Reservoir Characterization And Reservoir Engineering Study Of Fula Field And Moga Field In Sudan

The production commenced in Fula field on Nov. 18, 2003, after 8 years exploration and development of Block 6 operated by CNPCIS with 100% working interest from 1995. The Fula and Moga Fields are main development area for the current 12000BOPD of Phase I and 40000BOPD of PhaseII by the end of 2005. On the base of detailed 3D seismic interpretation and comprehensive geological study, the structure, formation, reservoir feature, fluid potential and reservoir engineering are studied. The reservoir features are drscribed in detail and the rules of hydrocarbon accumulation are summarized. The progressive exploration and development were proposed and implemented. The cold heavy oil production with sand (CHOPS) were recommended and employed in the field production by the widely investigation in the world and result of reservoir engineering study for Fula and Moga fields. Fula and Moga Fields are mainly consisted of shallow ordinary heavy oil reservoirs in Cretaceous Aradeiba and Bentiu Formations and light oil and gas reservoirs in Cretaceous Abu Gabra Formation. Aradeiba layered reservoirs are located in thin sandstones of shallow lacustrine facies. The massive reservoirs distributed in thick sandstones braided river facies thick bedded are developed in the Bentiu Formation. The Aradeiba and Bentiu reservoirs are characterized by shallow burial depth, loose consolidation, good porosity and permeability, high sand production and low formation pressure, and the crude oils are characterized by high density, high viscosity, and high acid value. The layered Abu Gabra reservoirs are located in thin sandstone reservoirs with medium porosity and medium permeability of delta front facies, being characterized by small fault block, rapid facies change and low hydrocarbon column. Effective combination of source, reservoir and cap rock, lateral sealing of mudstones are the main control factors of oil and gas accumulations in Darfur Group and Bentiu Formation. The main trap types are fault nose and fault anticline. The main blocks are Block Fula North and Block Mog20. The reservoir in Bentiu Formation in Block Fula North is a faulted anticline in a horst block with a tilt oil water contact. The oil potential estimated by the seismic interval velocity indicates that there is the good match between the low fluid potential and oil accumulation. The success of the proposed satellite wells indicates the reserve potential area is in between Moga and Fula oil fields. The production performance is better than expected, the high production rate of Bentiu are supported by the thick pay zones and strong bottom water and the lower production rate of Aradeiba are caused by the thin pay zones and weak edge water.