E-LINE PRODUCTION TUBING AND SSSV CLEAN-OUT SAVES ONE WEEK

Well Cleaner for Clean-out solutions

Background

Careful planning combined with experience were the decisive factors behind a recent success offshore Mexico. An operator in the Marine Region needed to set a pressure and temperature sensor in two wells. To be able to collect the accurate data, the client had to install a downhole pressure sensor in each well with slickline. In one of these wells the subsurface safety valve (SSSV) was not hermetic and the production tubing had a restriction, which prevented slickline from reaching setting depth with the pressure sensor. Production tubing clean-out is typically a coiled tubing (CT) operation, but for this operation CT would take at least a week due to the lack of fluid and stimulation vessels. Welltec’s nimble clean-out solution therefore represented a much lighter alternative. The strategy was thus to perform a production tubing clean-out and with the same e-line robotic tools perform the SSSV clean-out.

OPERATION

Before the operation the tools were thoroughly prepared and tested at the well site and a gauge run was performed to confirm exact location of the restriction. Welltec® mobilized a wide range of tools and accessories to offer the client a variety of solutions on site. First the Well Miller® with 3.5″-3.75″ bits cleaned from surface through 8,520 ft (2,660 m). Two scale bridges were encountered and efficiently removed from 174 to 335 ft and from 531 to 538 ft (53-102/162–164 m). After the successful production tubing operation the Well Cleaner® WBH was run in hole to clean the SSSV.

Because the valve was not sealing properly the hydraulic pressure was reduced from 2700 psi and 1000 psi to 1900 psi and 900 psi, which enabled the SSSV to open and close more easily. The successful operation enabled the operator to set a downhole pressure sensor with a 2.5″ OD that, in conjunction with the other two wells, will help to measure pressure and perform a reservoir analysis.

ACHIEVEMENTS

Welltec met both objectives with one mobilization and dramatically reduced operation times by performing both interventions in 72 hours – including rig up and rig down. Using CT would have added at least one week to the operation as well as more personnel. Also, Welltec’s e-line solution eliminated the need to mobilize a stimulation vessel, fluids like acid, diesel and solvents as well as the CT unit itself.

This freed up the CT unit for other work. Furtermore, Welltec’s e-line tools increased the flow area by 50% due to the 3.5” bit used for the Well Miller versus the 2.625” bit for the CT program. The operator had previously used the Well Cleaner WBH with great results, but is now confident that Welltec also offers effective solutions for scale removal.

WELL TYPE: PRODUCER WELL
(BUT NOT IN PRODUCTION DURING OPERATION)
MAX. DEVIATION: 20.5°
PRESSURE: 0 PSI
MAX. TEMPERATURE: 277°F AT 12,260 FT
(136°C AT 3,737 M)

 

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Welltec met both objectives with one mobilization and dramatically reduced operation times by performing both interventions in 72 hours – including rig up and rig down.