Sand management is a reality in life-of-well planning. Standalone screens commonly are used to mitigate problems associated with fines migration, which can damage surface equipment and result in a rapid decline of production for an otherwise decent well. Gravel packing can assure a clean annular flow where the well bore has eroded in friable zones, but this requires expensive pumping capacity and sometimes more than several trips to provide ample protection from solids intrusion. Expandable screens have seen several innovations in recent years, but even these have limitations in openhole applications.

What if a material existed that could provide full conformance with the sand face in just one trip? That question may soon be answered. Shape memory polymer (SMP) technology is not a new science. Open-cell foams have been looked at for oil and gas applications since 1990. It is only recently, however, that these industries have found a common ground on which to interact.

Early this year, Baker Hughes Inc. announced its Geo Form Sand Management System, which uses SMPs to construct downhole production strings that meet the sand face, provide ample porosity, and guard against fines migration for possibly 10 years or more.

The concept relies on specialized polymers that are molded and milled to a desired shape and size. Baker Hughes has on offer two current sizes. The 2 7/8-in. by 6-in. screen has a fully compacted OD of 4.6 in. Once activated, the screen expands to 7.16 in., which is recommended for 6-in. to 6 1/4-in. openhole completions. The 5½-in. by 8½-in. screen fully compacts to 7.125 in. with an expanded OD of 9.390 in. and is designed for 8/8-in. to 8?-in. hole. Both screens are designed to operate between 105?F to 195?F (40.5?C to 90.5?C), although the company is researching methods to expand this to a higher range.

According to Baker Hughes, these new screens are ideal for gravel pack replacement, long horizontal wells, slimhole applications, and remedial sand control. In their compacted state, the screens have proven to withstand scarring in drill tests of up to 4,000 ft(1,219 m) of lateral movement at 30 rpm.

This “smart” material is activated downhole through exposure to bottomhole temperatures and specialized catalysts to unlock the compacted screens once in place, allowing the SMP to return to its original shape, conforming to the annulus of the well bore and filling in any irregularities as it expands. An interesting feature to these new screens is the material’s replication of pore space. Whereas porosity is devised from the space between the solid particles within a reservoir, the shape memory material provides an inverse of this matrix with its pore space in closer relation to actual grain size. Also, it is designed with a 10:1 ratio of radial to axial permeability to prevent solids migration to the well bore. Fully expanded screens using memory SMPs provide about 80% porosity; even at full compaction the screen maintains 10% porosity.

So what is the bottom line? According to information provided by Baker Hughes, gravel packs have a historical transactional failure rate of 16%, which translates to more than five hours of nonproductive time (NPT) per tool per well. In its current tests, Baker Hughes Geo Form screens have shown a transactional failure rate of less than 4%, with an NPT of less than one hour per tool per well. Overall, this new technology could net operators a 75% reduction in NPT and associated costs (roughly US $100,000 per well) within this segment of the completions process.

As with any new technologyentering the market, it will be interesting to see how these tools perform in the field and if they will gain acceptance over time.