Abstract: A method, related device and system for lifting a reservoir fluid in an oil and gas well involves allowing the reservoir fluid to flow in an axial uphole direction through an internal flow path of a production tubing disposed in the well. The internal flow path includes a Venturi profile configured to flash out a free gas phase from the reservoir fluid as the reservoir fluid flows in the axial uphole direction through the Venturi profile, such that the reservoir fluid comprises the free gas phase and a liquid phase. The internal flow path also includes a diffusion profile disposed above the Venturi profile and configured to condense the free gas phase into the liquid phase as the reservoir fluid flows in axial uphole direction through the diffusion profile.

Abstract: A cable head for attaching a wireline to a downhole tool includes an upper tubular member and a lower tubular member removably attached by a threaded connection. The cable head includes a pack-off assembly disposed within the upper tubular member. The pack-off assembly includes a deformable pack-off element comprising an outer sidewall for sealing against an inner sidewall of the upper tubular member, and an inner sidewall for sealing around the wireline. The pack-off assembly includes a biasing means axially in line with the deformable pack-off element. The pack-off element and the biasing means are axially compressed between an internal shoulder of the upper tubular member and the lower tubular member when the upper and lower tubular members are removably attached by the threaded connection, to enhance the seal of the tubular pack-off element with the inner sidewall of the upper tubular member, and with the wireline.

Abstract: A flexible coupling for coupling sections of a downhole tubing string is provided. The flexible coupling has a central section with first and second ends, each end having a contact surface and a first part of a pivoting connector, the contact surface extending radially outward relative to the first part of the pivoting connector. The flexible coupling also has first and second coupling sections pivotally coupled to the first and second ends of the central section. Each of the first and second coupling sections have a tubing string attachment at a first end, a second part of the pivoting connector at a second end, and a contact surface at the second end, the contact surface extending radially outward relative to the second part of the pivoting connector. Pivotal movement of the first and second coupling sections relative to the central section is limited by engagement between the contact surfaces.

Abstract: A downhole packer includes a first locking member positioned at least partially around an outer surface of an oilfield tubular. The first locking member includes an inner surface that engages the outer surface of the oilfield tubular, and a tapered outer surface. A drive ring is positioned at least partially around the first locking member. The drive ring includes a reverse-tapered inner surface that engages the tapered outer surface of the first locking member. A first cap is movably coupled with the drive ring, disposed at least partially around the first locking member, and axially engaging the first locking member. Moving at least one of the first cap and the drive ring toward the other causes the drive ring to apply a radially-inward force on the first locking member, causing the first locking member to be secured to the tubular.