In-situ monitoring the inhibiting effect of DETPMP on CACO₃ scale formation by synchrotronx-ray diffraction

The formation of calcium carbonate mineral scale is a persistent and expensive problem in oil and gas production. The aim of this paper is to further the understanding of scale formation and inhibition by in-situ probing of crystal growth by synchrotron radiation Wide Angle X-Ray Scattering (WAXS) in the absence and presence of DiEthyleneTriaminePenta (MethylenePhosphonic acid) (DETPMP) scale inhibitor at elevated temperature. It has been shown that the nucleation and growth of various calcareous polymorphs and their individual crystal planes can be followed in real time and from this the following conclusions are reached. Two stages of scale formation have been identified: unstable and stable stages. DETPMP significantly increases the induction time obviously at 10 ppm. DETPMP suppresses calcite formation and favours vaterite formation. DETPMP causes the change of lattice parameters of calcite crystals.calcium carbonate, scale, inhibition, DETPMP The crystallization of mineral scale and its inhibition have been followed in-situ and as such, information on the nucleation and growth processes are accessible. This technique offers an exciting prospect for the study of scaling. © 2007 by NACE International.