Subsurface safety system

摘要

Disclosed is a method of inserting and removing tubular valves into and from the secondary bore of a mandral having a main bore and a laterally offset secondary bore. The method includes the steps of positioning a whipstock plug having a sloping upper surface in the main bore and orienting the whipstock plug such that the upper surface slopes toward the secondary bore. The valves are removed by deflecting a retrieving tool off the upper surface of the whipstock plug to engage and remove the tubular valve from the secondary bore. The valves are inserted by deflecting the valve off the upper surface and into the secondary bore. After removal or insertion of a valve, the whipstock plug is removed from the main bore.