Preventing Scale Formation Using Modified Surfaces

摘要

A major challenge faced by the oil and gas industry is the minimization of scale formation within installations; new regulations are requiring conventional inhibitors to be replaced by green chemistries or green scale inhibition strategies which may involve anti-fouling surfaces. This paper focuses on the ability of different surfaces to reduce or modify calcium carbonate scale formation with the final objective being to understand what constitutes a surface that minimises the potential for scaling. Seven different surfaces have been tested (stainless steel, stainless steel pre-treated with Polyphosphinocarboxilic Acid (PPCA), Polytetrafluoroethylene (PTFE), Diamond-Like Carbon (DLC), ceramic and polymer coated stainless steels and an isotropic superfinished stainless steel surface). A subset of these surfaces was eroded within a Submerged Impinging Jet (SIJ) to assess the possible effect of in-service performance. The surfaces were first characterized by contact angle, roughness measurements and Energy Dispersive X-ray (EDX). Calcium carbonate growth, under flow conditions, has been assessed for each of the surfaces by studying the amount of scale and the morphology of the crystals using Scanning Electron Microscopy (SEM). From the results, a systematic ranking of the surface resistance to scaling has been established together with an improved description of the scale deposition process.