水基钻井液低温流变特性研究

深水钻井是中国石油近期和未来发展的必然趋势。温度对钻井液流变性能影响显著，深水低温给钻井液流变性调控带来了巨大挑战。分析了国外深水低温对钻井液流变性影响规律研究现状，利用自行研制的深水低温钻井液基本性能测试模拟实验装置和FANNIX77流变仪，研究了温度和压力对不同水基钻井液体系黏度和动切力的影响。结果表明，温度对不同钻井液体系的黏度影响规律基本相同，即随温度降低黏度增大，从高温到室温钻井液黏度增加比较缓慢，而从室温开始随温度降低黏度迅速升高；温度对含固相钻井液和无固相钻井液体系动切力的影响规律不同，无固相钻井液体系的动切力随温度降低而降低，而含固相钻井液动切力则随温度降低而增加；压力对水基钻井液体系黏度、动切力影响不大。研究结果为我国深水钻井实践提供了室内研究基础。

Study on rheology of water-based drilling fluids under low temperature

Deepwater drilling would be an inevitable tendency in China recently and in future. The low temperature in deepwater formations can seriously influence the rheology of deepwater drilling fluids, and makes a big challenge to rheology control of drilling fluids. The oversea present research situation of drilling fluids’ rheology affected by temperature was analyzed. The impact of temperature and pressure on viscosity and shearing force of different water-based drilling fluids was researched, using a new self-developed deepwater drilling fluids fundamentality performances simulating equipment and FANNIX77 rheometre, which provided a laboratory research base for deepwater drilling in China. The results indicated that temperature has a similar influence on viscosities of different drilling fluids, which increases with temperature declining. It increases slowly when the temperature declining from high to room temperature, but changes swiftly when the temperature is lower than room temperature. There is a different influence on shearing forces by temperature for solid-content and non-solid drilling fluids. The shearing force of the non-solid drilling fluid decreases with the temperature declining, but the solid-content drilling fluid increases. Pressure has almost no influence on viscosities and shearing forces of water-based drilling fluids.