为了研究尾管结构对SAGD注采参数和sub-cool的影响,建立了SAGD水平井生产阶段的物理模型和基本假设,根据本达克利亚方程进行流入动态分析,采用Beggs-Brill方法模拟了不同尾管结构下井筒压力和温度分布,获得了定产量生产的供排协调关系,...为了研究尾管结构对SAGD注采参数和sub-cool的影响,建立了SAGD水平井生产阶段的物理模型和基本假设,根据本达克利亚方程进行流入动态分析,采用Beggs-Brill方法模拟了不同尾管结构下井筒压力和温度分布,获得了定产量生产的供排协调关系,并优化了尾管设计和注采参数。研究结果表明:SAGD井自喷生产井底流压调控难度大,需要下泵举升,下泵举升时,尾管尺寸优选73 mm油管,尾管下深不超过A点后150 m; sub-cool越小,越容易发生泵吸入口闪蒸和水平段汽窜,sub-cool过大影响单井产量,根据现场数据进行井筒温度模拟,sub-cool范围为5~15℃。研究结果能够为SAGD水平井的生产设计提供理论依据。展开更多
As the ultra-heavy oil reservoirs developed by steam assisted gravity drainage(SAGD)in the Fengcheng oilfield,Xinjiang have problems such as huge steam usage,long preheating period,low production,and inaccessible rese...As the ultra-heavy oil reservoirs developed by steam assisted gravity drainage(SAGD)in the Fengcheng oilfield,Xinjiang have problems such as huge steam usage,long preheating period,low production,and inaccessible reserve in local parts.Based on the rock mechanics and porosity/permeability characteristics of heavy oil reservoir and interlayer,a series of true triaxial experiments and CT tests considering the fracturing fluid injection rate,viscosity,perforation density and location of fracture initiation were conducted to disclose the propagation behavior of micro-and macro-fractures in the reservoirs and mudstone interlayers.These experiments show that fracturing in the heavy oil reservoirs only generates microfractures that cannot break the interlayer.In contrast,when fracturing in the interlayer,the higher the injection rate(greater than 0.6 m^3/min),the lower the viscosity,the easier it is to form macro-fractures in the interlayers,and the further the fractures will propagate into the reservoirs.Also,increasing perforation density tends to create complex macro-fracture network in the interbedded reservoirs and mudstone interlayers.The findings of this study can provide scientific guidance for the selection of fracturing layer and the optimization of parameters in the interlayer fracturing of heavy oil reservoirs.展开更多
文摘为了研究尾管结构对SAGD注采参数和sub-cool的影响,建立了SAGD水平井生产阶段的物理模型和基本假设,根据本达克利亚方程进行流入动态分析,采用Beggs-Brill方法模拟了不同尾管结构下井筒压力和温度分布,获得了定产量生产的供排协调关系,并优化了尾管设计和注采参数。研究结果表明:SAGD井自喷生产井底流压调控难度大,需要下泵举升,下泵举升时,尾管尺寸优选73 mm油管,尾管下深不超过A点后150 m; sub-cool越小,越容易发生泵吸入口闪蒸和水平段汽窜,sub-cool过大影响单井产量,根据现场数据进行井筒温度模拟,sub-cool范围为5~15℃。研究结果能够为SAGD水平井的生产设计提供理论依据。
基金Supported by the National Natural Science Foundation of China(51404281)
文摘As the ultra-heavy oil reservoirs developed by steam assisted gravity drainage(SAGD)in the Fengcheng oilfield,Xinjiang have problems such as huge steam usage,long preheating period,low production,and inaccessible reserve in local parts.Based on the rock mechanics and porosity/permeability characteristics of heavy oil reservoir and interlayer,a series of true triaxial experiments and CT tests considering the fracturing fluid injection rate,viscosity,perforation density and location of fracture initiation were conducted to disclose the propagation behavior of micro-and macro-fractures in the reservoirs and mudstone interlayers.These experiments show that fracturing in the heavy oil reservoirs only generates microfractures that cannot break the interlayer.In contrast,when fracturing in the interlayer,the higher the injection rate(greater than 0.6 m^3/min),the lower the viscosity,the easier it is to form macro-fractures in the interlayers,and the further the fractures will propagate into the reservoirs.Also,increasing perforation density tends to create complex macro-fracture network in the interbedded reservoirs and mudstone interlayers.The findings of this study can provide scientific guidance for the selection of fracturing layer and the optimization of parameters in the interlayer fracturing of heavy oil reservoirs.
