Strategically Directed Drilling: New Opportunity in Rejuvenating Mature Fields in Eastern Venezuela
Roberto Barbato, Hernan Betancourt, Rafael Rodriguez, and
Geologically deviated drilling is used as a strategy for discovering and/or developing reservoirs in mature fields. Detailed descriptions of undrained areas are required in order to determine not only the deviated well trajectory, but also possible volumes of oil to be recovered and its profitability. Water-flooded and bypassed oil areas need to be characterized also. Other very important factors to be determined, are structure closure and fault planes. Strikes and dips of fault planes must be calculated as accurate as possible. In other words a thorough characterization based in available geological and seismic data of the reservoirs to be penetrated is needed in order to assure success.
One way to apply this technique is to design and drill a well that will travel parallel to the closure fault plane in order to penetrate as many as possible reservoirs a long their structurally highest points. Vertically drilled wells might have left out some of the reservoirs, because while penetrating the main reservoir at its highest point, it might have penetrated the opposite side of the fault or through the downdip water-wet parts of other reservoirs.
One well was drilled in the Budare field and a second one in the Oficina field with excellent results. An additional production potential of 1,200 BOPD was obtained for the two fields and new reserves of 4 MMBO were discovered.
AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California