Structural Style and Riftogenic Sedimentation Pattern of Muglad Basin, Sudan, Africa: A Sequence Stratigraphic Approach

Trivedi, K.B., Kamil Idris, Mustafa Eltayeb, Greater Nile Petroleum Operating Company, Khartoum, Sudan

The Muglad basin situated in southern Sudan owes its origin to breakup of Gondwana land which was synchronous with Intra-continental rifting within West and Central Africa during late Jurassic-Early Cretaceous times. The basin evolved in consequence of Sudanese rift which is a main component of West and Central African rift related system (WCARS). Accommodation created by these rifts recorded very thick sedimentation essentially during Cretaceous and Tertiary.

The concession under study falls in block four and is having low well density .All pene­trated sedimentary rocks ranging in age from early Cretaceous to Tertiary are of non-marine origin. The sediments clearly bear the signature of three distinct rift phases, each followed by a sag phase.

Based on Well, Seismic, Electrolog, Sedimentological and Biostrat. Data authors have applied a Sequence stratigraphic approach to understand spatio-temporal characteristics of accommodation development which has a major impact on stratal geometry and facies stacking pattern. By assimilation of G&G data three first order, six second order and nine third order cycles are being identified. The first, second and third “Third order cycles” cor­responding to Abugabra Fm. (Barremian-Neocomian), Lower Bentiu, and Upper Bentiu Fm. (Albian- Cenomanian) are further divided into fourth order cycles i.e. parasequences. The mapping of these chronounits in area has given a clear understanding for a depositional processes operated from time to time and shell lead to firming up exploratory locales. Components of two petroleum systems are also being identified in the area which will pro­vide an insight to understand the petroleum system and help in optimizing and prioritizing the future exploratory targets.