Abstract
After long-term waterflooding in unconsolidated sandstone reservoir, the high-permeability channels are easy to evolve, which leads to a significant reduction in water flooding efficiency and a poor oilfield development effect. The current researches on the formation parameters variation are mainly based on the experiment analysis or field statistics, while lacking quantitative research of combining microcosmic and macroscopic mechanism. A network model was built after taking the detachment and entrapment mechanisms of particles in unconsolidated sandstone reservoir into consideration. Then a coupled mathematical model for the formation parameters variation was established based on the network modeling and the model of fluids flowing in porous media. The model was solved by a finite-difference method and the Gauss-Seidel iterative technique. A novel field-scale reservoir numerical simulator was written in Fortran 90 and it can be used to predict 1) the evolvement of high-permeability channels caused by particles release and migration in the long-term water flooding process, and 2) well production performances and remaining oil distribution. In addition, a series of oil field examples with inverted nine-spot pattern was made on the new numerical simulator. The results show that the high-permeability channels are more likely to develop along the main streamlines between the injection and production wells, and the formation parameters variation has an obvious influence on the remaining oil distribution.
Highlights
Because of its low expense and high effectiveness, waterflooding is the most popular enhanced oil recovery technique applied in Chinese oil fields, such as Daqing oil field and Shengli oil field
After long-term waterflooding in unconsolidated sandstone reservoir, the high-permeability channels are easy to evolve, which leads to a significant reduction in water flooding efficiency and a poor oilfield development effect
A coupled mathematical model for the formation parameters variation was established based on the network modeling and the model of fluids flowing in porous media
Summary
Because of its low expense and high effectiveness, waterflooding is the most popular enhanced oil recovery technique applied in Chinese oil fields, such as Daqing oil field and Shengli oil field. Water is injected into the formation via the injection wells continually and the injected water will make great impacts on the formation parameters, such as permeability, porosity, content of clay minerals and contact pattern of skeleton particles These impacts could be of great importance for the distribution of the remaining oil and development of the oil fields (Han, 2010; Shokri & Babadagli, 2016). For its advantages of low expense and dynamic prediction, reservoir simulation is quite a significant technique used during the long period of reservoir development It is quite useful for the study of the remaining oil distribution (Rege & Fogler, 1987; Jiang et al, 2005; Cui et al, 2012; Feng et al, 2009; Crandell et al, 2012; Feng & Bai, 2011). The reservoir permeability variation and its influence on the remaining oil distribution are analyzed
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
