Follow us:

Youtube Twitter Facebook Google Plus


Home | Tests & Publications


SPE 26042

Prudhoe Bay Rig Workovers: Best Practices for Minimizing

Productivity Impairment and Formation Damage


C.G. Dyke, BP Exploration Operating Co. Ltd., and D.A. Crockett, ARCO Alaska Inc.


SPE Members


Copyright 1993, Society of Petroleum Engineers, Inc.


This paper was prepared for presentation at the Western Regional Meeting held in Anchorage, Alaska, U.S.A. • 26-28 May 1993.


This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented. Have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the Society of Petroleum Engineers, its officers or members. Papers presented at SPE meetings are subject to publication review by Editorial Committees of the Society of Petroleum Engineers. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Write Librarian, SPE, P.O. Box 833836, Richardson, TX 75083-3836, U.S.A. Telex, 163245 SPEUT.




A field wide review of rig workovers was carried out for the  Prudhoe Bay reservoir to enable a set of 'best practices' to be drawn  up and  implemented. Particular emphasis was placed on well  killing, together with  the minimisation of formation damage and  loss in productivity index associated with rig workover operations. Clear conclusions emerge which have a significant impact on productivity as well as reducing  total workover costs.


The results  of this case  history  are of direct  relevance   to all workover  operations,  detailing  how cost effective  well killing  can be performed   with  the minimal  productivity loss.




The  Prudhoe   Bay  field,  located  on  the North  Slope  of Alaska,  is  the  largest  reservoir   in the USA  with  initial reserves  of approximately 11 billion  barrels.  It is jointly operated by BP Exploration (Alaska) Inc. and Arco Alaska Inc. First production   was in 1977 and the field is now off plateau. Approximately 75 rig workovers are performed each year to maximize the steadily deteriorating well productivity.


To help minimize any avoidable productivity impairment and formation damage arising from these rig workovers, a field wide   review of past workover practice was performed. A wide  range  of  workover   strategies   have been  used  within  the  four  years  covered  by the review. These included  killing  with LCM,  living  with  losses,  as well  as  bullheading or  circulating the  well  during   the initial  kill. This variation  in past practice  enabled  a wide range  of well  killing  issues  to be addressed,   as  well  as assessing    the   extent   of  any productivity impairment associated with  previous   rig  workovers. Arising   from this, the review's objective - a set of best practices for future rig workovers,   was compiled.



Copyright © 2016 - All rights reserved.