Status and Prospect of Improved Oil Recovery Technology of High Water Cut Reservoirs

Abstract

The high water cut stage is an important stage of the water injection development of oilfields because there are still more oil reserves available for recovery in this stage. Most oilfields have experienced decades of waterflooding development and adjustment. Although waterflooding reservoirs face the problems of the seriously watered-out and highly dispersed distribution of remaining oil, they remain dominant in waterflood development. This paper investigates the current situation of high-water content reservoirs and the methods available to improve oil recovery and elaborates on the fine reservoir description. Furthermore, it analyzes the main technical measures taken during the high water cut period, namely, secondary oil recovery waterflooding technology (including layer system subdivision, well pattern infilling, strengthening of water injection and liquid extraction, closure of high water cut wells, cyclic waterflooding technology, and water injection profile control) and tertiary oil recovery technology (represented by chemical flooding and gas flooding). In addition, this study reveals the mechanisms and effects of these methods on improving waterflooding development. Finally, this paper summarizes improved oil recovery technology and discusses the key directions and development prospects of this technology in enhancing the oil recovery rate.

Modeling and Adoption of Technological Solutions in Order to Enhance the Effectiveness of Measures to Limit Water Inflows into Oil Wells under Conditions of Uncertainty

“…After the successful completion of the investigation, nine additional high-water cut wells were ceased. High economic indicators were attained, and oil production was increased under conditions of continuous water injection and fluid generation [10]. It is noted that various technologies of cyclic waterflooding are constantly being developed in the field [9].…”

“…The computation results of the weight contributions are shown in Table 3. Calculations were performed using Equation (10).…”

Design of Janus Nanoparticles for Mobility Control in Heterogeneous Reservoirs

“…With the deepening development of reservoirs, oil fields are entering a high-water-cut phase, marked by significant changes in reservoir heterogeneity and a notable decline in well productivity . Prolonged water injection has notably altered the macro and microstructure of reservoir rocks, exacerbating water channeling phenomena in high-permeability layers and large pores, thereby diminishing water-flooding recovery rates. , Therefore, employing advanced techniques is crucial to boosting recovery rates and significantly increasing oil field productivity.…”

“… 1 Prolonged water injection has notably altered the macro and microstructure of reservoir rocks, exacerbating water channeling phenomena in high-permeability layers and large pores, thereby diminishing water-flooding recovery rates. 2 , 3 Therefore, employing advanced techniques is crucial to boosting recovery rates and significantly increasing oil field productivity.…”

The Mechanism Study of Fracture Porosity in High-Water-Cut Reservoirs

“…At present, the identification methods of large pores can be divided into four categories: inter-well tracer monitoring method, well test method, logging data interpretation method, and reservoir engineering synthesis method [29][30][31]. Inter-well tracer monitoring method is to inject tracer from the well, then monitor whether the produced liquid contains tracer, and draw a curve according to the tracer production concentration and time and use the result curve given by the tracer to analyze the underground reservoir parameters more carefully.…”