Patent ID: 7971639

Claim:
A cementing or inflow regulation valve for conducting cementing operations or inflow regulation in a wellbore including a casing or tubing, wherein the cementing or inflow regulation valve is inserted between the casing or tubing; the cementing or inflow regulation valve comprising an inner sliding sleeve valve slidable between a closed position at which the inner sliding sleeve valve covers a plurality of openings defined on an outer pipe of the casing or tubing and an open position at which said openings are not covered by the inner sliding sleeve valve, the sliding sleeve valve comprising a releasing means for requiring a certain force in order to slide the inner sliding sleeve valve both from the closed position to the open position, and vice versa; wherein when the sliding sleeve is in the closed position, a sealed chamber is formed between the sliding sleeve valve and the outer pipe of the cementing or inflow regulation valve, the sealed chamber being killable with a fluid to prevent ingress of undesired drilling and formation fluids and solids; wherein sealing elements are provided in the openings of the outer pipe of the cementing or inflow regulation valve to prevent ingress of any solids, fluids and cement located inside or outside the casing or tubing; and wherein the sealing elements comprise plugs installed in the openings and pressure balancing means for preventing a pressure difference across the plugs from exceeding a limit.