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Paraffin buildup in flowlines and interface complicates field operations

A customer operating in the Ogston field of central Alberta produces primarily from the Granite Wash, Slave Point, and Keg River Formations. The customer had been experiencing paraffin deposition in lease flowlines, a common occurrence in the area. Despite a paraffin deposition program in lease flowlines, the operator was reporting an increase in wax volumes collected during the pigging process. Additionally, a pad was forming at the interface of the FWKO flowline.

Schlumberger conducted a system review that included interface sampling and performance testing to select a qualified paraffin solvent product. Atmospheric conditions included temperatures ranging from 10 to 25 degC [50 to 77 degF] and pressure of 2.6 MPa [377 psi]. Field production was 1.2-m³/d [7.6-bbl/d of oil equivalent] natural gas, 30.3-m³/d [190.6-bbl/d] oil, and 771-m³/d [4,849-bbl/d] water.

PI-7302 dissolver tested and selected to dissolve paraffin buildup

Laboratory solvency tests performed on a deposit sample indicated that PI-7302 paraffin dissolver was the most effective at dissolving the deposit. The test results confirmed the success of the previous application of PI-7302 dissolver that was batched into flowlines when the FWKO experienced issues.

Following testing, PI-7302 paraffin dissolver was applied continuously at a rate of 1,800 ppm at two satellite locations upstream from the FWKO interface. Another injection point was established at the FWKO inlet at 3,000 ppm to avoid wax deposition on flowlines going into the treater. This flowline program supplemented a downhole paraffin dispersant application already in place. A solvent batch program was discontinued.

Dissolver reduces paraffin in pig returns and eliminates depositions at FWKO interface

The application of the PI-7302 dissolver reduced paraffin in the pig returns and eliminated it at the FWKO interface. A continuous program of applying PI-7302 dissolver was initiated, and since then, neither the flowlines nor the interface has experienced paraffin issues.