Mechanism and application of synergistic development technology of drag reduction， imbibition， and displacement

Abstract

The low-permeability reservoir is one of the important oil production positions in Shengli Oilfield， and its reserves accounts for more than 20% of the total oilfield reserves. The low-permeability reservoir always presents characteristics such as a narrow pore throat and strong heterogeneity， which results in high injection pressure and difficult injection during water flooding. At present， the main measures to improve the development effect include active agents for reducing pressure and increasing injection， water injection under high pressure， and narrowing the distance of drainage wells. However， there are still some production problems， such as short effective time， low well injection per well， low liquid production per well， and small swept volume. Therefore， it is urgent to develop new and efficient development methods. Since the “13th Five-Year Plan in 2016-2020”， the synergistic development modes have been implemented， such as replenishing energy injection enhancement in injectors， increasing production by imbibition in producers， and increasing swept volume by displacement between injectors and producers， which can enhance displacement pressure gradient， water displacement， and recovery. The synergistic development mode has been applied in Chunhua Oilfield. The injection pressure of the well in 62 Block of Chunhua Oilfield has been reduced by 20%； the water injection has been increased by 25%， and the daily oil production of the single production well has increased from 0.45 t/d to 5.08 t/d， with obvious yield increase benefit. The overall recovery has increased by more than 8%.

Keywords

• drag reduction
• imbibition
• displacement
• synergy
• low-permeability reservoir
• mechanism and application