Published: 01/21/2011
Published: 01/21/2011
An operator offshore India planned to complete a multizone well with either sliding sleeves or surface-controlled flow control equipment. For this triple-zone completion design, however, the sliding sleeves would have required intervention to shift, and the number of surface control lines needed for the flow control equipment outnumbered the available penetrations in the existing wellhead equipment. The need to eliminate interventions and use the existing equipment made the sliding sleeves and traditional flow control completions impossible.
To bring the well online, the zones required acid stimulation. With the sliding sleeve design, the operator would have needed to acidize all the zones simultaneously or deploy coiled tubing to manipulate the individual sleeves in each zone. Deploying coiled tubing would have added 3 weeks to the schedule, rendering this option impractical and too costly to pursue. Applying the acid treatment to all the zones at once would have unevenly treated only the most permeable zone, leaving the other two zones untreated. On the other hand, selecting one zone at a time would ensure that every zone was properly treated.
To meet the original design criterion of using the existing wellhead equipment, Schlumberger recommended using a modular intelligent completion, which comprises a flow control valve, an optional pressure and temperature monitoring system with valve position sensing, an optional multidrop module, and a packer. The multidrop module allows more flow control valves to be actuated on fewer hydraulic control lines than with traditional flow control completions and to be controlled from the surface in real time without intervention.
Use of the Schlumberger modular multizonal completion system instead of sliding sleeves or a traditional flow control completion enabled the operator to meet its critical design objectives. The multidrop capability eliminated three of the four control lines required with a traditional flow control completion, yet provided selective control of all three zones, allowing for the most effective acid treatment. The system also eliminated the need for the rig and coiled-tubing intervention, saving a total of 3 weeks. As a result, the operator optimized production at 165% of the originally expected rate and saved USD 1 million within the first 2 months.
Challenge: Eliminate time-consuming interventions required in typical multizone completions, retain independent control of three zones, and use already purchased wellhead equipment
Solution: Deploy a modular intelligent well completion, using a single hydraulic control line for three zones and the existing wellhead equipment
Results: Selectively stimulated zones, avoided interventions, optimized production at 165% of the originally expected rate, and saved USD 1 million within the first 2 months
