An oilfield in the Middle East experienced both strontium sulphate and calcium carbonate scale depositions. The downhole scale inhibitor squeeze treatment strategy was initiated as one of the most effective methods to control challenges:
High salinity formation brine with a calcium concentration more than 15000 ppm.
Low water cut, < 10% in most wells.
Limestone formation with strong downhole fluid cross flows.
Relatively low reservoir pressure and gas lift is often utilized.

The reservoir temperature is about 80oC and pressure is less than 3000 psi. Due to concerns on formation damage, the treatment volumes were often limited to the small amounts of main pills and overflush. As a result, the scale inhibitor treatment life was impacted by these challenges. Since 2019, a research program has been initiated to select a suitable scale inhibitor candidate. In the meantime, the lab test plan was set up to develop an effective squeeze treatment additive to enhance the treatment life. Through the test program, a phosphonate scale inhibitor was identified and a new chemical additive was developed to meet the target of squeeze treatment enhancement. Field trials were carried out and a comparison between with and without the chemical additive was made. The initial field trial results demonstrated that the newly developed chemical additive can significantly enhance a downhole squeeze treatment lifetime by more than 30%. In this paper, full laboratory test results are presented. The field trial design methodology for how the chemical additive was applied is outlined. The field data with and without the application of the chemical additive are discussed.