Coiron Amargo Sureste is a Pan American Energy area located in the Neuquen basin which currently has 13 unconventional oil wells under production. One of these producing wells presents an unstable production pattern which is associated with the presence of slugging. In fact, the present work focusses on the application of strategies to improve its extraction system. A pilot test for injecting a foaming agent suitable for high cut crude oil through a capillary system was carried out at an estimated depth of 2750 m. The chemical treatment implementation, as well as its control, monitoring, and evaluation, were combined in an operational strategy specifically designed for this purpose. Firstly, the initial step was a laboratory test following an adaptation of the standard ATSM-D892 in which a Nonionic/Amphoteric surfactant was selected. Subsequently, the designed product was tested in a 15-day field trial in which daily data involving oil production and foam breakdown was continually collected. The selected product was injected through a batch mode having the well closed for 12 hours to recover pressure. Afterward, a continuous dosage of 250 ppm concentration was injected through the downhole capillary system. Obtained results showed an average oil production increase of 1.7 m3/d (10.7 bpd) during the surfactant injection. Due to these significant results, the surfactant was continuously injected for several months until the artificial lift method was changed.
During the regular life cycle of oil and gas wells, there is a common reduction in the bottom hole pressure (BHP) over time that leads to produce liquid loading problems. It means that the well doesn’t have proper liquid production since gas velocity is not strong enough to mobilize that liquid phase, leading to its accumulation on production tubing.
The application of foaming chemicals is a common strategy in gas wells with liquid loading problems since these products, by reducing the critical velocity of the gas phase, facilitate the transport of liquids to the surface. Simultaneously, this reduction in critical velocity helps to lower relative density of accumulated fluids and, therefore, reduced back pressure. This foaming chemicals are commonly applied through different ways: downhole capillaries for continuous injection; liquid batch; or solid bars directed into the production tubing.
