垂直井筒压裂温度场分布理论和计算方法研究

水力压裂施工过程中,随着温度的升高,压裂液粘度降低,影响压裂液的携砂能力。因此,精确计算压裂液在井筒的温度分布极为重要。本文在一定假设条件下,依据热力学平衡方程,考虑压裂液在井筒的摩擦产生的内热,建立了井筒内压裂液和地层温度场热力学平衡解析方程,并且根据数值计算理论,建立离散模型,最后进行了实例计算和分析。结果表明,摩擦产生的热对于计算压裂液温度不可忽略。

Theory and Calculation Method Study of Fracturing Temperature Distribution in Vertical Well-bore

During the process of hydraulic fracturing, the prop-carrying capacity of fracturing fluid will be affected by its decreasing viscosity with temperature increasing. Therefore, it is distinctly important to accurately calculate the temperature distribution of fracturing fluid in well-bore. Based on certain assumptions, according to thermal balance equations and considering the internal heat caused by friction of fracturing fluid, thermal balance equations in well-bore and formation are established in the paper. Meanwhile based on numerical calculation theory, the discrete calculation model is also established and calculation and analysis of examples are made using this model as well. The results show that the heat caused by friction cannot be ignored for the calculation of fracturing fluid temperature.