A major global oil and gas producer1 has recently embarked on decommissioning of temporarily abandoned wells onshore, Nigeria. This was largely informed by a drive to ensure commitment to safeguarding of people and the environment and to ensure industry regulatory compliance/best practice. In addition in some cases human habitation has since encroached around these wells; most of which were drilled over 30years ago and have since outlived their useful life. 1 The decommissioning entailed total removal of both surface and sub-surface well equipment, installing permanent barriers to effectively isolate fresh water reservoirs from hydrocarbon bearing reservoirs in an environmentally safe manner, and subsequently restore the surface location, as close as possible, to its original state. Therefore, traditionally a conventional work-over rig would have been required. However, after an in-depth analysis –technical, economic and safety- the producer chose a combination of the Hydraulic Workover Unit (HWU) and the Casing Jack Dual Stage Work Platform (CJ-DSWP) over the conventional workover rig. The HWU3 and CJ-DSWP4 was provided by Tecon Oil Services, an indigenous services company. The HWU and CJ-DSWP are compact hydraulic units with very small foot print; HWU rigged up directly on the wellhead2, is used to POOH (pull out of hole) the tubing strings and to secure/plug the well, CJ-DSWP deploys internal pressure pipe cutter to cut the casing, safely pull the casing to surface and cut them to shorter lengths for easy handling. The combination of the HWU and CJ-DSWP has safely decommissioned over 4wells as at December 2013 and also brings a huge cost saving compared to conventional workover rig. This paper is a review of how the HWU and CJ-DSWP duo have been able to accomplish this. It highlights the advantages HWU-CJDSWP offered and as well as the challenges that were encountered.
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