基于均质油藏水驱油物理模拟实验,研究不同黏度均质油藏在不同采油速度下的水驱特征。低黏度油藏（黏度小于5 m Pa·s）水驱波及均匀,流线粗。随采油速度的提高,注水沿油层底部突进减弱,纵向波及更均匀,油层顶、底面波及系数差异减...基于均质油藏水驱油物理模拟实验,研究不同黏度均质油藏在不同采油速度下的水驱特征。低黏度油藏（黏度小于5 m Pa·s）水驱波及均匀,流线粗。随采油速度的提高,注水沿油层底部突进减弱,纵向波及更均匀,油层顶、底面波及系数差异减小。低黏度油藏高速开发无水期采出程度明显高于低速开发,含水上升速度低于低速开发,适宜高速开发模式。中高黏度油藏（黏度5~50 m Pa·s）水驱过程中注入水表现出明显的指进现象,水驱流线细,水驱波及不完全,流线间波及程度弱,油层顶、底面波及系数差异大。随采油速度的提高,中高黏度油藏水驱流线更细,波及更不完全,油层顶、底面波及系数明显降低。中高黏度油藏高速开发见水时间短,无水期采出程度明显低于低速开发,含水上升速度高于低速开发,不适合高速开发。展开更多
The similarity criterion for water flooding reservoir flows is concerned with in the present paper. When finding out all the dimensionless variables governing this kind of flow, their physical meanings are subsequentl...The similarity criterion for water flooding reservoir flows is concerned with in the present paper. When finding out all the dimensionless variables governing this kind of flow, their physical meanings are subsequently elucidated. Then, a numerical approach of sensitivity analysis is adopted to quantify their corresponding dominance degree among the similarity parameters. In this way, we may finally identify major scaling law in different parameter range and demonstrate the respective effects of viscosity, permeability and injection rate.展开更多
To explore the method of improving development effect and solving the problem of water breakthrough and water out for ultralow permeability fractured reservoirs, an indoor evaluation method of dynamic imbibition for f...To explore the method of improving development effect and solving the problem of water breakthrough and water out for ultralow permeability fractured reservoirs, an indoor evaluation method of dynamic imbibition for fracture-matrix system was established taking the Chang 8 reservoir in southern Yanchang Oilfield as a research target. Key factors for the imbibition effect were obtained, an imbibition's rate expression was obtained, a model considering the double effects of imbibition-displacement was built and optimal injection and production parameters for the research area were obtained as well. The results show that an optimum displacement rate that maximizes the oil displacement efficiency exists in the water displacing oil process, and the optimal displacing rate becomes smaller as the permeability decreases. The imbibition displacement efficiency increases as the reservoir quality index and water wettability index of rock become bigger. But the larger the initial water saturation or oil-water viscosity ratio is, the smaller the imbibition displacement efficiency is. The optimal injection-production ratio for the Chang 8 reservoir of southern Yanchang Oilfield is 0.95, and the predicted recovery is 17.2% when the water cut is 95%, it is 2.9% higher than the recovery of conventional injection-production ratio 1.2. By using the moderate water injection technique based on the double effects of imbibition-displacement mechanism, the water injection development effect for the ultra-low permeability fractured reservoirs can be improved significantly.展开更多
文摘基于均质油藏水驱油物理模拟实验,研究不同黏度均质油藏在不同采油速度下的水驱特征。低黏度油藏（黏度小于5 m Pa·s）水驱波及均匀,流线粗。随采油速度的提高,注水沿油层底部突进减弱,纵向波及更均匀,油层顶、底面波及系数差异减小。低黏度油藏高速开发无水期采出程度明显高于低速开发,含水上升速度低于低速开发,适宜高速开发模式。中高黏度油藏（黏度5~50 m Pa·s）水驱过程中注入水表现出明显的指进现象,水驱流线细,水驱波及不完全,流线间波及程度弱,油层顶、底面波及系数差异大。随采油速度的提高,中高黏度油藏水驱流线更细,波及更不完全,油层顶、底面波及系数明显降低。中高黏度油藏高速开发见水时间短,无水期采出程度明显低于低速开发,含水上升速度高于低速开发,不适合高速开发。
基金The project supported by the Innovative Project of CAS (KJCX-SW-L08)the National Basic Research Program of China(973)
文摘The similarity criterion for water flooding reservoir flows is concerned with in the present paper. When finding out all the dimensionless variables governing this kind of flow, their physical meanings are subsequently elucidated. Then, a numerical approach of sensitivity analysis is adopted to quantify their corresponding dominance degree among the similarity parameters. In this way, we may finally identify major scaling law in different parameter range and demonstrate the respective effects of viscosity, permeability and injection rate.
基金Supported by Science Coordination New Project(2016KTCL01-12)
文摘To explore the method of improving development effect and solving the problem of water breakthrough and water out for ultralow permeability fractured reservoirs, an indoor evaluation method of dynamic imbibition for fracture-matrix system was established taking the Chang 8 reservoir in southern Yanchang Oilfield as a research target. Key factors for the imbibition effect were obtained, an imbibition's rate expression was obtained, a model considering the double effects of imbibition-displacement was built and optimal injection and production parameters for the research area were obtained as well. The results show that an optimum displacement rate that maximizes the oil displacement efficiency exists in the water displacing oil process, and the optimal displacing rate becomes smaller as the permeability decreases. The imbibition displacement efficiency increases as the reservoir quality index and water wettability index of rock become bigger. But the larger the initial water saturation or oil-water viscosity ratio is, the smaller the imbibition displacement efficiency is. The optimal injection-production ratio for the Chang 8 reservoir of southern Yanchang Oilfield is 0.95, and the predicted recovery is 17.2% when the water cut is 95%, it is 2.9% higher than the recovery of conventional injection-production ratio 1.2. By using the moderate water injection technique based on the double effects of imbibition-displacement mechanism, the water injection development effect for the ultra-low permeability fractured reservoirs can be improved significantly.
