Petroleum solid adherence on tubing surface

XPS analysis of petroleum well tubing adherence

“…3(b)): magnetite (JCPDS 44-1415), lepidocrocite (JCPDS 44-1415) and goethite (JCPDS 29-0713); pyrrhotite disappears, as Mössbauer spectroscopy has shown in previous work. 6 Additionally, compounds such as barite (JCPDS 29-0202), aluminium silicate (JCPDS 46-0037) and montmorillonite clay (JCPDS 07-0051) were identified in this sample. The diffractogram background in Fig.…”

“…2, whereas the inner layer determined by SEM is ¾15 µm. 6 The detached outer layer composition determined by combustion and AAS is presented in Table 1. The outstanding metals detected in this sample are Fe, Ca and Ba, which can be related to steel surface corrosion products, reservoir rock and drilling-mud compositions, respectively.…”

“…1(a). 5,6 Most of the outer layer separates easily from the inner layer. The chemical information obtained by means of Fourier transform infrared spectroscopy (FTIR) indicates an abundance of linear and cyclic hydrocarbons, aromatic rings and carbonyl and amino groups on the inner layer surface.…”

“…5 Morphological and chemical transformations of a metallic surface as a consequence of its exposure to a petroleum environment has been associated with acidic corrosion in the presence of H 2 S and CO 2 gases, therefore iron compounds such as oxidized magnetite, pyrrhotite and iron hydroxides identified by Mössbauer spectroscopy in a previous work in the black inner layer scraped from the steel surface may be related to such phenomena. 6 This black material, naturally preserved under a layer of organic material, shows a low background in an XRD diffractogram when the steel surface is not exposed to the atmosphere. 6 Other steel transformations could be related to drilling-mud adherence to the tubing surface as a consequence of the drilling well operations.…”

“…6 This black material, naturally preserved under a layer of organic material, shows a low background in an XRD diffractogram when the steel surface is not exposed to the atmosphere. 6 Other steel transformations could be related to drilling-mud adherence to the tubing surface as a consequence of the drilling well operations. 7 Chemical modification of the steel surface is also associated with the metal dusting mechanism, which starts as low as 300°C and at a carbon activity greater than the unit.…”