Utilizing UBD Technology for Future Development of Parsi Oilfield, Challenges and Opportunities Conference Paper uri icon


  • Abstract Underbalanced drilling is considered as one of the main recommended technologies for further development of Iranian depleted fractured carbonate reservoirs. Parsi is one of the most depleted oil fields located in south western part of Iran which started to produce with initial pressure of 3,800 psia in 1966. In 2001 the reservoir pressure was 3,000 psia with 1.48 Billion STB cumulative production. By June 2009 some1.68 Billion STB had been produced with the current reservoir pressure of 2,470 psia at 1,800 meters subsea. The serious challenge in this field is dealing with the complete losses in drilling operation. Also high production rate has increased GOR and caused gas coning. National Iranian Oil Company (NIOC) has initiated UBD technology program since 2005 in southern Iranian depleted fields. The key aspects for utilizing UBD in Parsi oilfield have been: avoiding complete losses and reservoir impairment, improving rate of penetration (ROP), drilling performance and reservoir fracture productivity. This paper evaluates the advantages of UBD in Parsi oilfield and summarizes practical solutions not only to overcome the challenges happened during the UBD implementation but also to gain more financial returns in drilling a well in this field. Data and experiences of OBD and UBD wells in Parsi field have been used as a basis for this study.

name of conference

  • All Days

published proceedings

  • All Days

author list (cited authors)

  • shadravan, A., Nabaei, M., & Amani, M.

citation count

  • 6

complete list of authors

  • shadravan, Arash||Nabaei, Mohammad||Amani, Mahmood

publication date

  • January 2009