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AbstractAsphaltenes precipitation is one of the major operational problems affecting oil production in the Northern Monagas fields of Eastern Venezuela. Being a phenomena that depends primarily on crude composition, pressure and temperature, it may occur inside the pore space, downhole along the producing strings, at the well head, inside flow lines, separators and gas treatment plants. In most cases, the cleaning of pipes and production strings is done through chemical treatment. For downhole treatment, coiled tubing or snubbing units have to be used, thus increasing production costs. A field methodology based in the influence of pressure in asphaltenes precipitation has been designed and implemented to estimate the zone of maximum probability of asphaltenes precipitation. Nodal analysis is applied to determine pressure versus depth behavior at the well for different operational conditions. Gross composition chemical analysis and asphaltenes dispersion curves of the crude oils are required. Knowing the saturation pressure and the flocculation onset pressure, the methodology allows the determination of the most probable range of depths at which asphaltenes precipitation will occur. The purpose of this methodology is to determine the optimum operational conditions that maximize production at minimum risk of asphaltenes precipitation, as well as to select the better preventive measure for each particular case, thus maintaining overall control of the asphaltenes plugging problem. In this work, field applications of the methodology are shown. Depending on the depth range of asphaltenes precipitation occurrence, reperforation of the producing interval, hydraulic fracturing or chemical treatment is recommended. Application of the methodology is becoming routine in the Northern Monagas fields. An expert system based on the methodology is under development to extend its application throughout the area
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