Inhibition and Removal of Low-pH-Fluid-Induced Asphaltic Sludge Fouling of Formations in Oil and Gas Wells

摘要

Many low pH fluids are used in the Petroleum Industry to treat oil and gas wells.These enclude acid fracs, pickling acid, near wellbore acid jobs and scale inhibitor squeeze chemicals. All of these fluids can cause asphaltic sludge (rigid film emulsion) in some wells that can reduce production of oil and gas, plug a well or oil wet the near wellbore formation by reacting with the asphaltenes or asphaltic resins in an oil. This paper will provide information on how low pH fluids react with asphaltenes or asphaltic resins in oil, explain why the standard test results may be inaccurate in predicting these reactions and present a non-standard method which has been used for a number of years to stop the formation of asphaltic sludge in any well at any iron concentration. Case histories of removal treatment of asphaltic sludge from wells and inhibition treatment will be presented.