储层—井筒—井口一体化动态分析方法研究

发布时间：2018-04-03 01:29

本文选题：低渗气藏　切入点：井筒举升模型　出处：《西南石油大学》2017年硕士论文

【摘要】：苏里格属于致密气藏,气井普遍采用压裂投产,为了维持较高产量,采用了较大的生产压差,因此投产后产量快速递减;投产初期的产量包含了高导流能力压裂缝的供给作用,产量递减趋势中包含了近井带的能量衰竭和地层供给不足;后期的减速递减特征反映了采气强度降低后远井地层的平衡供给能力以及井下节流器不同程度的张开失效带来的增产效应。深入研究气井产量变化规律及优化增产措施对提高气井的产量和优化工程作业环节具有积极的意义。论文以苏里格气田为研究对象,生产套管为3.5寸,投产初期采用压裂投产,早期生产管柱是在带节流器的3.5寸套管内生产。这种生产管柱造成大部分井无油套压数据,为获得这些数据少数井采用了压力监测来得到,气井存在积液现象。进行了低渗气藏的气井生产动态分析。低渗气藏出水原因及特征分析,从气体滑脱效应、高速非达西渗流、启动压力梯度、应力敏感分析了低渗储层气水两相特殊渗流机理。分析了低渗气藏出水产能公式中气相有效渗透率、地层流体平均粘度、气井控制半径等参数的取值及地层出水对气井产能的影响评价。出水气井产量递减分析,产量递减原因及递减类型的地质成因的分析。井筒举升模型,进行了携液临界产量计算原理及实例分析。进行了携液井筒压力损耗计算方法的推导及携液举升能力评价。开展了储层-井筒-井口一体化气井动态分析方法。一体化动态分析思路包括根据地质成因进行产量的分段递减分析、基于地层条件的生产历史拟合和动态预测、综合递减分析评价气井的开发潜力。进行了复合产量递减分析方法的原理、优势、局限、改进、分析步骤分析。进行了递减法生产动态预测的实例计算。结果表明拟合精度有所提高。典型井单井数值模拟调参原则是初期产量变化规律体现了地层的供给速度,通过调整地层渗透率(0.01-2.5mD)来拟合;中后期产量变化体现了地层能量的保持程度,即储量的衰竭程度,通过调整单井控制范围来拟合,根据砂体分布特征,通过调整地质模型的宽度(20-1000m)来实现。数值模拟得到的单井控制储量与测试无阻流量具有较好的一致性。典型井生产历史拟合结果表明拟合度最高97.4%、最低63.0%,平均89.5%;67口井拟合度超过80%,占总井数88.2%,满足设计要求。研究方法及获得的认识对产量递减变化规律、生产历史拟合、动态预测及速度管柱和增压开采优化设计具有一定的指导意义。
[Abstract]:Sulige belongs to the tight gas reservoir. In order to maintain the high production rate, the production pressure difference is adopted in order to maintain the high production rate, so the production decreases rapidly after putting into production, and the initial production of the gas well contains the supply function of the high conductivity energy pressure fracture.The decline trend of production includes the energy exhaustion in the near well zone and the insufficient supply of formation;The characteristics of deceleration decline in the later stage reflect the equilibrium supply capacity of the far well formation after the gas recovery intensity is reduced and the effect of increasing production caused by the failure of downhole throttle opening to varying degrees.It is of great significance to study the variation law of gas well production and optimize the production increase measures for improving the production rate of gas well and optimizing the engineering operation.The paper takes Sulige gas field as the research object, the production casing is 3.5-inch, the initial stage of production is fracturing, the early production string is produced in the 3.5-inch casing with throttle.This kind of production string results in the oil-free casing pressure data of most wells. In order to obtain these data, a few wells are obtained by pressure monitoring, and there is fluid accumulation in gas wells.The production performance of gas wells in low permeability gas reservoirs is analyzed.Based on the analysis of the reasons and characteristics of low permeability gas reservoir effluent, the special seepage mechanism of gas and water two phases in low permeability reservoir is analyzed from gas slip effect, high speed non Darcy seepage flow, starting pressure gradient and stress sensitivity.The effective permeability of gas phase, the average viscosity of formation fluid, the control radius of gas well and the influence of formation water on gas well productivity are analyzed.The analysis of the production decline, the cause of production decline and the geological origin of decline type.The calculation principle of critical output of liquid carrying and the analysis of examples are carried out in the wellbore lifting model.The calculation method of pressure loss in fluid carrying well and the evaluation of lift capacity of liquid carrying are carried out.The reservoir-wellbore-wellhead integrated gas well performance analysis method is developed.The idea of integrated dynamic analysis includes segmental decline analysis of production according to geological origin, production history fitting and dynamic prediction based on formation conditions, and comprehensive decline analysis to evaluate the development potential of gas wells.The principle, advantage, limitation, improvement and analysis procedure of compound production decline analysis method are analyzed.An example calculation of production dynamic prediction by decreasing method is carried out.The results show that the fitting accuracy is improved.The principle of adjusting parameters by numerical simulation of typical wells is that the law of initial production change reflects the supply rate of formation, which is fitted by adjusting formation permeability 0.01-2.5mD. the variation of production in the middle and late stage reflects the degree of formation energy preservation, that is, the degree of depletion of reserves.By adjusting the control range of single well to fit, according to the distribution characteristics of sand body, the width of geological model is adjusted to 20-1000m).The controlled reserves obtained by numerical simulation are in good agreement with the measured unobstructed flow.The fitting results of production history of typical wells show that the fitting degree is the highest 97.4 and the lowest 63.0. The average fitting degree of 69.5and 67 wells exceeds 80, accounting for 88.2 of the total wells, which meets the design requirements.The research method and the knowledge obtained have certain guiding significance to the law of production decline change, production history fitting, dynamic prediction and optimization design of speed pipe string and pressurized mining.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE332

【相似文献】