When asphaltene is first deposited, the remediation is significantly less challenging that if the asphaltene has been allowed to sit many weeks inside a pipeline because those deposits tend to harden over time. If not cleared promptly, they accumulate and form thicker layers that are more difficult and time-consuming to remove. In extreme cases, coiled-tubing drilling might be needed to restore production.

The effect of aging on asphaltene deposition has been examined, for example, in [1] which used crystal microbalance with dissipation monitoring (QCM-D) experiments to investigate surface deposition of destabilized colloidal particles of asphaltenes and their subsequent removal by solvent rinsing. They showed that the properties of deposited films during solvent removal depend on the history of the deposit. Newly formed deposit films are removed immediately without significant change in their mechanical properties during removal. However, deposits that remain on the surface for an extended time are more difficult to remove and exhibit increased dissipation during the removal period,. Liquid-cell atomic force microscopy (AFM) confirmed that aged deposits swell when the quality of the solvent is improved by exchanging for a high asphaltene solubility solvent. Deposit swelling is accompanied by a change in film morphology, from particulate to continuous. Intrestingly they found that stubborn deposits of aged asphaltene films that remained after solvent rinsing, may be partly removed by flowing dissolved asphaltenes in good solvent. Hence, reinjection of asphaltenes during remediation could actually aid deposit removal, and, more generally confirms that they may commonly be a hysteresis of deposition and sloughing.

Real-time data from the Quantum RF Asphaltene Analyzer is thus useful not just to give an advanced warning to avoid production loss, but also to reduce repair cost from delays in remediation.

Other problems can happen if the asphaltene is not promptly removed, for example, over time, deposits can create uneven surfaces and localized corrosion. This not only compromises the structural integrity of the pipe but may also lead to leaks or failures that require more comprehensive and costly repairs.

References

1. Campen, S. M.; Moorhouse, S.J.; Wong, J. S.. S. "Effect of Aging on the Removal of Asphaltene Deposits with Aromatic Solvent". Langmuir 2019 Sep 17;35(37), pp. 11995-12008. https://doi.org/10.1021/acs.langmuir.9b01792