Petroleum Systems Analysis and Lithologic Traps Identification in Rifted Basin Based on Accommodation Space and Sediments Supply: A Case on Abu Gabra Formation in Block 1/2/4 of Sudan, Muglad Basin

Abstract

Finding oil and gas in lithologic traps is still a big challenge in faulted basin, with multi‐periods tectonic subsidence, complicated fault systems and provenance supply variations, and petroleum system analysis is the necessary way to locate favorable lithology targets. Based on the theory of dynamic balance between accommodation space and sediments supply in high‐resolution sequence stratigraphy, hydrodynamic analysis of sedimentary facies (i.e., fan delta, braided delta, delta front and turbidite) sands were identified. Compared with multiple seismic attributes, RMS can be an effective way to indicate sands distribution and evolution. Based on paleotopography restoration results, source rock evaluation (TOC, HI, Ro and Tmax), reservoir sands evaluation (favorable sands distribution and porosity) and cap rock evaluation (shale thickness) of Neem‐Azraq area, northeast development zones in block1/2/4 were done. (1) Source rock in AG2 and AG3 members were favorable in AG formation of high TOC and mature, most in oil generation phrase with II1‐II2 type. (2) subaqueous distributary channels and turbidite sands were favorable for lithology traps of relatively high sand/bed ratio, slope belt in paleotopography restoration, with 10‐40% neutron porosity. (3) 100‐400m gross shale thickness from AG4 to AG2 member were favorable cap rock. Multiple periods of faults growth had a good relationship with oil ‐ gas mature, migration and preservation, and finally 10 lithologic traps of AG formation were identified with near three billion tons of oil‐gas resource increase.

AAPG Datapages/Search and Discovery Article #90349 © 2019 AAPG Hedberg Conference, The Evolution of Petroleum Systems Analysis: Changing of the Guard from Late Mature Experts to Peak Generating Staff, Houston, Texas, March 4-6, 2019