Delayed acting gravel pack fluid loss valve

摘要

A fluid loss valve is disposed in a wash pipe in a gravel packing assembly. It is preferably held open initially and when in the process it is time for the valve to be able to go closed a pulling force is applied that creates relative movement to either close the valve or allow it to close without release of the assembly when under tension. This allows a surface signal that the valve is to be released for closure. The tension is relieved before string movement with the valve can occur. This can happen by slacking off before picking up again or through other time delay features that allow the tension to be removed and a lock to collapse before a lift force is applied for subsequent gravel packing operations. The valve in its closed position acts to eliminate fluid loss when excess gravel is reversed out.