A Fail-Safe Sand Control Concept for High Rate Wells and the Stimulation of Unconsolidated Sands
Authors: Rike James L. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Wells with sand-producing problems are usually kept on production with screens, gravelpacked screens, sand consolidation with plastic, or resin-sand packs, according to plastic, or resin-sand packs, according to current technology.

Screens and gravel packs often result in mild to severe productivity loss, sometimes immediately after the gravel pack or screen is in place, or sometimes after varying cumulative amounts of production. Installations can be expensive in multiple completions, especially in directional offshore wells. When working in perforated pipe, a severe restriction results if perforated pipe, a severe restriction results if the perforation tunnel fills with formation sand or if fines in the formation sand invade the gravel placed in the perforation tunnels.

Sand consolidation methods reduce productivity in many wells treated. Success is highly dependent on the placement technique used and the unknown plugged or unplugged condition of the perforation plugged or unplugged condition of the perforation holes treated. Many wells treated remain rate limited. Failures of initially successful treatments are common with continued time and production. Failures occur without wanning and production. Failures occur without wanning and with potentially catastrophic results.

The resin-sand pack treatments suffer a greater disadvantage in the area of placement problems, since none of the particulate matter problems, since none of the particulate matter coated with resin can possibly travel across the vertical permeability within the sand. This precludes any opportunity to consolidate the precludes any opportunity to consolidate the sand mass behind some or all of the plugged perforations, as might happen in a straight perforations, as might happen in a straight resin consolidation process.

A new concept, which includes a specifically designed screen and quite large gravel placed with a prior treatment of consolidating plastic, promises to eliminate most disadvantages of promises to eliminate most disadvantages of currently used techniques. It is a fail-safe system by protecting against failure of the plastic in all or in part of the consolidated plastic in all or in part of the consolidated region. The process first introduces a resin material into the formation before the well is gravel-packed with large gravel. The resin consolidates the formation sand that remains in direct contact with the pack gravel after the job is complete. The use of large gravel maximizes productivity through-out the gravel-packed interval and especially in the perforation tunnels. Since the formation sand has been consolidated at the interface, the large pack gravel will not become invaded with the formation sand. The pack gravel need not be sized to bridge the formation sand, since the formation sand has been consolidated in the region where invasion would occur.