| Popis: |
In this paper, attempts have been made to describe the experiences of 1.5 months of Managed Pressure Drilling (MPD) operations conducted in hard rock Formation in Rub Al-Khali, Eastern province of Saudi Arabia. The implementation of this technology arose from the lessons learnt from previously drilled 2 exploratory wells that penetrated the tight gas sandstone Formations of Sarah and Qasim at a depth exceeding 17,000 ft, where the temperature and stress are extremely high at 350°F and 1.0 psi/ft respectively. As a result of these conditions, it is necessary in all cases to perform hydraulic fracturing to define fluid characteristics and evaluate production potential. The extreme low porosity range of 2-10 % coupled with low permeability range of 0.01 – 0.26 mD and high fracture gradient interval of 0.9 – 1.0 psi/ft are the main challenges on these wells. Moreover, other challenges faced include drilling with high overbalance mud weight across the reservoir and high abbresivity of the formation rocks resulting in difficulty identifying potential gas bearing sands and slow drilling rate respectively. As a part of the referenced exploratory activity in the 3rd quarter of 2008, LUKSAR was challenged to drill across the target reservoir with minimum formation damaged, balance mud weight and swift reaction in identifying suitable coring interval. Hence, in response to these challenges, an extensive study and well design/engineering were carried out in order to accommodate the utilization of Managed Pressure Drilling (MPD) across Sarah-Qasim sandstone Formation on wells LUK-08 and LUK-09. This paper summarizes the well operation and in particular lessons learned during the first field application of Managed Pressure Drilling (MPD) in LUKSAR Exploration Campaign that resulted in significant improvement in well deliverability compared to previously drilled wells in Sarah-Qasim structure. |
