耦合钻井液温度特性的地热井井筒温度的数值模拟与分析

发布时间：2018-01-03 17:12

本文关键词：耦合钻井液温度特性的地热井井筒温度的数值模拟与分析　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：地热能是一种绿色、高效、储量巨大、可再生的新能源,具有广阔的发展前景。地热能的开发与利用离不开钻井工作,地热井的地层温度高,影响了钻井液的性能,而钻井液的特性决定井筒温度;另外,地热井往往存在多个地温梯度,本文耦合钻井液温度特性、计算时考虑了多个地温梯度的影响模拟分析了地热井井筒温度,对准确计算井筒温度具有重要意义。取得的成果如下:1.建立了钻井液循环状态下井筒传热模型。根据能量守恒定理和传热学基本原理并结合井筒内的实际情况建立了钻井液循环状态下井筒稳态传热模型和非稳态传热模型并对模型进行求解。2.研究了钻井液的温度特性。研究了温度对钻井液密度、流速、比热容、导热系数和粘度的影响。3.评价了钻井液循环状态下井筒传热模型的准确性。评价了钻井液循环状态下稳态传热模型、钻井液性能恒定和耦合钻井液温度特性的非稳态传热模型的准确性,得出对于所研究的井筒,稳态传热模型、钻井液性能恒定和耦合钻井液温度特性的非稳态传热模型均具有良好的准确性,但耦合钻井液温度特性的非稳态传热模型的精确度最高。4.应用了耦合钻井液温度特性的非稳态传热模型。将耦合钻井液温度特性的非稳态传热模型应用于羊易ZK212和青海贵德ZR1地热井井筒温度研究,计算时考虑了多个地温梯度的影响,模型具有良好的适用性。5.分析了参数敏感性。分别改变地温梯度、钻井液体积流量、入口温度、循环时间、环空间隙、钻井液密度、钻井液比热容、钻井液导热系数和钻井液粘度,重新计算羊易ZK212地热井井筒温度并将计算结果与改变前对比,分析了上述参数对羊易ZK212地热井井筒温度的影响,然后将本文参数敏感性分析所得结论与前人文章中结论进行对比分析。
[Abstract]:Geothermal energy is a green, efficient, huge reserves, renewable new energy, has a broad development prospects. The development and utilization of geothermal energy can not be separated from drilling work, the formation temperature of geothermal wells is high. The performance of drilling fluid is affected, and the wellbore temperature is determined by the characteristics of drilling fluid. In addition, there are many geothermal gradients in geothermal wells. In this paper, the temperature characteristics of drilling fluid are coupled and the influence of multiple geothermal gradients is taken into account in the calculation, and the wellbore temperature of geothermal wells is simulated and analyzed. It is of great significance for accurate calculation of wellbore temperature. The results obtained are as follows:. 1. The wellbore heat transfer model under the condition of drilling fluid circulation is established. According to the energy conservation theorem and the basic principles of heat transfer and the actual situation in the wellbore, the wellbore steady state heat transfer model and the unsteady state are established under the condition of drilling fluid circulation. The temperature characteristics of drilling fluid and the effect of temperature on the density of drilling fluid are studied. The influence of flow rate, specific heat capacity, heat conductivity and viscosity. 3. The accuracy of wellbore heat transfer model under drilling fluid circulation state and steady state heat transfer model under drilling fluid circulation state are evaluated. The accuracy of the unsteady heat transfer model with constant drilling fluid performance and coupled drilling fluid temperature characteristics, the steady-state heat transfer model is obtained for the wellbore studied. The unsteady heat transfer model with constant drilling fluid performance and coupled drilling fluid temperature characteristics has good accuracy. However, the unsteady heat transfer model of coupled drilling fluid temperature characteristics is the most accurate. 4. The unsteady heat transfer model of coupled drilling fluid temperature characteristic is applied to Yangyang heat transfer model. Study on wellbore temperature of geothermal wells in Yi ZK212 and ZR1, Guide, Qinghai Province. The model has good applicability. 5. Analysis of the sensitivity of parameters. Change the geothermal gradient, drilling fluid volume flow, inlet temperature, cycle time, annulus clearance. Drilling fluid density, specific heat capacity of drilling fluid, heat conductivity of drilling fluid and viscosity of drilling fluid are calculated again and the calculated results are compared with those before change. The influence of the above parameters on the wellbore temperature of Yangyi ZK212 geothermal well is analyzed.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P314

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