oa Charge evaluation of the South Rub’ Al-Khali Basin, Saudi Arabia (Part I, for Part II see Nederlof et al.)

The South Rub’ Al-Khali Company (SRAK) is exploring for gas and condensate in two contract areas which together encompass an area of approximately 200,000 square km. In order to quickly identify the most prospective areas in this large, yet relatively under-explored area, it was necessary in the first years of the venture to quantify the risk of source rock presence, the degree of maturation and predict the hydrocarbon mixture generated upon reaching maturity. Therefore, the regional geology of the Silurian-aged Qusaiba Formation was reviewed and the kinetic behaviour of the organic-rich shale was investigated in order to predict the likely phase of any hydrocarbon accumulation as well as the variations of condensate-to-gas ratios across the entire basin. The initial basin model identified the most prospective parts of the basin, and as more seismic data became available, the model was constantly updated. The kinetic behaviour of the Qusaiba Shales was measured using kerogen isolated from immature outcrop samples. Prior to the drilling of the first exploration well in 2006, predictions were made on the presence of source rock at the well location, its quality and the degree of maturation. This presentation will compare the outcome of the modeling with the actual well result, and is complimented by Part II (see Nederlof et al.)