摘要
目前对于无隔水管钻井液回收(RMR)系统环空压力的研究大多基于浅表层钻井情况,未考虑温度变化所造成的影响。为了探究RMR系统在深海中的温度变化对环空压力的影响,根据RMR系统的双梯度原理和钻井液在环空中的热交换特性,提出当量循环密度(ECD)和环空压力的计算方法,建立了环空内温度场的数学模型,利用计算流体力学软件模拟了某些井段环空中温度场的变化规律。在获得了环空温度变化曲线的前提下,结合实例分析了海水深度、当量循环静态密度(ESD)、岩屑质量分数和排量对RMR系统中环空压力与ECD的影响。研究结果表明:随着海水深度、岩屑质量分数和排量的增加,ECD和环空压力增大;ESD对环空压力的影响实际是温差和压差变化共同作用的结果,而压差对RMR系统中环空压力的影响要大于温差的影响。所得结论对研究RMR系统环空压力的变化具有一定的指导意义。
To find out the influence of temperature change of RMR system on annulus pressure in deep sea,the calculation method of equivalent circulating density(ECD)and annulus pressure is proposed,the mathematical model of temperature field in annulus is established according to the double gradient principle of RMR system and heat exchange characteristics of drilling fluid in the annulus,and change rule of temperature field in the annulus of some well sections is simulated by using computational fluid dynamics software.Based on the actual data,the influence of annulus temperature curve,the influence of seawater depth,equivalent cyclic static density(ESD),cuttings mass fraction and displacement on the annulus pressure and ECD in RMR system are analyzed.The results show that:with the increase of seawater depth,cuttings mass fraction and displacement,ECD and annulus pressure increase;the effect of ESD on annulus pressure is actually the result of temperature difference and pressure difference,and the influence of pressure difference on annulus pressure in RMR system is greater than that of temperature difference.The conclusion has a certain guiding significance for studying the variety of annular pressure in RMR system.
作者
张杰
毛葛振
李鑫
孙学峰
Zhang Jie;Mao Gezhen;Li Xin;Sun Xuefeng(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University)
出处
《石油机械》
北大核心
2020年第12期60-66,共7页
China Petroleum Machinery
基金
国家自然科学基金面上项目“环空气液两相流中气泡微观动态特性研究”(51274168)
国家重点研发计划项目“无隔水管海底泵举升双梯度钻井系统技术及工艺”(2018YFC0310200)。
