Study on Deodorizing Thermally Desorbed Oil from Oil Cuttings

Oil cuttings produced in drilling with oil base drilling fluids are generally cleaned by thermal desorption method which, when heating the cuttings at high temperatures, produces bad smelled oils, seriously affecting the recycling and reusing of the oils obtained from the cuttings. Generally speaking, the bad odor comes from the volatile components with bad odor in the oils. Using oil distillation, the low-boiling-point components of the oils desorbed from drilled cuttings (obtained from field diesel oil base mud) were obtained and were deodorized with various methods, such as acidolysis, adsorption-centrifuging and distillation. The components of the oils desorbed from drilled cuttings were ascertained with GLC-MS and the bad odor from the thermally desorbed oils was analyzed. It was found that the content of the fraction in the thermally desorbed oils with boiling point less than 150℃ was 2.5%, and it is this light fraction who produces the bad odor. By acidolyzing or adsorption-centrifuging, the thermally desorbed oils still contain some low boiling point olefins, making the bad odor very difficult to remove. Distillation can effectively remove the low boiling point components from the thermally desorbed oils. The high boiling point components can be reused to mix oil base mud. This method is effective and efficient and is easy to perform in field application.