Abstract
In multilayered reservoirs, major focus has been on the usage of smart well completion technologies to help improve recoveries, particularly with technological improvements and an increasing expanse of opportunities in more challenging and rewarding assets. The fundamental focus has been to design well completions that integrate several surface/subsurface sub zones and automate the flow control from each zone. In Multi zone Smart Completion Wells where significant investment is made to complete smart wells with remotely controlled inflow control valves (ICV), reservoir sweep & drain accessibilities becomes decisive when evaluating the efficiency of recovery and long-term field development strategy.
Smart completion designs for multi-lateral wells present many challenges in terms of completion deployment and interventions in life of well. The complexity of operations increases with deviation, type of completion equipment, number of zones and planned interventions.
In offshore, UAE a similar multilateral well was designed to be completed with 4 zone smart completion and had a mandatory requirement of accessibility to lower most drain (for future interventions) with the ability to plug the lower drain till future requirements arises. A solution is to utilize nipple & blanking plug in lower most drain, which was implemented in this well. Upon successful deployment of completion, plug was retrieved on coil tubing and lower drain accessibility was confirmed. However, during re-installation of blanking plug on coil tubing in deviated section, issues were encountered to pass through the ICV profiles. In attempts to pass through ICV profiles, blanking plug and running tool got disconnected from coil tubing, leaving the fish inside one of ICV valve. Several attempts were made to retrieve the blanking plug with rig on coil tubing without success by using thru-tubing fishing equipment options available in country.
Well was suspend to work-out fishing strategy & evaluate availability of fishing equipment worldwide. Consideration was done for design and manufacture application specific fishing tools to perform workover with barge for such smart completion, as it includes a number of downhole components that makes its retrieval more challenging, and there are no standard procedure or provision in place to retrieve such complex completions in highly deviated section.
A barge was mobilized with coil tubing, which performed the fishing operation as planned. Careful selection of equipment's, BHA and operational parameters resulted in successful retrieval of blanking plug & running tools. Accessibility to well was gain and confirmed.
This paper presents the situation that was faced, the remedial work done to complete well, fishing operations and the subsequent factors considered for choice of equipment and operation on well. This paper concludes a detailed account of factors to consider for planning smart completions in horizontal multilateral wells & the successful fishing operation – an excellent example of how careful planning, dedicated project management, specialized design fishing tools, experienced personnel and a collaborative relationship between team's leads to a successful operation and prevented an extremely expensive workover of a high technology completion well.