DEFENDER

Owner

Goods & Services

Downhole fluid-operated back pressure valves for connection along a fluid conduit, namely, a drill string, extending within an oil and gas well for preventing uphole conveyance of fluid and pressure along the fluid conduit; downhole fluid-operated back pressure valves for connection along a fluid conduit, namely, a stimulation fluid string, extending within an oil and gas well for preventing uphole conveyance of fluid and pressure along the fluid conduit; and downhole fluid-operated back pressure valves that are part of a drill string extending within an oil and gas well for preventing uphole conveyance of drilling fluid and pressure along the drill string