Abstract: Abstract As the search for oil and gas reserves is extended to deeper water, conventional offshore exploitation methods become less attractive due to the high cost for fixed platforms. This has prompted consideration of subsea completion methods as an alternative development technique. Humble Oil and Refining Co. has conducted tests to develop technology and equipment needed for completion and production maintenance of satellite underwater wells in deep water. Results of this development program are presented. Introduction The development of offshore oil and gas fields has largely been conducted from permanent pile-supported platforms using directional drilling techniques. Wells are drilled through large diameter conductors and wellhead equipment is installed on the platform deck. Permanent-type platforms have been installed in water depths to 285 ft. As activity moves into deeper water, the investment required for fixed platforms increases rapidly. This has prompted consideration of alternate development techniques for deep water using floating drilling and subsea completion methods. Floating rigs have been widely used as a deep water exploratory tool and techniques and equipment are now in an advanced state of development. For example, Humble recently drilled an exploratory well from a floating vessel in 632 ft of water offshore California. Industry experience is rather limited, however, with the completion and production of underwater wells. Most have used adaptations of conventional land equipment and have been completed in water depths easily accessible to divers. The extension of offshore operations to the edges of the continental shelves, and even beyond, has accelerated interest in the use of subsea completion techniques. To provide the technology and equipment needed for the completion and production maintenance of satellite underwater wells in deep water, Humble has prompted development of an underwater well completion system, an underwater Christmas tree system, and the tools and techniques required for performing well servicing and simple workover operations from a remote location. All equipment has been designed for remote diverless installation and operation. As a part of this program, an off. shore underwater test well has been completed and production experience has been accumulated over an extended period. Underwater Well Completion System The well completion system for satellite underwater wells (Fig. 1) was designed so that routine production maintenance and simple workover operations could be performed from a remote location with access to the well tubing through the flowline. JPT P. 1049ˆ