Oil Field Development and Production from Deep-Water Reservoirs

Julio E. Gontijo

Planning and executing the development of oil fields located in deep waters has offered many new challenges. Conventional (shallow water) methodologies and technologies often cannot be applied or are unsatisfactory for obtaining desired performance.

In the big deep-water fields of the Campos Basin, offshore Brazil, PETROBRAS has efficiently combined the geophysics, geology, drilling, production, and reservoir engineering disciplines in an interactive manner, resulting in projects which are both technically feasible and economically attractive.

After field discovery, reliable seismic interpretation is key to reservoir delimitation and mapping, minimizing the number of extension wells. Development strategy then includes division of the overall project into modules or phases, starting with a pilot "mini-project," with procedures and decisions for future phases determined according to results obtained from previous phases. The main advantages of this strategy are:

-- the pilot "mini-project" provided important information about reservoir parameters and production operations (such as sand production control and paraffin deposition in the wells and flowlines), the oil processing system, and requirements for artificial lift or secondary recovery

-- risks are minimized

-- investments are distributed over time

-- production revenue obtained from initial phases contributes to financing of future phases

Technologies currently utilized include wet christmas trees, flexible submarine flowlines, submarine manifolds, and various types of floating production systems. New deep-water technologies to be implemented in the near future include submarine multiphase pumping, submarine centrifugal submersible pumping, submarine produced fluid separation and non-conventional wells (horizontal, coiled tubing wells, etc.).

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995