A Novel Method for Mitigation of Asphaltene Deposition in the Wellstring

Asphaltene precipitation and deposition is a serious problem in many iranian fields.the deposited asphaltene results in partial or total blockage of the wellbore and wellstring reducingor completely seizing oil production. this paper studies the asphaltene problem and mitigationmethods in wellstring systematically. it presents new approach based on the combinationof thermodynamic modeling of asphaltene precipitation with hydrodynamic well modeling.the developed model is capable to determine the asphaltene precipitation and depositioninterval through the wellstring. therefore, it could study the effect of hydrodynamic parameterssuch as wellhead pressure, well flow-rate and tubing size on the mitigation of asphaltenedeposition. the conventional way to treat asphaltene deposition was through remediationwhich attacks the problem after it occurs. this model is capable to determine the severityof asphaltene deposition even before start of production. the model was applied to simulatethe asphaltene precipitation in one of the south iranian oil fields (kupal) and important guidelineshave been studied to mitigate the risks associated with asphaltene deposition. the resultsof modeling show that change in hydrodynamic condition could reduce and mitigate asphaltenedeposition damage. but in some cases it would not be possible to prevent asphaltene precipitationcompletely. therefore, the approach for flow assurance in those cases would be to changethe well completion and inject asphaltene inhibitor, in order to prevent deposition of asphalteneflocculates.