A Fundamental Micro Scale Study of the Roles of Associated Gas Content and Different Classes of Hydrocarbons on the Dominant Oil Recovery Mechanism by CWI.

Various studies demonstrated new gaseous phase formation and oil swelling and viscosity reduction are the oil recovery mechanisms by carbonated water injection (CWI) with new gaseous phase formation being the major recovery mechanism for live oil systems. However, none of the previous studies investigated the influences of dissolved gas content of the oil and oil composition, on the new gaseous phase. This study attempts to provide insights on this area. Based on the results, during CWI as CO2 partitions into the oil the dissolved gas of the oil liberates, which leads to in-situ new gaseous phase formation. The dissolved gas content of the crude oil has a direct impact on the saturation and growth rate of the new gaseous phase. The new gaseous phase doesn't form for oils that have an infinite capacity for dissolving CO2, such as light pure hydrocarbon components. Oils with limited capacity for dissolving CO2, such as heavy hydrocarbon components, are responsible for the formation of the new gaseous phase. Therefore for a live crude oil, the relatively heavier fractions of oil are responsible for triggering of the new gaseous phase and light to intermediate oil components control the further growth of the new gaseous phase.

Early coverage of upper extremity electrical injury wounds.

BACKGROUND: An appropriate and well-timed surgery has great impact on a patient's treatment and can prevent further damage to partially injured structures which if untreated will be lost leading to severe disability. In the present study we report our experience with early coverage of electrically injured upper extremity vital structures with encouraging results. OBJECTIVES: The aim of this study was to evaluate the results of early flap coverage (less than two weeks) after electrical injury in the induced wounds of upper extremity. MATERIALS AND METHODS: The records of electrically injured patients referred during a 10- year period to Firuzgar Medical Center were evaluated. After one or two sessions of debridement, the wounds were covered by distant or pedicled flaps and the results were evaluated according to the number of surgeries, complications and return to work time. RESULTS: Thirty patients were registered in this study, mean age at the time of injury was 26.43 (SD = 10.41) years; 40% of patients had right upper extremity injury, 23.3% had left and 36.7% had bilateral injury. 43.4% of patients had no complications, amputation rate was 23.3% and nerve injury was seen in 13.3% of patients. Mean days of return to work was 132.57 (SD = 64.99). In 11 patients distant flaps were used, 9 patients with graft only and 7 patients had a combination of graft and regional flaps.The dominant hand involvement in electrical injury is very high. CONCLUSIONS: We suggest that the routine treatment protocols of serial debridement until all the wound acquires a bed of granulation tissue should be revised, because the vital structures such as tendons and nerves will have undergone dessication necrosis and a young worker will be crippled for life. Early coverage of partially injured vital structures is gaining acceptance and this paper confirms the above mentioned treatment protocol.