Lock open and control system access apparatus and method for a downhole safety valve

摘要

A lock open device for a flapper is disclosed. The tool engages in the sub-surface safety valve (SSSV) body and rotates the flapper to the open position, without shifting the flow tube. The flapper base is preferably held by a shearable thread and has a groove for engagement by the tool. The tool jars down on the flapper base to shear the thread and force the held open flapper into a retaining groove. Optionally, a penetrating tool can be connected so that, in a single trip, the flapper can be locked open and the pressurized control system can be accessed. Shearing the thread allows the flow tube spring to bias the held open flapper into its retaining groove.