Underbalanced drilling in depleted formation achieves great success: Case study

Arash Shadravan, Mohammad Khodadadian, Abbas Roohi, Mahmood Amani

Research output: Chapter in Book/Report/Conference proceedingConference contribution

9 Citations (Scopus)

Abstract

The PR-70 well, the third well of the National Iranian Drilling Company (NIDC) UBD campaign in Parsi field, is the first well to produce while drilling in a 2-year underbalanced drilling (UBD) project in the field. NIDC and Weatherford selected the UBD technique because of the depleted reservoir pressure, which had dropped to 2,728 psi at depth of 2,755m (5.8 ppg). Drilling such a depleted reservoir with conventional mud would have caused a huge overbalanced state, loss of circulation, and increased possibility of blowouts or damage to the reservoir. Another reason for implementing the UBD technique was to increase productivity of the well by decreasing formation damage that resulted from drilling fluid losses.This paper explains the execution of UBD technique at well PR-70. It also discusses the well design, UBD design parameters, underbalanced modeling considerations and the lessons learned from this job that all led to the success of this project. As soon as the well started to produce oil, UBD conditions were established and continued to TD.

Original languageEnglish
Title of host publication71st European Association of Geoscientists and Engineers Conference and Exhibition 2009: Balancing Global Resources. Incorporating SPE EUROPEC 2009
PublisherSociety of Petroleum Engineers
Pages3803-3808
Number of pages6
Volume6
ISBN (Print)9781615672363
Publication statusPublished - 2009
Externally publishedYes
Event71st European Association of Geoscientists and Engineers Conference and Exhibition 2009 - Amsterdam
Duration: 8 Jun 200911 Jun 2009

Other

Other71st European Association of Geoscientists and Engineers Conference and Exhibition 2009
CityAmsterdam
Period8/6/0911/6/09

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ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geotechnical Engineering and Engineering Geology

Cite this

Shadravan, A., Khodadadian, M., Roohi, A., & Amani, M. (2009). Underbalanced drilling in depleted formation achieves great success: Case study. In 71st European Association of Geoscientists and Engineers Conference and Exhibition 2009: Balancing Global Resources. Incorporating SPE EUROPEC 2009 (Vol. 6, pp. 3803-3808). Society of Petroleum Engineers.