Abstract
Oilfield scale formation is dependent upon the production of water; as a result most scale inhibitors are water soluble and deployed using an aqueous phase. For treatment of wells that produce only small amounts of water and/or have water sensitive matrices, the use of an aqueous inhibitor can cause many problems. Even with the development of oil miscible scale inhibitors the same problem can be encountered when the incorrect screening procedure has been used in the laboratory.
This study illustrates the importance of using the correct coreflood protocol when evaluating an oil soluble scale squeeze inhibitor. Examples of different procedures for different types of scale inhibitor show that use of the incorrect procedure can seriously influence the formation damage and lead to misapplication in the field. Three field examples are included, comparing laboratory evaluation and field specific studies of different types of scale inhibitor, explaining why different formation damage mechanisms are seen in the field and sometimes not recreated in coreflood experiments.
The study goes on to describe the development of a range of truly oil soluble scale inhibitors, which preclude any aqueous phases, and have been specifically developed to minimise formation damage caused by aqueous and oil miscible scale inhibitors. The products have been screened for use in several fields which have historically had formation damage issues with both aqueous and oil miscible scale inhibitor squeeze products. Finally, the paper will talk about the consequences this has for field application based upon a field trial using the new, truly oil soluble scale inhibitor.
