Abstract
Asphaltene deposition related damage is a well known phenomenon during production of highly under saturated volatile oil systems. It's modelling and control has been broadly documented although this last practice has been restricted to the near wellbore region where its impact seems to be maximum and where treatments can be effectively deployed.
The following paper presents a modelling approach for the estimation of the asphaltene deposition profile in highly under saturated volatile oil systems. This profile would allow predicting effective permeability loss as a function of pressure provided a set of asphaltene content measurements taken at wellhead through time. A simple asphaltene solubility model coupled with laboratory measurements are combined to propose a precipitation-deposition model that estimates expected k losses when thermo dynamical changes such as methane injection or pressure depletion are present. The output from the model which is a k function of pressure was incorporated into a single well model to match well's actual response after near wellbore dissolution treatments and after injection gas appearance in the drainage area. Laboratory tests consisted of core flooding experiments that allowed obtaining basic relationships between mass of asphaltene deposited and damaged Ko.
The present model was developed as a tool for benefit estimation if an asphaltene dissolution technique is applied at reservoir scale. The present approach is proposed as a simple and practical way of estimating asphaltene related damage in compositional volatile oil reservoirs.
