Maximize cleanup and minimize sand production in unconsolidated sand and gravel-pack completions

The TRUST™ transient rapid underbalanced surge technique is a single-trip perforating and surge process used in unconsolidated sands. Specifically designed to achieve effective cased hole gravel-pack completions, the technique also provides efficient cleanup of perforation tunnels by removing perforation debris and crushed sands behind the casing.

• Downhole testing
• Shoot-and-pull tubing-conveyed perforating (TCP) operations
• TCP in unconsolidated sands
• Cased hole gravel-pack completions

• Reduced risk of sanding in the BHA
• Optional single- or multiple-trip performance based on well conditions and customer preference
• Enhanced well control from combining hydrostatic fluid and packer
• Loss monitoring and recording during string repositioning prior to surge operations
• Maximized cleanup and minimized sand production due to surge-chamber design
• Effective perforation methodology for unconsolidated sand and gravel-pack completions

Fast, effective perforation cleanup

At the core of the TRUST technique is a downhole atmospheric chamber equipped with either a single-shot annulus-pressure-activated pipe tester valve (PTV) or the IRDV™ intelligent remote dual valve at the top. Another IRDV dual valve is positioned at the bottom, just above the perforating gun string. Following guidelines derived from laboratory studies, specialists size the chamber volume to provide a set inflow per perforation.

High differential pressure localized around the perforations causes formation fluid to surge into the wellbore, effectively pushing out loose fines from the tunnels. These fines then settle at the bottom of the rathole. The design of the surge chamber is critical to the success of this technique and must be carefully executed to ensure thorough cleanup without causing formation collapse.

The standard TRUST technique assembly consists of

• HSD™ high shot density perforating gun system
• retrievable packer
• lower IRDV valve
• surge chamber
• PTV or upper IRDV valve.

An eFire™ electronic firing head or a stand-alone fast gauge can be run to record the dynamic underbalance during the surge.