsequently ruptures the burst disc and creates the pressure pulse.

Abstract: Systems and methods for signaling the detection of a fluid change in a wellbore can be used during wellbore operations, such as cementing a casing in the wellbore. The systems and methods involve using burst discs to provide a pressure pulse that can be detected uphole and there by provide a signal related to when a fluid change has reached a predetermined position in the wellbore. The burst discs can be activated to prevent fluid flow in a portion of the wellbore by a sensor that detects a property that is different between two fluids. Once activated, the pressure of the fluid on the burst discs subsequently ruptures the burst disc and creates the pressure pulse.

Abstract: Systems and methods for managed pressure cementing and/or completions operations in subterranean well bores are provided. In some embodiments, the methods comprise: placing a tubular string into a well bore, wherein an outer surface of the tubular string and an inner wall of the well bore define an annulus in a closed pressure loop and in communication with a choke valve; pumping a fluid into the annulus; and while pumping the fluid, determining a setpoint for the choke valve corresponding to a setpoint for a bottomhole pressure in the annulus, determine an actual bottomhole pressure in the annulus using data from a downhole sensor in the annulus, determining if the actual bottomhole pressure is greater than, less than, or equal to the setpoint, and if the actual bottomhole pressure is greater or less than the setpoint, manipulating the choke valve using a controller to decrease or increase the bottomhole pressure.

Abstract: Switchable multi-antenna fluid sensing systems and methods, including a tubular-mounted switchable multi-antenna fluid sensing system that includes two antenna arrays that each senses fluid characteristics not sensed by other antenna arrays, each array including multiple antenna sub-arrays and each sub-array including a receive and transmit antenna with a radial transmission direction different from that of other sub-arrays. The system also includes two RF multiplexers, each coupled to the antennas within the arrays and to corresponding RF transceivers within a sensor tube. A CPU within the sensor tube couples to the RF transceivers, controls signal transmission by, and processes received signals from, the antennas. RF cables coupling the RF transceivers and RF multiplexers are grouped and routed through one end of the sensor tube. The CPU further causes the RF multiplexers to periodically couple to the antennas and stores and/or transmits data representing the received signals.

Abstract: Various disclosed distributed acoustic sensing (DAS) based systems and methods include embodiments that process the DAS measurements to detect one or more contrasts in acoustic signatures associated with one or more fluids flowing along a tubing string, and determine positions of the one or more contrasts as a function of time. The detected contrasts may be changes in acoustic signatures arising from one or more of: turbulence, frictional noise, acoustic attenuation, acoustic coupling, resonance frequency, resonance damping, and active noise generation by entrained materials. At least some of the contrasts correspond to interfaces between different fluids such as those that might be pumped during a cementing operation.

Abstract: Various disclosed distributed acoustic sensing (DAS) based systems and methods include embodiments that process the DAS measurements to detect one or more contrasts in acoustic signatures associated with one or more fluids flowing along a tubing string, and determine positions of the one or more contrasts as a function of time. The detected contrasts may be changes in acoustic signatures arising from one or more of: turbulence, frictional noise, acoustic attenuation, acoustic coupling, resonance frequency, resonance damping, and active noise generation by entrained materials. At least some of the contrasts correspond to interfaces between different fluids such as those that might be pumped during a cementing operation.

Abstract: Various disclosed cement slurry monitoring methods include monitoring one or more parameter of the cement slurry at various positions along the borehole during the curing process and responsively identifying a span over which the slurry extends and whether there are any gaps or voids in that span. At least some system embodiments include a distributed sensing arrangement to provide parameter measurements as a function of position and time during the curing process. A computer analyzes the measurements to determine the span of the cement slurry and whether any gaps exist. Contemplated measurement parameters include temperature, pressure, strain, acoustic spectrum, acoustic coupling, and chemical concentration. Individually or in combination, these measurements can reveal in real time the state of the cement slurry and can enable remedial actions to be taken during or after the curing process if needed to address deficiencies in the annular seal being provided by the cement.

Abstract: A method of controlling a well operation can include monitoring at least one parameter of cement lining a wellbore, the monitoring being performed via at least one optical waveguide, and modifying the well operation in response to the parameter being outside of a predetermined acceptable range. A well monitoring system can include at least one optical waveguide which is used to sense at least one parameter of cement lining a wellbore, an optical interrogation system optically connected to the at least one optical waveguide, and a control system which controls operation of at least one item of well equipment in response to information received from the optical interrogation system.

Abstract: Various disclosed cement slurry monitoring methods include monitoring one or more parameter of the cement slurry at various positions along the borehole during the curing process and responsively identifying a span over which the slurry extends and whether there are any gaps or voids in that span. At least some system embodiments include a distributed sensing arrangement to provide parameter measurements as a function of position and time during the curing process. A computer analyzes the measurements to determine the span of the cement slurry and whether any gaps exist. Contemplated measurement parameters include temperature, pressure, strain, acoustic spectrum, acoustic coupling, and chemical concentration. Individually or in combination, these measurements can reveal in real time the state of the cement slurry and can enable remedial actions to be taken during or after the curing process if needed to address deficiencies in the annular seal being provided by the cement.

Abstract: A method of controlling a well operation can include monitoring at least one parameter of cement lining a wellbore, the monitoring being performed via at least one optical waveguide, and modifying the well operation in response to the parameter being outside of a predetermined acceptable range. A well monitoring system can include at least one optical waveguide which is used to sense at least one parameter of cement lining a wellbore, an optical interrogation system optically connected to the at least one optical waveguide, and a control system which controls operation of at least one item of well equipment in response to information received from the optical interrogation system.