Poor production and abnormal productivity decline in some wells could be traced back to drilling and well completion practices. These wells could be drilled with water based mud and completed with sand control equipment such as slotted liners and gravel pack assemblies that introduce another dimension of damage. Drilling operation is characterized by moderate to severe mud losses that could result in water block and deep penetrating damage, especially if the wells are not cleaned up immediately after drilling and are further delayed in coming on stream. If the wells are then brought into production without wellbore cleanout to remove the drilling mud induced damage, observed trends from the start-up of production in such field could be indicative of the skin damage magnitude in the well. Potential pay zones have been misdiagnosed as nonproductive, and payout on investment has been delayed because of formation damage.

Engineering work and technology-based solutions, which encompass diagnosis of damage mechanism, laboratory testing, formulation and optimization of treatment fluids, job design and field execution procedures will be required to mitigate the formation damage. Laurel Energy applies the micro-emulsion well enhancement treatment technology that has yielded great successes in removal of formation damage, resulting in high incremental oil production with fast payback times. Evaluation of past micro-emulsion technology applications have revealed that water-block with its associated high Interfacial Tension (IFT) against the oil constitutes a serious impediment to the well productivity.

It is however important to recognize whether the poor production performance is due to a combination or any of the following factors:

• Poor reservoir quality
• Inflow performance or near wellbore damage
• Sub-optimal vertical lift performance
• Completion string capacity constraint
• Loss of reservoir pressure or pressure decline
• Surface facilities capacity constraints

Information obtained from geological and geophysical studies, logs, drilling and well completion data, production data, helps in establishing the type of formation damage. Finally, proper diagnostic tools are required to identify, quantify, and prevent formation damage effects on productivity.

We integrate field and laboratory methods for recognition, prevention, and treatment of formation damage. We have developed laboratory and engineering techniques for proper evaluation of different damage mechanisms and optimization schemes for effective treatments.