Inhibitor Selection for Iron-Scale Control in MEG Regeneration Process
- Hua Guan (M-I SWACO) | George Cole (M-I SWACO) | Paul J. Clark (M-I SWACO)
- Document ID
- Society of Petroleum Engineers
- SPE Production & Operations
- Publication Date
- November 2009
- Document Type
- Journal Paper
- 543 - 549
- 2009. Society of Petroleum Engineers
- 4.3.4 Scale, 1.8 Formation Damage, 5.4.10 Microbial Methods, 5.4 Enhanced Recovery, 4.2.3 Materials and Corrosion, 4.3 Flow Assurance, 4.3.1 Hydrates, 5.4.2 Gas Injection Methods
- 4 in the last 30 days
- 444 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 10.00|
|SPE Non-Member Price:||USD 30.00|
The formation of iron-containing scale because of highly dissolved iron content and increased pH (= 8.5) has been observed in a monoethylene glycol (MEG) regeneration system. The control of iron-scale deposition under these harsh conditions causes recurring problems in the reboilers, requires frequent filter change-outs, and remains a challenge to the field. To investigate this problem, a modified corrosion-testing apparatus was employed to replicate the iron-scale formation. It evaluates the performance of selected chemicals under realistic field conditions (specifically, low pH caused by carbon dioxide dissolution; higher pH because of carbon dioxide boiling off from the reboiler; and alkali addition for corrosion control). Both pH and iron levels (including dissolved iron, ferrous iron Fe2+, and total iron) were closely monitored. Additional digital photos were taken at various stages.
There are several challenges associated with the inhibition of iron scale in systems with a high iron level (= 150 ppm), high MEG content (= 60%), and high pH (= 8.5). These factors contribute to incompatibility and poor inhibition by conventional inhibitor species. A number of scale-inhibitor (SI) products, scale dissolvers, and blends were tested under aerobic or anaerobic conditions. One product greatly reduced the rate of scale formation and indefinitely delayed scale formation at higher dosage. This product also showed the capability to redissolve deposits already present in the system.
Evaluation of iron-scale inhibitor is a challenge because of the debatable iron-poisoning effect and the lack of a standard laboratory method. In this paper, the propensity of various iron deposits (e.g., iron carbonate and insoluble iron/inhibitor complex) is discussed. Moreover, the formation of a soluble iron/inhibitor complex is quantified. This could have important implications for the remediation of iron-containing scale.
|File Size||414 KB||Number of Pages||7|
Boak, L.S., Graham, G.M., and Sorbie, K.S. 1999. The Influence of Divalent Cations onthe Performance of BaSO4 Scale Inhibitor Species. Paper SPE 50771 presentedat the SPE International Symposium on Oilfield Chemistry, Houston, 16-19February. doi: 10.2118/50771-MS.
Dyer, S., Orski, K., Menezes, C., Heath, S., MacPherson, C., Simpson, C.,and Graham, G.M. 2006. Development of Appropriate TestMethodologies for the Selection and Application of Lead and Zinc SulfideInhibitors for the Elgin/Franklin Field. Paper SPE 100627 presented at theSPE International Oilfield Scale Symposium, Aberdeen, 30 May-1 June. doi:10.2118/100627-MS.
Dyer, S.J. and Graham, G.M. 2000. The influence of iron on scale inhibitorperformance and carbonate scale formation. Presented at the 11th NIFInternational Oil Field Chemical Symposium, Geilo, Norway, 20-22 March.
Graham, G.M., Boak, L.S., and Sorbie, K.S. 1997. The Influence of Formation Calcium onthe Effectiveness of Generically Different Barium Sulphate Oilfield ScaleInhibitors. Paper SPE 37273 presented at the International Symposium onOilfield Chemistry, Houston, 18-24 February. doi: 10.2118/37273-MS.
Graham, G.M., Collins, I., Stalker, R., and Littlehales, I.J. 2002. The Importance of AppropriateLaboratory Procedures for the Determination of Scale Inhibitor Performance.Paper SPE 74679 presented at the International Symposium on Oilfield Scale,Aberdeen, 30-31 January. doi: 10.2118/74679-MS.
Graham, G.M., Stalker, R., and McIntosh, R. 2003b. The Impact of Dissolved Iron on thePerformance of Scale Inhibitors Under Carbonate Scaling Conditions. PaperSPE 80254 presented at the International Symposium on Oilfield Chemistry,Houston, 5-7 February. doi: 10.2118/80254-MS.
Graham, G.M., Stalker, R., Williams, H.L., and Littlehales, I.J. 2003a. Theimpact of dissolved iron on the performance of scale inhibitors under carbonatescaling conditions. Paper 17 presented at the NIF 14th International Oil FieldChemicals Symposium, Geilo, Norway, 24-26 March.
Guan, H. and Cole, G. 2008. The formation and control of iron scale in a MEGregeneration system. Proc., 19th International Oil Field ChemistrySymposium, Geilo, Norway, 9-12 March.
Hill, P.I., Graham, G.M., Dyer, S.J., and Coleman, J. 2000. Iron Release Following MineralDissolution Following Scale Inhibitor Application in a North AlaskanReservoir. Paper SPE 58727 presented at the SPE International Symposium onFormation Damage Control, Lafayette, Louisiana, USA, 23-24 February. doi:10.2118/58727-MS.
Iron Ferrous Method 8146 and Iron (Total) FerroVer Method 8008. 2007. HatchCompany, http://www.hach.com.
Johnson, T., Roggelin, C., Simpson, C., and Stalker, R. 2005. Phosphonatebased scale inhibitors for high iron and high salinity environments. Presentedin Session 6 of the Royal Society of Chemistry Conference on Chemistry in theOil Industry IX, Manchester, UK, 31 October-2 November.
Sorbie, K.S. and Laing, N. 2004. How Scale Inhibitors Work: Mechanismsof Selected Barium Sulphate Scale Inhibitors Across a Wide TemperatureRange. Paper SPE 87470 presented at the SPE International Symposium onOilfield Scale, Aberdeen, 26-27 May. doi: 10.2118/87470-MS.
Stoppelenburg, L.S and Yuan, M.D. 2000. The performance of barium sulphateinhibitors in iron containing waters in both aerated and anaerobic systems.Paper No. 00114 presented at CORROSION/2000, NACE International Conference,Houston, March.