Pros and Cons of Open Hole Completion

Advantages:

• It has a lower cost and a simpler design

• Provides maximum exposure to the pay zone increasing productivity index and performance of the well

• Lower pressure losses due to larger diameter conduit

• Causes less formation damage – Since the reservoir section is drilled using non-damaging drilling fluid and is not cemented or perforated, less formation damage occurs. Less damage keeps the reservoir close to original conditions not requiring severe stimulation efforts.

• The well can be deepened in the future if required

• Completion can be modified in the future by running a liner if required

Disadvantages:

• There is a higher risk of hole collapse – Since there is no mud cake or cemented casing to support, less consolidated rock could collapse during production.

• There is no control on sand production – Small sand production can be managed through not-so-expensive means, but major sand production could require major workover operations.

• There is limited zonal isolation – If there are multiple zones open containing different fluids, the production cannot be easily controlled.

• It is difficult to carry out selective zonal stimulation – Since there is limited zonal isolation, stimulation fluid could go to the high permeability zone leaving the lower permeability zone improperly stimulated.