APPARATUS AND METHOD FOR CEMENTING LINER

摘要

A method of cementing a liner in a well includes mounting a valve assembly that is biased in a closed position to a running tool assembly. The running tool assembly has a stinger inserted through the valve assembly, retaining the valve assembly in an open position. The stinger has a cement retainer releasably mounted to it. After lowering the running tool assembly into engagement with the liner string into latching engagement with a lower portion of the liner string. Afterward, the operator lifts the stinger from the valve assembly, causing the valve assembly to move to the closed position. The valve assembly blocks upward flow of fluid from the well conduit through the valve assembly in the event of leakage of the cement retainer.

主权项

1. A method of performing an operation on a well conduit, comprising:
(a) providing a valve assembly that has an open position and a closed position, the valve assembly having a tubular central body and being biased to the closed position; (b) providing a running tool assembly with a downward extending stinger passing through the valve assembly, the valve assembly being installed and fixed to the well conduit with the stinger extending through the valve assembly, the stinger sealingly engaged with an annular seal interface located between a pair of flapper valve elements of the valve assembly, holding the valve assembly in the open position, wherein the seal interface includes a seal in constant sealing engagement within an annular groove in the tubular central body of the valve assembly; (c) placing the running tool assembly and the valve assembly into engagement with the well conduit; (d) performing a selected operation on the well conduit with the running tool assembly, including pumping a fluid through the stinger holding the valve assembly in the open position; then (e) lifting the stinger from the valve assembly, causing the valve assembly to move to the closed position.