This paper proposes a minimum structure to drill and appraise four oil/gas wells without installing a structural jacket. A structural template with conductor guides will be installed on seabed. The well conductors may be driven into the seabed by a hammer fitted to the jack-up rig-based crane. The conductors will support a small, prefabricated two-level deck (9m × 12m). The template is supported by customized mudmats to withstand the environmental loads without piled foundation. In case of a positive drilling outcome, a riser and a pipeline will be added to connect with the nearest subsea/onshore tie-in point to carry out well testing by flowing the wells. Based on the outcome of a prolonged well testing, installation of the remaining facilities will be undertaken. In Phase-2, a structural jacket will join the template and piles will be driven through the legs. The deck of the second phase will have internal opening to clear the existing topside (installed in Phase-1) during installation. The existing and the new decks will be joined at offshore. The platform has a provision for two future wells.

Numerical studies show that the Phase-1 structure can withstand omnidirectional environmental forces due to 10.4m high waves and Phase-2 structure can withstand 15.4m waves at 35m water depth. Structural design is performed using API RP2A working stress design method. The results show adequacy of the structure with required minimum reserve strength and prove that large amount of initial CAPEX can be avoided by carrying out well appraisal before installing full production facilities.

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