Sand Control Materials: Sweet vs Sour
Sweet, sour, or severe: well chemistry determines sand control screen service life. This guide maps each downhole environment to the right alloy grade.
Published by ADEN Wedge Wire Engineering Team · Last updated May 3, 2026
Sand control well screens operate in chemically aggressive environments. Material selection is the single biggest factor in service life: a screen in the wrong material can fail within months, while the same screen in the correct grade lasts the full 15- to 25-year well lifecycle. Selection starts with the well chemistry profile.
Sweet service (CO2, brine, no H2S)
Sweet wells produce hydrocarbons with carbon dioxide and chloride but no significant H2S content. CO2 forms carbonic acid in the presence of water, causing general corrosion that responds well to corrosion-resistant alloys.
SS 316L baseline: low-chloride sweet wells, low-temperature operation, no significant CO2 partial pressure. Cost-effective and widely available.
Duplex 2205 for elevated chloride: produced water chloride content above approximately 1000 ppm, or where intermittent chloride spikes occur during workovers and well stimulation. Duplex 2205 offers approximately double the yield strength of 316L (around 450 MPa) and a chloride tolerance up to roughly 3600 ppm at typical reservoir temperatures.
Sour service (H2S present)
Sour wells produce H2S in addition to or instead of CO2. H2S exposure can cause sulfide stress cracking (SSC) in standard steels, requiring materials qualified under NACE MR0175 / ISO 15156. This standard limits material hardness, restricts certain alloying elements, and specifies environmental exposure limits.
Duplex 2205 (NACE-compliant): the standard sand control material for moderate sour service. Resists SSC up to defined H2S partial pressures, chloride concentrations, and temperatures specified in the NACE envelope.
Super Duplex 2507: severe sour service, higher H2S partial pressure, higher chloride, higher temperature. PREN > 40 provides extended pitting resistance in produced water.
For wells outside the NACE MR0175 envelope for Duplex grades, nickel-based alloys become the standard choice (see severe service below).
Severe service (high temperature, sour + high chloride, acidizing)
Combinations of high H2S, high CO2, high chloride, and high temperature exceed the operating envelope of even Super Duplex. Steam injection (SAGD) wells, deep gas wells, and wells with high-strength acid stimulation fall into this category.
Inconel 625 (UNS N06625): nickel-chromium-molybdenum alloy with excellent resistance to chloride pitting, crevice corrosion, and SSC at high temperatures. Standard for sour gas wells operating above the Duplex envelope.
Inconel 825 (UNS N08825): nickel-iron-chromium with copper and molybdenum, optimized for resistance to sulfuric acid and sulfide-rich environments. Common in wells with high CO2 partial pressure.
Both grades carry a significant cost premium over Duplex (typically 3-5x). They are specified only when the well environment justifies the investment.
Selection summary
Sweet, mild (no H2S, chloride < 1000 ppm): SS 316L. Sweet, elevated (no H2S, chloride 1000-3000 ppm): Duplex 2205. Sour, moderate (within NACE envelope, chloride < 3600 ppm): Duplex 2205 (NACE-qualified). Sour, severe (high H2S partial pressure, high chloride): Super Duplex 2507. Severe combined (outside Duplex envelope, high temperature): Inconel 625 or Inconel 825.
NACE MR0175 documentation
For any sour-service application, ADEN provides material test reports (MTR) per EN 10204 Type 3.1, NACE MR0175 / ISO 15156 compliance certificates, and hardness verification reports on the welded screen body. Pickling and passivation is applied as standard after welding to restore the chromium oxide layer disturbed by resistance welding.
A material upgrade to the correct sour-service grade is far less expensive than a single screen failure in a producing well, which can lose months of production and require an expensive workover to replace.