Formation damage can occur in the vicinity of the wellbore or far field in the reservoir. Organic and inorganic deposition such as asphaltene, paraffin, iron sulfide, barium sulfate and calcium carbonate are the most commonly encountered scale types of damage. Accidental interactions between the completion kill fluid after the perforation or the drilling fluid while drilling through the target zone are also major causes. The decline of well productivity is the first indication of formation damage and can be used as a determining factor of its severity. Therefore, the type of damage, the mechanisms, and controls need to be analyzed and predicted.
This paper presents a detailed and comprehensive review of formation damage including both the external and internal types and the far field and near-wellbore damage. Damage can be identified by observing changes mainly in the well productivity; however, it can be also observed using retrieved equipment such as logging tools and downhole pumps or due to the restricted entry of completion equipment such as inflow control devices (ICDs). The impact of well configuration on the formation damage and the remedy afterwards is also discussed in details.
The present study provides a solution and control criteria for the formation damage and a comprehensive mechanistic modeling is proposed. The model is applied by coupling reservoir modeling with the wellbore conservation equations through the pressure. The effect of horizontal laterals is included by developing three-phase transient equations to account for the flow rate change from toe to heel in the drain hole.