Formation Damage can be defined as any near wellbore alteration that affects permeability due to well operations. Use of any tool(s) to avoid or rectify formation damage may be helpful in terms of reducing costs or improving hydrocarbon recovery. These tools may either indicate or predict the changes in near wellbore permeability, and may identify the cause and suggest alternative well operations and/or specific remedial treatments to improve hydrocarbon recovery. A new tool has been identified to realise and help unlock the hidden potential of marginal fields at the exploration and appraisal stage. This is a tool based on multi-criteria decision analysis that combines the use of pre-existing geological and reservoir conditions core flood laboratory analysis, which predominantly compares datasets before and after simulations of well operations to enhance formation damage evaluation and assist in making cost benefit descisions. Existing geological and well data can be combined with a comprehensive formation laboratory study, to effectively create a new tool which, based upon multi-criteria decision analysis, can assist in making cost benefit decisions.
The majority of formation damage laboratory testing is performed during field development in order to determine the least damaging drilling, completion and injection fluids and procedures. This analysis has now become routine and is part of field development planning for most major operators. Formation damage evaluation should also be conducted at other times in the life of a field or well. The reservoir can be damaged or can suffer damage mechanisms throughout its exploration, appraisal and development history. By understanding damage from the day the first drill-bit penetrates the field we can develop a greater understanding of reservoir potential. Full simulation of drilling, completion and production of exploration and appraisal wells can unlock hidden potential in marginal fields.
Examples of the impact of formation damage on well performance and some examples of formation damage investigation and remediation will be discussed. Specific examples of how formation damage has been used to re-value potential of marginal discoveries and has led to successful development will be presented.