Full-opening, annulus pressure-operated valve designed for cased hole drill stem testing operations as the main tester valve. The LPR-N Valve enables multiple closed-in pressure measurements in cased holes where pipe manipulation is restricted and a full-opening string is required.

• Ball Valve Section: Contains ball valve and mechanical components for multiple downhole closures. Can be run in open or closed position depending on assembly.
• Power/Nitrogen Section: Features shear pins, operating piston, and nitrogen chamber with one side exposed to annulus pressure and the other to pressurized nitrogen.
• Metering Section: Isolated from annulus fluid by oil and floating piston barrier, controlling nitrogen chamber pressure change rate.

During testing initiation, pressure is quickly pumped to the annulus to predetermined levels and held for 10 minutes to pressurize the nitrogen chamber. After pressure metering, nitrogen chamber pressure remains slightly below combined hydrostatic and pump pressure, ensuring ball valve remains open during testing or treating operations.

Works with full bore retrievable packers, circulating valves, safety joints, downhole tester valves, select tester valves, LPR-N Valves, omni valves, multi-cycle circulating valves, hydraulic jars, shock absorbers, RD safety circulating valves, high pressure retrievable packers with bypass, CHAMP packers, IPO valves, tubing string test valves, sleeve type drain valves, rupture disk samplers, super safety valves with control panels, and BOP safety valves for downhole operations.