Mitigating paraffin deposition in production lines has remained a critical issue for the oil industry to control the associated production and transportation cost. Recently, injection of paraffin inhibitors in the transportation pipelines has been widely used along with other strategies to improve production. This study investigates the effect of operating temperatures and geometries on the performance of paraffin inhibitors. Moreover, the experimental temperature differences (i.e. changes in coolant temperature and bulk oil temperature) strongly influence the inhibitor efficacy indicating that these conditions must be optimized prior to field applications.

The experiments were conducted with a Caspian Sea (CS) condensate at different temperature conditions using two paraffin inhibitors (Maleic anhydride co-polymers: PI-B and PI-C, where PI-B has a higher carbon chain length than PI-C). The inhibitor concentration of 500PPM and a 24h time duration is maintained for all the experiments. The deposit mass and wax content were analyzed.

Wax mass flux increases with the increasing temperature difference in constant bulk oil temperature experiments. In contrast, the mass flux increases first and then decreases with the decrease in the temperature difference in constant coolant temperature experiments. Hence, it is important to consider the influence of operating conditions that may change the oil properties significantly and ultimately the magnitude of the paraffin deposition. Deposit mass (decreased) and wax content (increased) are significantly influenced by the presence of inhibitors. The inhibitor efficacy, that incorporates both deposit mass and wax content, is calculated at different operating temperature differences. It has been observed that the efficacy strongly varies with the operating region. Hence, it is necessary to select proper inhibitors based on the local operating temperature conditions during injection.

This study provides a fundamental understanding between operating parameters and inhibitor efficacy. The usage of inhibitors is highly complicated and the knowledge obtained through this investigation disseminates crucial information on selecting proper inhibitor for field applications.

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