Sand Control Screen Construction Types

Sand control well screens are manufactured in three main construction types, each engineered for a different combination of mechanical loading, formation behavior, and completion design. Selecting the wrong type leads to premature failure -- either by screen collapse, sand production, or plugging.

Direct-wrap (wire-wrapped on rods)

V-wire is helically wound around an inner array of longitudinal support rods and resistance-welded at each crossing point. There is no inner pipe; the welded rod cage carries the mechanical load. This produces the highest open area of the three types, typically 35 to 65 percent depending on slot aperture and wire profile. The light weight and high inflow capacity make direct-wrap the preferred choice for monitoring wells, observation wells, low-pressure dewatering screens, and shallow water wells where formation pressure and axial load are moderate. Direct-wrap is also used as the outer element in pre-packed configurations.

Pipe-based (perforated base pipe with wire wrap)

A perforated API base pipe (with drilled holes or machined slots) forms the structural backbone. V-wire is wound and welded over the outer surface, separated from the pipe by support ribs that maintain a clear annulus for inflow. The base pipe provides axial tensile strength, collapse resistance, and reliable threaded end connections (BTC, NUE, EUE, or premium threads), making this the standard construction for vertical and horizontal hydrocarbon production wells. Open area is lower than direct-wrap (typically 5 to 15 percent of the base pipe surface, set by the perforation pattern), but the screen can be run on tubing through deep, deviated wells without buckling. Pipe-based screens are the workhorse of API 19SS sand control completions.

Pre-packed gravel screens

Two concentric wire-wrapped screens enclose a layer of resin-bonded or loose gravel between them. The inner gravel layer is sized to bridge formation sand grains and acts as a primary filtration medium; the outer and inner screens retain the gravel pack itself. Pre-packed screens deliver the highest level of sand control in unconsolidated formations and open-hole completions where conventional gravel-packing operations are impractical. The gravel size is sized against the formation D50: gravel D50 is typically 5 to 7 times the formation D50, then the outer screen slot is sized to retain the gravel rather than the formation directly. Pre-packed screens carry a cost and complexity premium and reduce open area further, but they prevent fines migration and screen erosion in poorly consolidated reservoirs.

Selection summary

Use direct-wrap when formation pressure and axial load are moderate, open area is the primary design driver, and an inner pipe is not required. Typical applications: monitoring wells, observation wells, dewatering, shallow water wells.

Use pipe-based when the screen must handle the axial and collapse loads of a deep, deviated, or high-pressure production well. The perforated base pipe also enables reliable API thread connections and provides a positive seal against the well casing during gravel-pack operations. This is the standard choice for vertical and horizontal oil, gas, and water injection wells.

Use pre-packed gravel when the formation is unconsolidated or fine-grained, conventional gravel-packing is not feasible, and additional sand control beyond a slot-only screen is required. Common in heavy oil, SAGD, and certain offshore unconsolidated sandstone reservoirs.

Manufacturing notes

ADEN manufactures all three construction types from material grades ranging from SS 304L through Super Duplex 2507, Inconel 625, and Inconel 825 for corrosive or sour service. End connections include API tubing threads (BTC, NUE, EUE, premium), API flanges, and plain ends. Screens are tested per API 19SS / ISO 17824 requirements including axial load, collapse pressure, and burst pressure on selected samples per lot.