Print this pageAAPG GEO 2010 Middle East
Geoscience Conference & Exhibition
Innovative Geoscience Solutions – Meeting Hydrocarbon Demand in Changing Times
March 7-10, 2010 – Manama, Bahrain
Multi-Tool Approach to Well Placement in a Heavy Oil Column of the Manifa Field - A Case Study
(1) Reservoir characterization, Saudi Aramco, Dhahran, Saudi Arabia.
Manifa field is located north of the giant Ghawar field in the Eastern Province of Saudi Arabia. The field is currently under development with more than 300 wells planned for drilling in two major reservoirs, the Manifa (Upper Jurassic) and the Lower Ratawi (Lower Cretaceous). An approximately 30 to 40 feet thick column of heavy oil exists in both of these reservoirs. The well test records indicate that the oil quality degrades towards the flanks of the structure causing complexities in wells placement, especially for power water injector (PWI) wells. A multi-tool approach has been applied to address the challenge of placing the PWI wells to achieve the targeted water injection rates.
The successful approach to optimally placing PWI wells combines the use in real time of: a) formation pressure while drilling (FPWD) for measuring formation pressure and fluid mobility, b) slim-hole nuclear magnetic resonance (NMR) for providing the free and bound fluid volumes as input to a viscosity model, c) pyrolytic oil productivity index (POPI) for computing apparent API gravity of the oil, and d) logging while drilling (LWD) for calculating parameters such as permeability.
Using this multi-tool approach, a significant number of PWI wells have been drilled and geosteered through sections with a heavy oil column. To date, the injectivity test results of both short and long term duration have been encouraging.