This paper describes the experience and learning gained whilst, designing, planning and installing a Multi-Lateral Well on the Forties field operated by BP Exploration in the UKCS. This project was initiated by the Research and Development groups of BP Exploration and Halliburton Energy Services, and sponsored by the European Union's Joule-THERMIE Program which supports the implementation of technology in Europe. The objectives of the project were to drill and complete a dual lateral well with commingled production, at minimum risk and cost, and to monitor and report the production performance. The difference between this project and the majority of multi-lateral wells drilled to date will be the installation of a cemented junction with connectivity, isolation and re-entry capability. The successful execution of this project will provide the industry with data on the long term performance of a cased hole, cemented, junction design. It will also provide production performance from a dual lateral well and give details of the challenges facing the management of such a well in a mature field environment. It is anticipated that this will lead to increases in the application of this technology, improve the economical recoverable reserves from mature fields and reduce the cost of new fields.