This paper was prepared for the SPE-European Spring Meeting 1974 of the Society of Petroleum Engineers of AIME, held in Amsterdam, the Netherlands, May 29–30, 1974. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Netherland Section of the Society of Petroleum Engineers, P. O. Box 228, The Hague, the Netherlands. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. Abstract A subsea completed oil well lying offshore Congo was brought into production with the aid of a 48 m × 16 m barge carrying production, stimulation and wire line production, stimulation and wire line equipment. The success of the operation was mainly due to the use of a subsea lubricator and associated barge-mounted swell compensating device. The feasibility of bringing subsea completed wells into production working from a floating support was amply demonstrated by this successful operation. Introduction The great majority of wellheads in offshore fields either producing or under development are installed above the surface of the sea on fixed platforms. In water depths of 70/100 m (230/330 ft) and over, the installation of such platforms is difficult and very costly. For this reason, when possible, deviated wells are drilled so as to group together a large number of wells, up to 25 or 30, on one platform. This solution cannot always be adopted, however, as for example in the case of shallow pay zones, where deviated wells would not drain a sufficiently large area. It was obvious that alternative methods of developing such offshore fields would have to be sought using wellheads installed on the sea bed. In fact in very deep water this would appear to be the only practicable method of producing. Such subsea completions could use "wet" type wellheads either with or without temporary capsule or "dry" wellheads with permanent capsule. The system we present is for use on the "wet" type of wellhead.