Study On Water Drive Development Characteristics Based On The Oil-water Two Phase Flow Of Ultra-high Water Cut Stage

Currently, most onshore fields in China have been got into high water cut stage even ultra-high water cut stage. It is significant to study oil-water two-phase water flooding characteristics in ultra-high water cut stage to maintain high and stable oil production. In this paper, we studied the oil-water two-phase flow characteristics, methods of reservoir engineering, the development of dynamic characteristics of indicators and methods to enhance water flooding recovery in the ultra-high water cut stage of oil field. This study reveals the law of oil field development in the extra-high water cut stage which is different from the high water cut stage, analyzes the impact of the dynamic conditions of oil displacement efficiency and relative permeability, improves the data processing method of oil-water two-phase permeability and proposes a new method related to permeability ratio in ultra-high water cut stage. What’s more, this study updates the reservoir engineering methods which probably be used to guide the oil field development in ultra-high water cut stage, and proposes some recommendations in main technical directions of EOR in the ultra-high water cut stage. The results obtained in the paper lay a base for the effective and sustained development of oil field, and enrich the theory of oil field developmentThe main contents are as follows:1. Carry out the study of oil-water two-phase flow characteristics in the ultra-high water cut stage Contrast advantages and disadvantages of existing indoor oil-water two-phase test methods and improve these two methods, analyze the oil-water two-phase flow characteristics of ultra-high water cut stage from two aspects--relative permeability curve characteristics and relative permeability curves influencing factors.2. Improve reservoir engineering methods of ultra-high water cut stage Present the relative permeability mathematical characterization of ultra-high water cut stage, and improve reservoir engineering methods, such as the sub-flow curve, water drive characteristic curve, well spacing density and so on.3. Carry out the study of dynamic index features in the ultra-high water cut stage Analyze the characteristics and influencing factors of production decline, water cut, liquid-producing capacity, and single well controlled recoverable reserves.4. Start the EOR study in the ultra-high water cut stage Analysis the characteristics and influencing factors of water displacement efficiency, understand the limited water oil displacement efficiency and carry out studies on methods, techniques and the development direction to improve oil recovery.