Determination of the zone of maximum probability of asphaltenes precipitation utilizing experimental data in an Iranian carbonate reservoir

Asphaltenes precipitation is one of the major operational problems affecting oil production in the Bangestan reservoir in south of Iranian fields. Precipitation of asphaltenes in reservoirs, wells and production facilities can have severe detrimental impact on the economics of oil production because of a reduction of well productivity and/ or clogging of production facilities. 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. Knowing the saturation pressure and the flocculation onset pressure, the methodology allows the determination of the most probable range of depth at which asphaltenes precipitation will occur. The purpose of this methodology is 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 paper, field applications of the methodology are shown. Depending on the depth range of asphaltenes precipitation occurrence,reperforation of the producing interval, hydraulic fracture is recommended