by Mark Podwysocki

Flow restrictions or blockages in oil and gas production systems are problems for oil and gas operators.   Crude hydrocarbons and water from the producing well have variable composition and phase separation often occurs.   Specialized treatments for “flow assurance” are necessary to prevent deposition of various compounds including paraffin, asphaltene, hydrates, and scale.

Paraffin, called “wax” in oilfield applications, is described as a mixture of mainly alkanes that may contain napthenes, aromatics, asphaltenes, resins, or inorganic solids.   The severity of the crude oil or gas flow restriction is dependent upon the type and location of the paraffin deposits.

Three major factors influencing paraffin deposition are: temperature change, pressure change, and turbulence.   Paraffin components in crude hydrocarbons can deposit with different consistency at surface or sub-surface locations including: the formation face, downhole pumps, tubing string, the wellhead, flow lines, treatment vessels, and storage tanks.

Paraffin treatment systems can be chemical, mechanical, or a combination of both.   Chemicals lower the pour point of the oil and change crude oil rheological properties (lower yield stress) to prevent the deposition of wax.   Oils with variable paraffin content and asphalt-resinous substances frequently require blended paraffin inhibitor compositions with different molecular weights.

Akzo Nobel Surfactants provides several chemical products for paraffin control that perform a range of functions: inhibition, dispersion, pour point depression, and slop oil treatment.   We will be introducing a new line of paraffin products in the second quarter of 2007.