A review of closed-in wells in the Northern Swamp Area (NSA) of The Shell Petroleum Development Company of Nigeria Ltd (SPDC) in 2003 revealed huge opportunities in closed in wells that can be realised at relatively low costs through the application of new technologies. Initial estimates of these opportunities in the Northern Swamp Area (NSA) were about 174 intervals with potential gains of some 53 Mbopd (unrisked) and costs of circa $27 million. A detailed review of these notional candidates was carried out by a multi-disciplinary team. The technically feasible and economically viable rigless (non-rig related) opportunities were matured for execution in 2004. This paper presents results of the rigless activities matured and executed in 2004.

From December 2003 to November 2004, 67 jobs were executed with actual total gains in potential of 44,889 bopd against 34,869 bopd planned. Annual average gains of 20Mbopd were realized from these activities against a plan of 14Mbopd. The jobs were executed at F$13.6 million, and Unit Technical Cost (UTC) of $2.07 per barrel. This project has a Net Present Value (NPV) of F$112 million.

A number of new technologies and cost savings initiatives were implemented during the execution of these activities.


The NSA team in SPDC has 211 oil wells (372 strings) drilled and completed as at 01/03/2003. A total of 258 strings were closed-in as at 01/03/2003. These strings were closed-in for various reasons: flowline problems, high gas production, low productivity, mechanical reasons, sand, water, wax etc. A review of the closed in conduits in Q2 2003 revealed that there are huge opportunities in closed in conduits that can be realised in short to medium term with application of new technologies at relatively low costs. Initial estimates of opportunities in NSA were about 174 intervals with potential gains of circa 53 Mbopd (unrisked) and costs of circa $27 million. These notional initial estimates of opportunities were reviewed and challenged by a multi-disciplinary team of petroleum engineers to confirm the robustness of the identified opportunities.

The objectives of the challenge sessions were to

  • Review scope of work and assess the do-ability of the identified opportunities;

  • Confirm the estimated potential oil gains of the identified opportunities;

  • Carry out reliable cost estimates of the activities required to realise the opportunities.

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