Well A is one of the only two wells on the XY reservoir structure providing the optimum drainage point on that reservoir. However, Well X had been shut in due to high sand production and had been flagged as ‘non-integral’ with regards to SPDC Well Integrity Management (WIM) policy due to its faulty Tubing Retrievable Surface Controlled Subsurface Safety Valve (TRSCSSSV). The well was thus scheduled for repairs. The objective of the workover operation as with most others done in SPDC was to restore integrity of the well, remediate sand control and improve production across the XY reservoir. On re-entry into the well, a mechanical restriction was met in the high angle section of the well thus impeding access to drain hole. A review of the situation, showed a possible collapse of the lower completions (sand screen) possibly due to high sand production. An attempt at sand clean-up was futile. This paper describes the unconventional but successful deployment of wireline conveyed perforation gun on tractor in SPDC to perforate this highly deviated well, thus, providing drainage access and recovering 2.14 MMstb of oil and 0.79 BScf of associated gas. Amongst several options including the use of coiled tubing or wireline as means of perforation, the tractor conveyed guns stood out for a highly inclined well such as Well A. The Well Tractor functions with an electric over hydraulic power relationship and uses its wheel section to push the passenger tool downhole as cable is fed off the electric line unit. The make-up of the tractor conveyed system makes it suitable for high angle wells while providing a cost savings over other systems.

Significant emphasis on data quality is placed on real-time drilling data for the optimization of drilling operations and on logging data for quality lithological and petrophysical description of a field. This is evidenced by huge sums spent on real time MWD/LWD tools, broadband services, wireline logging tools, etc. However, a lot more needs to be done to harness quality data for future workover and or abandonment operations where data being relied on is data that must have been entered decades ago and costs and time spent are critically linked to already known and certified information. In some cases, data relied on has been migrated across different data management platforms, during which relevant data might have been lost, mis-interpreted or mis-placed. Another common cause of wrong data is improperly documented well intervention operations which have been done in such a short time, that there is no pressure to document the operation properly. This leads to confusion over simple issues such as what depth a plug was set, or what junk was left in hole. The relative lack of emphasis on this type of data quality has led to high costs of workover and abandonment operations. In some cases, well control incidents and process safety incidents have arisen. This paper looks at over 20 workover operations carried out in a span of 10 years. An analysis is done on the wells’ original timeline of operation. The data management system is generally analyzed and a categorization of issues experienced during the workover operations is outlined. Bottlenecks in data management are defined and solutions currently being implemented to manage these problems are listed as recommended good practices.