Factors affecting the thermal stability of conventional scale inhibitors for application in high pressure/high temperature reservoirs

S. J. Dyer, G. M. Graham, K. S. Sorbie

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    21 Citations (Scopus)

    Abstract

    Following an earlier paper (SPE 37274, 1997), we have continued to investigate the thermal stability of scale inhibitors for application in high pressure/high temperature (HP/HT) reservoirs. HP/HT reservoirs are currently under development in the North Sea and are characterized by high salinity brines (TDS>300,000 ppm) high temperatures (T>175 °C) and high pressures (12,000-15,000 psi, approximately 800-1050 bar). At present produced brines are treated with scale inhibitors to prevent mineral scale deposition within tubulars and topside equipment. However, the conventional polymer and phosphonate scale inhibitors currently being used may not be appropriate for application in the harsh HP/HT reservoirs. In this work, results are presented from static thermal stability tests conducted on conventional polymer and phosphonate scale inhibitors including phosphino-polycarboxylate (PPCA), polyvinyl sulphonate (PVS), penta-phosphonate (DETPMP) and hexa-phosphonate (TETHMP). The stability of the scale inhibitors has been considered at temperatures ranging from 120 °C to 200 °C and other factors which may affect thermal stability have also been investigated, including solution pH and the presence of oxygen radicals, iron and common cations (Na+, Ca2+, Mg2+) in the inhibitor solution. The results from this work demonstrate how factors such as pH and brine composition control thermal stability. Furthermore, the controlling influence of certain factors, such as solution pH, affect different species differently. This work assists in the selection of scale inhibitors for use in HP/HT applications.

    Original languageEnglish
    Title of host publicationProceedings of the 1999 SPE International Symposium on Oilfield Chemistry
    Pages167-177
    Number of pages11
    Publication statusPublished - 1999
    EventSPE International Symposium on Oilfield Chemistry - Houston, United States
    Duration: 16 Feb 199919 Feb 1999

    Conference

    ConferenceSPE International Symposium on Oilfield Chemistry
    CountryUnited States
    CityHouston
    Period16/02/9919/02/99

    Fingerprint Dive into the research topics of 'Factors affecting the thermal stability of conventional scale inhibitors for application in high pressure/high temperature reservoirs'. Together they form a unique fingerprint.

    Cite this