Structural and Stratigraphic 3D Seismic Interpretation of Middle Cretaceous in South East Muglad Basin, Sudan
Saror, Dorar Hamdoba Elshaikh
In this study, the structural system, and the seismic interpretation of Middle Cretaceous South East Muglad basin in JK Field were interpreted using 3-D seismic data volume, well logs and seismic attribute. The main use of seismic attributes was to create an intuitive display that allows an interpretation task to be performed both more efficiently and more effectively to characterize structural and depositional settings of JK field South East Muglad basin.
To demonstrate structural settings of the study area 3D seismic data were interpreted. Three main seismic reflectors, three horizons were picked. The most dominant structure in the area was the North North West, South South East trending normal faults and North East South West trending minor normal faults were developed in Middle Cretaceous time followed by East West fault pattern which active in Upper Cretaceous time where the hydrocarbons were trapped. Most of the older faults were facing towards North East and the younger faults were facing towards North West forming structural traps where our hydrocarbon was. The JK field formation tops the three layers were picked based on well petrophysical logs maps were prepared. The results of this part of the study show that the inter-bedded sandstones with shale of the three formation were meandering channel of delta system. Shaly units of the three formations interpreted as potential seals and were of variable thickness and extend. The reservoir was the braided-stream sandstones of Bentiu Formation, and the top seal was the fluvial shale of Aradeiba Formation. Most of the traps were normal fault blocks with high dependency on the lateral seal across the faults. Therefore, the above perfect sitting of source, reservoir, and top seal was associated with a higher risk in the lateral seal.
Seismic interpretation of the area shows that the three main seismic facies were dominant which mainly represent the recent sediments of the three Formations, underlying basement respectively. Some distributary eroded channel fill structures were also observed within the Bentiu Formation, but they were not continuous through the area because of the faulting. These gave a reasonable explanation for the hydrocarbon distribution in the area of study and explain why in some drilled wells there was no hydrocarbon shows.
AAPG Search and Discovery Article #90162©2013 Pacific Section AAPG, SPE and SEPM Joint Technical Conference, Monterey, California, April 19-25, 2013