Abstract
The diamond-shape inverted nine-spot well pattern is widely used in developing low-permeability reservoirs with fractures. However, production wells with equal fracture lengths will lead to nonuniform displacement, especially in anisotropic reservoir. Previous researches mainly focused on equal-length fractures, while studies on the unequal-length fractures which can dramatically improve the development efficiency were little. In this paper, a corresponding numerical model with unequal length of fracture designed in the edge and the corner wells was built in a low-permeability anisotropic reservoir. The main objective was to examine and evaluate the effects of anisotropic permeability and fracture parameter on the waterflooding in the diamond-shape inverted nine-spot well pattern. The results indicate that different fractures penetration ratio and anisotropic permeability both result in different development efficiency. Fracture of the edge well are more easily to be water breakthrough, while the increase of penetration ratio of injection well effectively enhance oil recovery. Moreover, the most optimal penetration ratios of production well fractures under different kx : ky are determined. With the increase of kx : ky, the optimized penetration ratio of corner wells fracture decrease, while that of the edge wells increase. Setting unequal length fractures in low-permeability anisotropic reservoirs can effectively improve the oil displacement efficiency in the waterflooding process.
Highlights
Waterflooding technique is one of the most common methods for enhancing oil recovery in developing oil reservoirs [1]
Different forms of water injection well pattern were used for the development of reservoirs, including five-point method, seven-point method, and nine-point method
The main objective of this paper is to investigate the effect of the anisotropic permeability on the development of waterflood in different fractures parameters of the diamond-shape inverted nine-spot well pattern
Summary
Waterflooding technique is one of the most common methods for enhancing oil recovery in developing oil reservoirs [1]. Well with fractures can increase the amount of water injection and liquid production It can improve the swept area to further displace the residual oil. Previous researches have present that waterflood development of low permeability hydrocarbon reservoir should select smaller well spacing and increased differential pressure between injection wells and production well [20,21,22]. The main objective of this paper is to investigate the effect of the anisotropic permeability on the development of waterflood in different fractures parameters of the diamond-shape inverted nine-spot well pattern. The effects of different fracture lengths in the edge and the corner production wells under different low-permeability anisotropic reservoir were investigated, and a series of unequal fracture length optimization results were obtained. The research results provide reasonable suggestions for the development in low-permeability anisotropic reservoir
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
