Addressing Paraffin Deposition Challenges Through New Technologies

Abstract

Paraffin deposition is a common challenge for production facilities globally where production fluid/process surface temperature cools down and reach below the wax appearance temperature (WAT) of the oil. Although chemical treatment is used widely for suitable mitigation of wax deposition, conventional test methods like cold finger often fail to recommend the right product for the field. The current study will present development of two new technologies PARA-Window and Dynamic Paraffin Deposition Cell (DPDC)to address such limitations. Large temperature gradient between bulk oil and cold surface has been identified as a major limitation of cold finger. To address this, PARA-Window has been developed to capture the paraffin deposition at a more realistic temperature gradient (5°C) between the bulk oil and surface temperature using a NIR optical probe. Absence of brine and lack of shear has been identified as another limitation of cold finger technique. DPDC has been developed to study paraffin deposition and chemical effectiveness in presence of brine. Specially designed cells are placed horizontally inside a shaker bath to achieve good mixing between oil and water for DPDC application. A prior study by Russell et al., (2019) showed the effectiveness of PARA-Window in capturing deposition phenomena of higher molecular weight paraffin chains that resemble closely to field deposits under narrow temperature gradient around WAT. Conventional test methods fail to capture meaningful product differentiation in most oils under such conditions and hence can only recommend a crystal modifier type of paraffin chemistries. PARA-Window technique can expand product selection to other type of paraffin chemistries (paraffin crystal modifiers, dispersants and solvents) as shown earlier by Russell et al., (2021). The usage of DPDC allows us to create a dynamic mixing condition inside the test cells with both oil and water under a condition similar to production pipe systems. This allows DPDC to assess water effect on paraffin chemistries (crystal modifiers and dispersants). This study presents the usage of these two new technologies to screen performance of different types of paraffin chemistries on select oils and their advantages over cold finger. The results identify how mimicking field conditions using these new technologies can capture new insights into paraffin products.