For several recently developed oil fields conventional scale inhibitor chemistry has been found to be ineffective in controlling/preventing scale formation. The failure of these scale inhibitors has been due to several factors; most notably a combination of high barium and calcium ion levels with low bottomhole pH and high reservoir temperatures. BP operates one such field, the Miller reservoir. The development of a suitable scale inhibitor for Miller was considered essential to enable the field to be produced effectively without the use of more sophisticated and costly facilities, such as reverse osmosis units for seawater treatment prior to injection.

The development of more effective scale inhibitors was progressed by identifying a relationship between inhibitor performance and molecular structure. From this relationship, several inhibitors were developed which showed significant improvement over commercially available products when evaluated in the laboratory. The best inhibitor, PO-85, has now been produced under licence by a major chemical manufacturer, and is ready for deployment on Miller.

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