RESUMEN
In order to mitigate the loss circulation of oil-based drilling fluids (OBDFs), an oil-absorbent polymer (OAP) composed by methylmethacrylate (MMA), butyl acrylate (BA), and hexadecyl methacrylate (HMA) was synthesized by suspension polymerization and characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and scanning electronic microscopy (SEM). The oil-absorptive capacity of OAP under different solvents was measured as the function of temperature and time. The effect of the OAP on the rheological and filtration properties of OBDFs was initially evaluated, and then the sealing property of OAP particles as lost circulation materials (LCMs) was examined by a high-temperature and high-pressure (HTHP) filtration test, a sand bed filtration test, a permeable plugging test, and a fracture sealing testing. The test results indicated that the addition of OAP had relatively little influence on the rheological properties of OBDF at content lower than 1.5 w/v % but increased the fluid viscosity remarkably at content higher than 3 w/v %. It could reduce the HTHP filtration and improve the sealing capacity of OBDF significantly. In the sealing treatment, after addition into the OBDF, the OAP particles could absorb oil accompanied with volume enlargement, which led to the increase of the fluid viscosity and slowing down of the fluid loss speed. The swelled and deformable OAP particles could be squeezed into the micro-fractures with self-adoption and seal the loss channel. More important, fluid loss was dramatically reduced when OAP particles were combined with other conventional LCMs by a synergistic effect.
RESUMEN
OBJECTIVE: To investigate of the value of monitoring of saturation of blood oxygen of the injured extremity on prevention of osteofascial compartmental syndrome. METHODS: Twenty patients of osteofascial compartmental syndrome included 13 male and 7 female with an average age of 32 years ranging from 13 to 60. There were 13 cases of tibial and fibual fractures, 3 cases of tibial plateau fractures, 4 cases of femoral shaft fractures. SpO2 on the end of injured extremities were dynamic monitored and osteofascial compartmental pressure was measured by modified Whiteside method. The data of two group were compared. RESULTS: Among 20 cases, it's negative correlation between the data of pulse blood oxygen saturation and osteofascial compartmental pressure. CONCLUSION: The method of dynamic monitor extremity SpO2 can reflect indirectly the ischemia in muscle and nerve and report the early diagnosis and management of osteofascial compartmental syndrome.