A review of hydraulic work-over unit (HWU) application for well repairs in Nigeria
Date
2014
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
U. P.
Abstract
As part of efforts to encourage indigenous/local content in the area of work-over, re-completion and abandonment in Nigeria, Work over campaigns using a self elevating work-over platform (SEWOP) and a hydraulic work-over (HWU) unit was introduced in the year 2001. These projects provided an opportunity for Nigerian indigenous contractors to work closely with multinational companies with a view to develop expertise. Upon this platform was the services of the HWU introduced to the Nigerian oil & gas industry (for work-over, re-completion, well testing and abandonment) introduced to the Nigerian oil & gas industry. The initial objective of these campaigns was to equip older wells in the land and swamp locations with Surface Control Sub-surface Safety Valves (SCSSV) and top packers, in accordance with company’s well integrity management policy. This policy also required that some of these wells be abandoned to ensure the safety of the environment. It also presented an opportunity to carry out other well repairs and to install gas lift mandrels as the case may be. The projects’ priority factor (if compared with other income generating projects within the system) was low, especially for the abandonments. Hence, recognizing that funds are limited, the services of the HWU provided versatility and cost effectiveness .Between August 2001 and March 2006, a total of about fifty three wells were successfully worked on across the Niger Delta region in land, swamp and offshore locations. These series of operations were not without challenges considering the peculiar nature of the Niger Delta terrain in terms of operation and service delivery. Within the period mentioned above, a “learning curve” was developed for hydraulic workover that can be useful to operators in the oil and gas industry. In this paper, efforts have been made to describe this “curve” for the purposes of improving business results. This paper will also review significant cost saving achievements and challenges that were encountered during the entire period under review.
Description
The article contains tables and figures
Keywords
Workover, abandonments, well integrity, HWU, marginal fields, completion, Department of Petroleum Engineering, well repairs
Citation
Ohia, N., Anayadiegwu, C. & Igwilo, K. (2014). A review of hydraulic work-over unit (HWU) application for well repairs in Nigeria. Petroleum & Coal (56)4, xxx-331