莺-琼盆地海洋钻井井筒温度预测与分析

Prediction and Analysis of Wellbore Temperature of Offshore Drilling in Ying-Qiong Basin

莺琼盆地作为南海北部的重要沉积盆地,因其丰富的油气资源和复杂的地质结构,成为了中国能源开发的重点区域之一。在深水超深井勘探中,高温是不可避免的一大难题,由于复杂的地质环境和地温梯度的广泛分布,目前测得地层温度最高已超过240℃,高温则会影响井下工作的安全和效率。因此,通过计算地温梯度和利用流体传热方程建立井筒温度预测模型,有利于分析钻井过程中井底的温度。经过模型计算的结果与实测数据相对比,二者基本吻合,说明了井筒模型预测的可靠性。适当提高钻井液泵排量可以加快钻井液的循环速率,更快的将井底热量带出地表;增加钻井液的循环时间和钻井液密度可有效降低井底温度。

As an important sedimentary basin in the northern part of the South China Sea,Yingqiong Basin has become one of the key areas for Chinas energy development due to its rich oil and gas resources and complex geological structure.In the exploration of deepwater ultra-deep wells,high temperature is an unavoidable problem.Due to the complex geological environment and the wide distribution of the ground temperature gradient,the highest measured formation temperature has already exceeded 240 C,and the high temperature affects the safety and efficiency of downhole work.Therefore,it is beneficial to analyze the temperature of the wellbore during drilling by calculating the ground temperature gradient and using the fluid heat transfer equation to establish a wellbore temperature prediction model.After comparing the results calculated by the model with the measured data,the two basically coincide,indicating the reliability of the wellbore model prediction.Appropriately increasing the drilling fluid pump displacement can speed up the circulation rate of drilling fluid and bring the heat from the bottom of the well to the surface faster;increasing the circulation time of drilling fluid and the density of drilling fluid can effectively reduce the temperature of the bottom of the well.