Protecting the environment and health of the people by ensuring the integrity of all wells is one of the must-obey policies in Shell Petroleum Development Company of Nigeria Limited (SPDC). SPDC has been the leading producer of crude oil in Nigeria for more than 50 years. SPDC produces from many brown fields. SPDC currently has an inventory of producing wells that have been shut in because of one form or another of wellbore integrity problems. In some cases, these wells were completed decades ago when HSE requirements were considerably less stringent than they are today and wells were completed without sub-surface or downhole safety valves.

In 2003, a more stringent policy on non-integrity wells was introduced and led to an investigation of service providers for a more reliable rigless installation of safety valves or a more cost effective rig workover. However, most of the brown fields that encompass these wells are predominantly located in the Niger Delta both in the shallow waters offshore and in land locations including swamp areas. Many of the wells are located on small-unmanned production jackets which do not have the structural integrity to support even an electric line unit let alone a workover rig. In addition the current geopolitical situation in the Niger Delta is such that bringing in any heavy-duty equipment can be extremely difficult and highly uneconomical in most of these low producing wells.

It was against this background that SPDC carried out a well integrity management campaign to examine the feasibility of some kind of economic intervention to bring these wells back onto production.

In this paper the authors will examine in detail the prevailing situation, present details of the alternative solutions that were considered and describe a highly economic campaign that was put in place to rehabilitate some 40 wells and make available some 30,000 bopd of oil production, all without the use of major workover equipment.

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