Evaluation and optimization of cementing slurry system for multicycle injection-production of heavy oil
During the development process of multicycle injection and production of heavy oil,the wellbore cement ring should withstand 350℃high-temperature and multicycle temperature crossing,and the cementing slurry system needs to have good high-temperature resistance and fatigue resistance.Four high-temperature resistant cementing slurry systems are developed and subjected to 10 cycles of heating at 350℃.The compressive strength and elastic modulus of the four cementing slurry systems are measured,and samples are taken for X-ray diffraction analysis,scanning electron microscopy morphology analysis,and nano CT scanning testing.The high-temperature cycling resistance of four cement slurry systems is evaluated and the mechanism of their performance changes is explored.The experimental results show that composite sand cement and high-temperature resistant toughness cement can meet the needs of multicycle injection-production development of heavy oil.The addition of fine silicon powder and elastoplastic agent to portland cement can effectively improve its high-temperature resistance and fatigue resistance.
heavy oil thermal recoverycementinghigh-temperature cycleportland cement