Hydrocarbon discoveries in the fractured granitic and metamorphic basement rocks in Yemen and worldwide

Category Petroleum Geology
Group GSI.IR
Location International Geological Congress,oslo 2008
Author Nani, Abdul Sattar; Albanna, Khaled
Holding Date 07 October 2008

Many of the world’s proven oil reserves have been discovered in reservoir rocks that are naturally fractured (Waldren & Corrigan, 1985 ; Aguilera, 1995; Nelson, 2001). In his updated book, Nelson (2001 ) gives a list of some 370 fields where natural fractures are important for production and a significant proportion are in the basement settings. BP Amoco alone are estimated to account for some 21 billion barrels of oil.
In Yemen oil discoveries have been achieved in the Granitic and Metmorphic Fractured Basement. The oil fields are (Fig-2): 1- Sunah. 2- North Camal. 3- Kharir. 4- Wadi Tariba. 5- Nabrajah. 6-S.W. Bayoot. All these fields are located in the Masila Basin.
In July-2005 OMV tested the well Habban-1, it gave 2500 BOPD from a granitic basement, in the Shabwa Sub-Basin. This is the first very encouraging result in Shabwa Sub-Basin, which will persuade the oil companies to study the fractured granitic and metamorphic basement.
It is very important to have a greater understanding of the fracture distribution and connectivity within basement reservoirs may prove to be the key tool for improved exploration and production management of this hidden resources.
What favourable conditions are required in Basement Rock Reservoirs: 1 - Basement Paleo-High, undergone for a long period of regional erosion. 2 - The younger sediments, which act as hydrocarbon sources like in Yemen Madbi or Lam shales Fm,to be either on the down thrown faulted flanks or directly overlie fractured basement providing the opportunity for the entrapment of oil in the Basement rock.