Research on the overall optimization method of well pattern in water drive reservoirs

Abstract

Well pattern optimization is an important part of oil field development design. The heterogeneity and anisotropy of the reservoirs should be considered when the wells are distributed. Considering that well pattern is a complex system with the interaction of each well group, this paper has proposed the overall optimization method of well pattern. In this method, the same of the water breakthrough time is the objective function and the location of each well is optimized. In this paper, the calculation method of the water breakthrough time of heterogeneity/ anisotropy non-piston displacement reservoirs has been derived. Compared to the traditional numerical simulation, the new method is more suitable to solve well arrangement problems because of its higher efficiency. The optimal model has been solved by genetic algorithm. A conceptual model has been established to verify the effectiveness of the proposed method. The optimized method can be used to realize the best match between the well pattern and heterogeneity/anisotropy reservoirs.

Well placement optimization for offshore oilfield based on Theil index and differential evolution algorithm

“…Because water flooding performance is mainly influenced by the parameters on mainstream line (Zhou et al 2017;Chen et al 2017b), we use oil saturation in injector-producer line to reflect the displacement process. Because oil saturation is not a constant along the injectorproducer line, the equivalent oil saturation of each injector-producer line X i is calculated by:…”

“…One represents that the displacement is extremely unbalanced. The objective of well placement optimization is to realize maximum equilibrium displacement (Zhou et al 2017). Therefore, the objective function of well placement optimization model is the minimum difference of injectorproducer lines' oil saturations which can be formulated as:…”

“…A proper well placement can yield a balanced displacement and large financial return (Siavashi et al 2016;Awotunde and Naranjo 2014;Ogbeiwi et al 2017). And a balanced displacement process can achieve a good development performance of reservoir (Zhou et al 2017). However, due to the heterogeneity of reservoir and fluid property, the displacement is often unbalanced.…”

“…They adjusted the well placement to make well placement match with the geological vector. Zhou et al (2017) proposed a well placement optimization method to realize maximum equilibrium displacement. In their method, displacement balanced degree was measured by the variance of the water breakthrough time.…”

A prediction formula for ratio of injection–production control area in triangle well pattern

“…2). Because the waterflooding process is mainly affected by the parameters on mainstream line (Zhou et al 2016;Feng et al 2013), the parameters of each part are assumed to be equal to the average parameters of injector-producer line.…”