Corrosion Inhibition of Carbon Steel in a Sour (H₂S) Environment by an Acryloyl-Based Polymer

Abstract

Corrosion poses safety and operational challenges in the oil and gas field, particularly in a sour environment. Corrosion inhibitors (CIs) are thus employed to protect the integrity of industrial assets. However, CIs have the potential to dramatically impair the effectiveness of other co-additives, such as kinetic hydrate inhibitors (KHIs). Here, we propose an acryloyl-based copolymer, previously used as a KHI, as an effective CI. The copolymer formulation provided a corrosion inhibition efficiency of up to 90% in a gas production environment, implying that it can reduce or even eliminate the need for an additional dedicated CI in the system. It also demonstrated a corrosion inhibition efficiency of up to 60% under field-simulated conditions for a wet sour crude processing environment. Molecular modeling suggests that the enhanced corrosion protection is imparted by the favorable interaction of the heteroatoms of the copolymer with the steel surface, potentially displacing adhered water molecules. All in all, we show that an acryloyl-based copolymer with dual functionalities can potentially overcome issues caused by incompatibilities in a sour environment, resulting in significant cost savings and operational ease.

Study of the Electrochemical Behavior of Concrete‐Coated Steel in 1 M Sulfuric Acid Using an Extract of Diplotaxis simplex L.

“…However, when the third and fourth concentrations (200 ppm and 300 ppm) are introduced, the OCP experiences a decline towards more cathodic values before stabilizing at −425 mV. This distinctive pattern suggests that the incorporation of DS induces alterations in the corrosion rate over time, attributed to the adsorption of DS molecules onto the metal surface [1,29] …”

“…This distinctive pattern suggests that the incorporation of DS induces alterations in the corrosion rate over time, attributed to the adsorption of DS molecules onto the metal surface. [1,29] Tafel polarization studies Figure 3 presents potentiodynamic polarization curves for concrete specimens exposed to a 1 M sulfuric acid solution, both in the absence and presence of D. simplex (DS) at varying concentrations (50 ppm, 100 ppm, 200 ppm, and 300 ppm). These experiments were conducted at room temperature.…”

Highly Biodegradable Corrosion Inhibitors Derived from Sunflower Oil for Mild Steel Corrosion in CO2- and H2S-Saturated Oilfield-Produced Water

“…Some inhibitors can neutralize acidic components present in the sour gas, reducing the overall corrosivity of the environment . Sour corrosion inhibitors can be broadly categorized into four main groups: water-based polymers, gemini surfactants, imidazolines, and amines. ,− Among these, amines and imidazoline dominate the market share, serving as the primary chemistry basis for sour and sweet inhibitors. , Tributylamine, diphenylamine, cyclohexylamine, dibutylamine, phenylenediamine, and N-substituted polyamines are well-known inhibitors for sour media. ,, Imidazolines and their derivatives demonstrate remarkable efficacy as corrosion inhibitors . Imidazoline-based formulations, including Marcor 310, 550, 900, and Ps9, are the predominant inhibitors found in commercial products designed for oilfield applications.…”

Multi-functional Flow Assurance Chemicals: Corrosion and Kinetic Hydrate Inhibition from Maleic Anhydride:N-Vinyl Caprolactam Copolymers and Synergists

“…Examples of SI–CIs include polyaspartates, and examples of KHI–SIs are polyaspartamides. Examples of KHI–CIs include N -vinyl lactam copolymers, N -alkylacrylamide copolymers, and polyurethanes. − The subject has been recently reviewed. A pioneering study by Sheng et al, and inspirational to our own studies, investigated the use of VCap copolymers as KHIs and CIs (Figure ).…”