This paper presents the results of an investigative case study to determine, solve and prevent the causes of the loss of production due to the pressure drop grown in the section line between the wellhead and the air cooler in a well located in the north of Italy in a field experienced of asphaltene deposition.

It is well known that one of the most critical flow-assurance problems involves the build-up of asphaltenes deposits in wellbores and pipelines that reduce production and so the early chemical strategy was to inject asphaltene inhibitor.

The peculiar aspect was quickly increasing of water cut and with oil productivity decline aggravated by subsequent formation of tight emulsions and scales deposits. An accurate analysis of the fluids properties and process parameters was necessary to analyze and solve the problems.

The study focused on a comprehensive laboratory analyses and field investigation to evaluate the risk of scale deposition associated to asphaltenes precipitation and emulsion formation and identify the appropriate chemical strategy as the starting chemical approach was not sufficient to guarantee the production.

Based on the results a special solvent treatment was recommended and designed to remove deposits. The treatment was based on asphaltene solvent tailed with batch of HCl. The results of the field trials will be described in the paper. The treatment resulted in a good decreasing of the pressure drop of the line and the maintaining of the production.

At last a chemical strategy was identified to prevent deposit build up in order to avoid any future criticalities. Due to the single injection point at wellhead, the scale deposition issue is controlled without problem using a combined anticorrosive and antiscale chemical.

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