Abstract: A straddle packer assembly for deployment in a wellbore in which the straddle packer assembly includes a mandrel on which is mounted a first inflatable element and a second inflatable element. A first end of the first inflatable element is fixed, while a second end slides on the mandrel. Both the first and second ends of the second inflatable element are slidable on the mandrel, and the first end of the second inflatable element is coupled to the second end of the first inflatable element. The inflatable elements are inflated separately, with the first inflatable element inflated first until it seats against the wellbore wall. As the first inflatable element expands radially and contracts axially, the second inflatable element moves in axial concert with the first inflatable element so as to maintain a fixed distance between the two inflatable elements.

Abstract: A straddle packer assembly for deployment in a wellbore in which the straddle packer assembly includes a mandrel on which is mounted a first inflatable element and a second inflatable element. A first end of the first inflatable element is fixed, while a second end slides on the mandrel. Both the first and second ends of the second inflatable element are slidable on the mandrel, and the first end of the second inflatable element is coupled to the second end of the first inflatable element. The inflatable elements are inflated separately, with the first inflatable element inflated first until it seats against the wellbore wall. As the first inflatable element expands radially and contracts axially, the second inflatable element moves in axial concert with the first inflatable element so as to maintain a fixed distance between the two inflatable elements.

Abstract: An apparatus to determine fluid viscosities downhole in real-time includes a housing and an excitation element positioned therein. Electrical circuitry provides a drive signal that excites an excitation element into rotational oscillations. A detector produces a response signal correlating to the detected oscillating movement of the excitation element. Circuitry onboard the apparatus utilizes the drive and response signals to determine the fluid viscosity.

Abstract: An apparatus to determine fluid viscosities downhole in real-time includes a housing and an excitation element positioned therein. Electrical circuitry provides a drive signal that excites an excitation element into rotational oscillations. A detector produces a response signal correlating to the detected oscillating movement of the excitation element. Circuitry onboard the apparatus utilizes the drive and response signals to determine the fluid viscosity.

Abstract: Disclosed is a downhole fluid resistivity sensor that includes a ceramic cylinder having a fluid-contacting surface, and at least four metal pins that penetrate a wall of the ceramic cylinder at axially-spaced locations. The pins are bonded to the ceramic to form a pressure seal. The sensor may include a circuit that injects current into a fluid via an outer two of the pins, and measures a resulting voltage via an inner two of the pins. The circuit may also provide an indication of fluid resistivity based at least in part on the resulting voltage. At each of the axially-spaced locations, a set of multiple pins may penetrate the wall to contact the fluid at circumferentially-spaced positions. The fluid-contacting surface may be an inner surface or an outer surface of the ceramic cylinder. A downhole fluid resistivity measurement method is also described.

Abstract: An apparatus to determine fluid viscosities downhole in real-time includes a housing and an excitation element positioned therein. Electrical circuitry provides a drive signal that excites movement of the excitation element. A detector produces a response signal correlating to the detected rotational or oscillating movement of the excitation element. Circuitry onboard the apparatus utilizes the drive and response signals to determine the fluid viscosity.

Abstract: Disclosed is a downhole fluid resistivity sensor that includes a ceramic cylinder having a fluid-contacting surface, and at least four metal pins that penetrate a wall of the ceramic cylinder at axially-spaced locations. The pins are bonded to the ceramic to form a pressure seal. The sensor may include a circuit that injects current into a fluid via an outer two of the pins, and measures a resulting voltage via an inner two of the pins. The circuit may also provide an indication of fluid resistivity based at least in part on the resulting voltage. At each of the axially-spaced locations, a set of multiple pins may penetrate the wall to contact the fluid at circumferentially-spaced positions. The fluid-contacting surface may be an inner surface or an outer surface of the ceramic cylinder. A downhole fluid resistivity measurement method is also described.