Valve arrangements for pressure testing tubing

摘要

Pressure testing apparatus 30 comprises tubing 10 and a housing 32 containing a valve 38 positioned to selectively close a longitudinal opening 34 therein. The valve is operated by a selectively controllable mandrel 44 which slides longitudinally within the housing 32. The valve may be a flapper valve, biassed to a closed position to prevent downward fluid flow, and may be opened by the mandrel 44 passing upwards through the opening 34. Ball or disk valves may be used instead. Movement of the mandrel is controlled by pressurised fluid passing through a control line 60 to an annular housing recess 52 where upward pressure is applied to an annular flange 50 mounted on the mandrel. A spring-loaded lock pin 62 is actuated once the valve is fully open, maintaining it in the open state. Fluid from the control line 60 is also used to actuate a packer 66 situated above the valve. The pressure required to do this is higher than that needed to open the valve, so that the packer is actuated only once the valve has been opened. A further increase in pressure may burst a rupture valve 82, allowing fluid to be injected into the tubing 10. The mandrel 44 may alternatively be activated by an intelligent remote implementation system (IRIS) (129, figure 4) or, in event of a system failure, by means of a mechanical latch (128, figure 3), pulled from above by insertion of a suitable tool. An indexer (90, figure 3) can be used to activate the mandrel after a predetermined number of pressure tests.