Mobil North Sea Limited (MNSL) have been conducting treatments to prevent both Carbonate and Sulphate scale formation in the Beryl Field since the early 1980's. In order to effectively prevent scaling without frequent treatments, a novel method of increasing the squeeze life of the scale inhibitor has been developed. This method is based on the use of a proprietary extending agent. This results in greater retention of the scale inhibitor within the formation and substantially reduced inhibitor backflow during the initial production following the squeeze. The inhibitor is then released from the formation at a low but effective concentration over a long period of time.
Following extensive laboratory studies, the first Mobil Long Life Scale Inhibitor (MLLSI) squeeze was performed on Beryl Well 9/13a-B16 in January, 1989. A squeeze life of fifteen months was obtained compared to an average life of about eight months from commercial treatments. Other wells in the Beryl Field have been treated subsequently and show improved treatment lives.
The benefits of the longer inhibitor life resulting from MLLSI include reduced deferred production and substantially lower inhibitor treatment costs.