Intervention-Less Multi-Zone Lower Completion Tools – A Case Study

Abstract

Driven by ever increasing associated costs, the industry has long sought an enabling technology to expedite hydraulic fracture cycle times in high cost environments such as offshore. Remotely operated completion tools have been proven to provide these efficiencies and can positively influence the viability of these multi-zone stimulation projects.

This paper will focus on the planning and execution of a recently completed offshore North Sea lower completion to present a methodology to remotely access and isolate the reservoir during multi-zone stimulation operations. Innovative technologies utilized in this case study are presented which effectively minimize the cycle time of the stimulation process while providing a high level of contingencies to account for a panoply of scenarios which could occur through-out the operation.

There are several techniques and methodologies which have been deployed to efficiently stimulate multi-zone, horizontal wells in offshore locations such as those found in the North Sea; technical papers such as (Langford 2014) discuss these in detail. This paper will describe the successful deployment of a novel lower completion system into a Southern North Sea extended reach well in June 2015 which targeted the a sandstone formation of the Lower Permian (Rotliegend) strata.

The selected remotely operated lower completion system incorporates multiple communication methods on-board to permit remote functioning of flapper isolation valves, to compartmentalize the reservoir internally, and remote operated stimulation sleeves to access the reservoir, which effectively eliminates the need for intervention between treatments, ultimately improving fracture cycle time and reducing risk while providing operators with realistic contingencies in the event of screen-out.