ASSESSMENT OF PTEROYL-L-GLUTAMIC ACID BASED INHIBITORS TO MITIGATE SILICATE SCALES DURING ALKALINE-SURFACTANTPOLYMER FLOODING

Silicate scale may precipitate and deposit during Alkaline-Surfactant-Polymer (ASP)
flooding, resulting in constriction to the flow of fluid during oil production. Unlike
other traditional scales, silicate scales formation in the oil field is a complex and
poorly understood. Among other factors, its precipitation largely depend on pH,
temperature and divalent ions concentrations. Once formed, silicate scale is very
difficult to remove and it has been removed via drilling in the past. However,
removing scale by this method causes formation damage, among other disadvantages.
In recent years, the chemical treatment has taken over in the treatment of silicate
scales. In spite of the large volume of work carried out on chemical inhibitors, none
has provided an effective method of controlling the troublesome silicate scale.
Furthermore, conventional chemical inhibitors are subjected to increasing strict
regulations. Therefore, alternative green scales inhibitors such as COM6 Polyaspartic
acid, Pteroyl-L-glutamic acid (PGLU) are beginning to get attention. Aspartic acid is,
together with glutamic acid, classified as an amino acid.