气井井筒瞬态温度压力耦合模型研究
发布时间：2018-07-21 19:56
【摘要】：天然气气藏在我国分布广泛。实现气藏的高效开发,应做好对气藏的动态监测,最基础的是对单井井筒压力、温度数据的监测。获得数据的方法有两种：一是下井下压力计、温度计实测压力温度分布；二是通过井口数据和产出流体性质等相关数据,通过井筒温度压力模型来计算井筒温度、压力分布。目前许多复杂井况的气井难以下入测试仪器进行监测,只能通过第二种方法获得井底数据。而传统的稳态井筒温度压力模型难以解决复杂问题,因此需要展开对井筒瞬态温度压力模型的研究。 本文对气井生产过程中的井筒温度和压力随时间的变化问题开展了相关研究,主要开展了以下工作：从传热学和热力学相关参数介绍出发,介绍了固体、流体、固体与流体间的热物性参数；通过对原有井筒瞬态传热模型进行分析,指出其在模型假设条件上处理的不当之处,并建立了更贴近真实井筒传热过程的“井筒-地层瞬态传热模型”,并结合井筒流体能量守恒方程推导了井筒瞬态温度模型；介绍了常用井筒单相管流压力模型,并对井筒两相管流压力模型进行了改进与优选；将所建立的井筒瞬态温度模型与优选的井筒压力模型进行耦合,并通过程序实现其功能,在此基础上,进行了对比验证、敏感性分析和实例应用等相关研究,得到了以下结论和认识： (1)热物性参数沿井深变化显著,不能简单考虑为定值。 (2)传统的井筒温度模型假设条件存在不足——这类模型将井筒传热考虑为稳态传热,由此建立的井筒-地层瞬态传热模型可以克服该缺陷。 (3)热量在井筒-地层中的传递存在5个典型阶段,分别为：初期阶段、热量在井筒内做稳定径向导热阶段、热量从井筒向地层过渡阶段、热量在地层内做径向导热阶段以及反应外边界条件阶段,且敏感性分析表明无量纲距离、无量纲导热系数和无量纲单位体积热容对井筒-地层瞬态传热有一定的影响。 (4)不管是采用152组测压数据还是气液比小于2000m3/m3的测压数据做两相管流模型评价,改进的HasanKabir模型均具有较高的计算精度。从模型理论基础与计算精度两者看来,推荐采用HasanKabir模型进行两相管流压降计算。 (5)开展了模型对比验证和实例分析,得到以下认识：①采用PIPESIM、COMSOL软件进行相关计算,与本模型计算结果吻合程度高,②不耦合温度下的压力计算和不耦合压力下的温度计算值与耦合模型相比误差较大,③常用的Ramey模型和HasanKabir模型计算精度欠缺,④产气量、产水量、流体比热、水泥环导热系数对井筒温度剖面影响很大；环空流体自然对流换热系数对其有一定影响；地层岩石导热系数、流体导热系数、油管流体强制对流换热系数和环空辐射传热系数对其几乎没有影响,同时产气量、产水量对井筒压力剖面影响较大,其余参数对其影响相对有限,⑤提供了一种通过本模型来解决高温高压气井产能测试过程中不稳定条件下解决问题的方法。
[Abstract]:Natural gas reservoirs are widely distributed in our country . In order to realize the efficient development of gas reservoirs , the dynamic monitoring of gas reservoirs should be done well , and the monitoring of the pressure and temperature data of single well bores is the most basic . There are two methods for obtaining the data : one is the downhole pressure gauge , the temperature distribution of the measured pressure of the thermometer ;
The wellbore temperature and pressure distribution are calculated by wellbore temperature pressure model , which is difficult to solve complex problems . Therefore , it is necessary to study the transient temperature pressure model of wellbore .
In this paper , the problems of wellbore temperature and pressure over time during the production of gas wells are studied . The following tasks are mainly carried out : the thermal physical property parameters of solids , fluids , solids and fluids are introduced from the introduction of heat transfer and thermodynamics related parameters ;
Through the analysis of the transient heat transfer model of the existing wellbore , it is pointed out that it is not the same as that of the model hypothesis , and establishes a " wellbore - formation transient heat transfer model " that is closer to the real wellbore heat transfer process , and derives the transient temperature model of the wellbore in combination with the wellbore fluid energy conservation equation ;
This paper introduces the common wellbore single - phase pipe flow pressure model , and improves and optimizes the two - phase flow pressure model of wellbore .
The established wellbore transient temperature model is coupled with the preferred wellbore pressure model , and its function is realized through program . On the basis of this , the following conclusions and understandings are obtained :
( 1 ) The thermal property parameters vary significantly along the well depth , which cannot be simply considered as fixed value .
( 2 ) The traditional wellbore temperature model assumes that the condition exists under the condition that the wellbore heat transfer is considered to be a steady state heat transfer , and the established wellbore - formation transient heat transfer model can overcome the defect .
( 3 ) There are five typical stages in the transfer of heat in the wellbore - formation . In the initial stage , the heat is stable radial heat conduction stage in the well bore . The heat is transferred from the wellbore to the formation transitional stage . The heat is in the formation of the radial heat conduction stage and the outer boundary condition stage of the reaction , and the sensitivity analysis shows that the dimensionless distance , dimensionless heat conductivity coefficient and dimensionless unit volume heat capacity have a certain influence on the wellbore - formation transient heat transfer .
( 4 ) The improved HasanKabir model has higher computational accuracy , whether by using 152 sets of pressure measurement data or gas - liquid ratio less than 2000m3 / m3 , and the HasanKabir model is recommended to calculate the pressure drop of two - phase tube from both the theoretical basis and calculation precision of the model .
( 5 ) The model contrast verification and the case analysis are carried out to get the following understanding : ( 1 ) Using the PIPESIM and COMSOL software for correlation calculation , the calculation results agree well with the calculation results of this model , 鈶，
本文编号：2136690
[Abstract]:Natural gas reservoirs are widely distributed in our country . In order to realize the efficient development of gas reservoirs , the dynamic monitoring of gas reservoirs should be done well , and the monitoring of the pressure and temperature data of single well bores is the most basic . There are two methods for obtaining the data : one is the downhole pressure gauge , the temperature distribution of the measured pressure of the thermometer ;
The wellbore temperature and pressure distribution are calculated by wellbore temperature pressure model , which is difficult to solve complex problems . Therefore , it is necessary to study the transient temperature pressure model of wellbore .
In this paper , the problems of wellbore temperature and pressure over time during the production of gas wells are studied . The following tasks are mainly carried out : the thermal physical property parameters of solids , fluids , solids and fluids are introduced from the introduction of heat transfer and thermodynamics related parameters ;
Through the analysis of the transient heat transfer model of the existing wellbore , it is pointed out that it is not the same as that of the model hypothesis , and establishes a " wellbore - formation transient heat transfer model " that is closer to the real wellbore heat transfer process , and derives the transient temperature model of the wellbore in combination with the wellbore fluid energy conservation equation ;
This paper introduces the common wellbore single - phase pipe flow pressure model , and improves and optimizes the two - phase flow pressure model of wellbore .
The established wellbore transient temperature model is coupled with the preferred wellbore pressure model , and its function is realized through program . On the basis of this , the following conclusions and understandings are obtained :
( 1 ) The thermal property parameters vary significantly along the well depth , which cannot be simply considered as fixed value .
( 2 ) The traditional wellbore temperature model assumes that the condition exists under the condition that the wellbore heat transfer is considered to be a steady state heat transfer , and the established wellbore - formation transient heat transfer model can overcome the defect .
( 3 ) There are five typical stages in the transfer of heat in the wellbore - formation . In the initial stage , the heat is stable radial heat conduction stage in the well bore . The heat is transferred from the wellbore to the formation transitional stage . The heat is in the formation of the radial heat conduction stage and the outer boundary condition stage of the reaction , and the sensitivity analysis shows that the dimensionless distance , dimensionless heat conductivity coefficient and dimensionless unit volume heat capacity have a certain influence on the wellbore - formation transient heat transfer .
( 4 ) The improved HasanKabir model has higher computational accuracy , whether by using 152 sets of pressure measurement data or gas - liquid ratio less than 2000m3 / m3 , and the HasanKabir model is recommended to calculate the pressure drop of two - phase tube from both the theoretical basis and calculation precision of the model .
( 5 ) The model contrast verification and the case analysis are carried out to get the following understanding : ( 1 ) Using the PIPESIM and COMSOL software for correlation calculation , the calculation results agree well with the calculation results of this model , 鈶，
本文编号：2136690
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