As the oil and gas industry strives to replace ageing, environmentally undesirable scale inhibitors there is an ever increasing use of polymeric inhibitors. Incorporation of phosphorus functionality into a polymer backbone has been shown to improve inhibition efficiency, enhance adsorption characteristics and allow the polymer concentration to be analysed by elemental phosphorus. It is known that some phosphorus tagged polymers can be problematic to analyse in oil field brines as they typically have a low phosphorus content which is difficult to determine from the background.
The development of novel phosphorus functionalised polymeric scale inhibitors was previously described (SPE 130733). This paper follows the development of the inhibitor class. Utilising extensive laboratory testing the interactive nature of the scale inhibitors and reservoir lithology was studied. These novel phosphorus functionalised inhibitors were compared to a number of other available P-containing polymers.
Following successful development, one of the phosphorus functionalised polymeric inhibitors was subject to sequential field-trial in a harsh BaSO4 scaling, highly naturally fractured North Sea carbonate reservoir. The phosphorus functionalised inhibitor provided improved performance compared to the incumbent product. Following the successful deployment in a carbonate reservoir the novel inhibitor class was also deployed in a number of North Sea sandstone reservoirs and one field wide case study is reported with details on the innovative management and implementation strategy presented. Focus has been given to the application of these products and a detailed analysis of field proven benefits given.
This paper concludes with a detailed comparison of these Phosphorus functionalized scale inhibitors with the incumbent products they have replaced in the case histories described. The benefits that these novel, innovative products have given to the operator are described along with a technical synopsis of incremental performance benefits.