Paper: Wellheads for Multiple Zone Completions

The first duals which were the direct forerunners of the present multiple parallel string technology, were set in the latter part of 1952 in the South Texas tidal waters near Matagorda Island. These were clamp type duals set at about 5000 feet. Since that time, multiple string completions have demonstrated their feasibility and economy and they have become almost mandatory for off-shore programs. The downhole features of multiple completions such as packers, slide valves, tubing joint clearance, and the like, have been adequately covered in previous papers and literature. However, due to the rapidly changing state of the art and the almost infinite variety as to pipe sizes, working pressures, and types of completions, little has been published to date concerning wellheads for parallel multiple completion. The purpose here is to outline major design considerations and describe generally the equipment available. Concentric dual hookups will not be covered since the wellheads and Xmas trees differ little from single zone arrangements.