How Scale Inhibitors Benefit Oilfield Production

Scale deposits are the most common and most troublesome damage problems in the oilfield. These deposits can occur in both production and injection wells, as solid deposits grow over time, blocking and hindering fluid flow through pipelines, valves and pumps, reducing production rates and leading to equipment damages. While scale inhibitors are not effective in removing scale buildup that already exists, adding scale inhibitors into production fluids makes it possible to slow or prevent buildup of scale in oil wells, preventing any costly reduction in productivity for that well site. The removal of existing scale deposits, depending on the type and severity, may require chemical and possibly mechanical means of removal.

Scale deposition occurs when the solution equilibrium of the water is disturbed by pressure and temperature changes, dissolved gasses or incompatibility between mixing waters. Water sampling and field analyses are the first steps to determine if, and what type of, scaling is present in your production operations. Using field testing that includes a comprehensive survey of the production services and equipment used in specific production phases, as well as state of the art laboratory analysis, it is then possible to develop a protocol to resolve these issues using the appropriate oilfield scale inhibitors. 

TESTING AND ANALYSIS

• In addition to collecting samples to test the pH, alkalinity, and presence of CO2 and iron in the water sample while in the field, laboratory analysis will be needed to determine the specific type and penetration of the buildup. Since scale deposits can be caused by the presence of a number of different chemicals present in the soil at the drilling site, these chemical analyses make it possible to determine the proper scale inhibitor to use to combat the cause of scale in a specific area. This is not a one-size-fits-all approach and in many situations a mixture of chemicals may be developed to respond to specific environmental conditions.

TREATMENT METHODS – HOW DO SCALE INHIBITORS WORK?

• Once the composition of the buildup has been identified, it is then possible to determine the proper mitigation efforts to combat the production and buildup of scales. The most efficient and cost effective techniques for implementing include continuous injection or chemical scale squeeze treatment in order to properly address the presence of scale-causing compounds.

• • During Continuous Injection, these scale inhibitors, whether an organic or inorganic product, should be applied as far upstream as possible from the source of the scaling to allow the chemicals to work properly. Based on the level of buildup, various concentrations and compounding of chemicals may be necessary to prevent further accumulation. In this mechanism, the scale inhibitor interacts with growing scale crystals. The scale inhibitor acts as a nucleation center that covers the scale formed in the aggregate. Thus, active crystal growth sites are blocked and further crystal growth is stopped.
  • Chemical Scale Squeeze Treatment involves injecting three solutions into the production well, consisting of a preflush solution, pill solution, and overflush solution. After the injection of the three solutions, the well is shut-in for about 24 to about 48 hours to allow the chemicals to permeate into the area and for the proper reactions to occur to prevent future growth.

With more than a century of combined industry experience, DynaChem understands the importance of protecting your assets during oil and gas exploration, and the buildup of scales in production equipment can cause costly delays in production as well as reducing output at the well site. Our unmatched ability to understand operator challenges and custom blend to specific applications have given DynaChem the well-deserved reputation of delivering best-in-class results for oilfield scale inhibition even in the most challenging environments.