Best-in-Class Zinc Sulfide Scale Inhibitor for North Sea Application

Benefits

• Implemented a robust flow assurance strategy for mitigating against harsh zinc sulfide scales
• Outperformed incumbent chemistries, allowing the most economic control for sulfide scale to ensure process equipment operability 

Background

A major operator in the UK sector of the North Sea commissioned Clariant Oil Services to qualify a scale inhibitor for a new high pressure/high temperature/high salinity field development.

Following extensive modelling work, zinc sulfide production was identified as being a major risk to the new field development. Due to the severity of the scaling risk, Clariant Oil Services considered two products; a broad spectrum scale inhibitor that has a field-proven history of mitigating zinc sulfide scales and the new patented SCALETREAT ZFD sulfide control technology.

Laboratory testing was conducted using industry leading techniques, including stressed sulfide static jar tests and dynamic filter blocking tests. The results from the stressed sulfide static jar tests for the field-proven ZnS inhibitor and Clariant Oil Services‘ SCALETREAT ZFD technology are shown in Figures 1 and 2, respectively. A time/differential pressure plot for the dynamic filter blocking test is shown in Figure 3.

Figure 1: Zinc sulfide inhibition efficiency for field-proven ZnS inhibitor using field conditions with an excess of sulfide

Figure 2: Zinc sulfide inhibition efficiency for SCALETREAT ZFD technology using field conditions with an excess of sulfide

Figure 3: Field-proven ZnS inhibitor and SCALETREAT ZFD technology using field conditions in a dynamic filter blocking test

Innovation and Value Delivered

The laboratory testing demonstrated the enhanced performance that Clariant Oil Services‘ SCALETREAT ZFD technology offered over the existing best-in-class product being used in the field. Clariant Oil Services‘ understanding of the complex scale scenario and ability to develop and offer a suitable solution was commended by the customer.

Furthermore, the SCALETREAT ZFD technology has been identified as being crucial to the successful startup and ongoing flow assurance strategy for this new field development.