The AirLock™ system facilitates landing casing in horizontal wells, at nominal cost and without interrupting casing and cementing operations.
Unlike conventional float shoe systems, the AirLock™ seal allows the vertical casing section to be filled with fluid, while the lateral section remains air-filled and buoyant.
The enhanced buoyancy reduces sliding friction more than 50%, while the weight of the vertical section provides additional force to push the string all the way to the toe.
The simple and passive AirLock™ system consists of only two components: a seal collar installed in the casing string just above the radius section and a debris-trap installed in a casing connection just above the float shoe.
Both components are made up in the casing string during run-in. The seal collar contains a pressure-calibrated, breakable seal that locks air in the lower section while the upper section is run and filled with fluid.
After the casing is landed, surface pressure is increased to fragment the seal, leaving an unrestricted casing bore. Seal fragments are collected by the debris trap, and cementing operations proceed as usual.