Laboratory Test Study On Weight Loss Of Cement Slurry Considering Formation Condition

With the domestic and international oil and gas exploration and development of oil and gas wells increases quickly, more and more deep, deep well structure more and more complicated, the problem of gasflown become more and more prominent. Once the occurrence of gas flown, will cause a large number of oil and gas resources waste, reduce oil production and recovery factor and environmental pollution, and even cause uncontrolled blowout, at the same time, gas channeling during the repair cost is very high, many because of annular gas channeling in pressure problem can not be solved very well. In this paper, the important impact factors of gas channeling cement slurry weightlessness proceed test research, trying to prevent the annular flow play a guiding role.According to the research contents of this paper making simple weight loss measurement device, the device is convenient to disassemble. The device and the weight loss measurement device using the influence factors on the cement slurry weightlessness (eccentricity, annulus, deviation angle, temperature, slurry column on the dehydration performance difference and cement slurry) experiment. In addition, the gelling properties of cement pastes, the eccentricity is greater than0, the experimental study of cement slurry weight loss of different clearance at the same wellbore.Research shows that:the loss of cement slurry, hole angle cosine value and the induction period of pressure into a linear relationship; the induction period of pressure, temperature and the eccentricity of a certain relationship; the pressure drop rate and the degree of eccentricity, inclination and the temperature difference has a certain relationship; the pressure drop across the same level in the same borehole surface without the same clearance is not the same. Three stages of weight loss curve of cement slurry through morphological changes during the hydration of C3S was explained. According to the gel suspension mechanism of the same wellbore annulus at different pressure drop is discussed in mathematical explanation and analysis. The gel strength of less than50PA, according to the calculation formula of the approaching degree is higher than70%and the experimental values.