A large amount of residue from the water treatment process has gradually accumulated and thus caused serious environmental pollution in waterflood oilfields. The water treatment residue is a grey suspension, with a de...A large amount of residue from the water treatment process has gradually accumulated and thus caused serious environmental pollution in waterflood oilfields. The water treatment residue is a grey suspension, with a density of 1.08 g/cm^3, and mainly contains over 65% of light CaCO3, MgCO3, CaSO4, Fe2S3 and Ca（OH）2. This paper ascertains the effect of water treatment residue on core permeability and its application in oilfields. Coreflooding tests in laboratory were conducted in two artificial cores and one natural core. Core changes were evaluated by cast model image analysis, mercury injection method and scanning electron microscopy （SEM）. Fresh water was injected into another natural core, which was plugged with water treatment residue, to determine the effective life. The results indicate that the water treatment residue has a strongly plugging capability, a resistance to erosion and a long effective life, and thus it can be used as a cheap raw material for profile control. In the past 8 years, a total of 60,164 m^3 of water treatment residue has been used for profile control of 151 well treatments, with a success ratio of 98% and an effective ratio of 83.2%. In the field tests, the profile control agent increased both starting pressure and injection pressure of injectors, and decreased the apparent water injectivity coefficient, significantly improving intake profiles and lengthening average service life of injectors. 28,381 tons of additional oil were recovered from these corresponding oil wells, with economic benefits of ￥3,069.55×10^4 （RMB） and a remarkable input-output ratio of 8.6：1.展开更多
颗粒调剖堵水是提高原油采收率的重要途径。了解颗粒在多孔介质中的运移沉积特性,便于颗粒制备的优化,提高颗粒与地层孔喉配伍性和封堵效率。综述了颗粒浓度值、粒径、多孔介质结构、粒径比、介质内流体参数等因素对运移沉积的影响,总...颗粒调剖堵水是提高原油采收率的重要途径。了解颗粒在多孔介质中的运移沉积特性,便于颗粒制备的优化,提高颗粒与地层孔喉配伍性和封堵效率。综述了颗粒浓度值、粒径、多孔介质结构、粒径比、介质内流体参数等因素对运移沉积的影响,总结了简化几何、介观模拟、LB-DEM(lattice Boltzmann method-discrete element method)、CFD-DEM(computational fluid dynamics-discrete element method)等模拟方法研究结果。分析表明,粒径比的临界值影响多孔介质的沉积位置和堵塞程度,粒径不同、所受力差异较大,大颗粒受水动力、重力、流体流速影响显著。多孔介质内流体流动模型尚未完全统一,Brinkman-Forchheimer-Darcy模型适用性较强,CFD-DEM方法从微观角度对介质内运移沉积流固耦合进行了验证,为非均质储层的调剖方案提供了依据。展开更多
文摘A large amount of residue from the water treatment process has gradually accumulated and thus caused serious environmental pollution in waterflood oilfields. The water treatment residue is a grey suspension, with a density of 1.08 g/cm^3, and mainly contains over 65% of light CaCO3, MgCO3, CaSO4, Fe2S3 and Ca（OH）2. This paper ascertains the effect of water treatment residue on core permeability and its application in oilfields. Coreflooding tests in laboratory were conducted in two artificial cores and one natural core. Core changes were evaluated by cast model image analysis, mercury injection method and scanning electron microscopy （SEM）. Fresh water was injected into another natural core, which was plugged with water treatment residue, to determine the effective life. The results indicate that the water treatment residue has a strongly plugging capability, a resistance to erosion and a long effective life, and thus it can be used as a cheap raw material for profile control. In the past 8 years, a total of 60,164 m^3 of water treatment residue has been used for profile control of 151 well treatments, with a success ratio of 98% and an effective ratio of 83.2%. In the field tests, the profile control agent increased both starting pressure and injection pressure of injectors, and decreased the apparent water injectivity coefficient, significantly improving intake profiles and lengthening average service life of injectors. 28,381 tons of additional oil were recovered from these corresponding oil wells, with economic benefits of ￥3,069.55×10^4 （RMB） and a remarkable input-output ratio of 8.6：1.
文摘颗粒调剖堵水是提高原油采收率的重要途径。了解颗粒在多孔介质中的运移沉积特性,便于颗粒制备的优化,提高颗粒与地层孔喉配伍性和封堵效率。综述了颗粒浓度值、粒径、多孔介质结构、粒径比、介质内流体参数等因素对运移沉积的影响,总结了简化几何、介观模拟、LB-DEM(lattice Boltzmann method-discrete element method)、CFD-DEM(computational fluid dynamics-discrete element method)等模拟方法研究结果。分析表明,粒径比的临界值影响多孔介质的沉积位置和堵塞程度,粒径不同、所受力差异较大,大颗粒受水动力、重力、流体流速影响显著。多孔介质内流体流动模型尚未完全统一,Brinkman-Forchheimer-Darcy模型适用性较强,CFD-DEM方法从微观角度对介质内运移沉积流固耦合进行了验证,为非均质储层的调剖方案提供了依据。
