A New Method for Calculating the Characteristic Shape of the Water Ridge Under Horizontal Production Wells in Marine Sandstone Heavy Oil Reservoirs with Bottom Water

The static and dynamic characteristics of a marine sandstone bottom-water heavy oil reservoir include low structural amplitude, small thickness, strong bottom water energy, high watercut rise speed, significant differences in the watercut change law of wells, etc. Due to the complexities of accurate description of the sweep range and ridge shape of high watercut production wells, the evaluation and prediction of the remaining oil distribution is problematic, as well as the feasibility of the adjustment wells. In this paper, we have studied the dynamic characteristics of the water ridge of horizontal production wells in marine sandstone bottom-water heavy oil reservoirs. First, based on the physical simulation experiments, we discuss the overall morphological characteristics of the water ridge after the bottom water rise and the changes caused by the influence of an interlayer, considering the effect of the horizontal production wells and natural water driving. Second, a new method is proposed for calculating the characteristic shape of the water ridge in the heavy oil reservoir in the presence of the bottom water. The new method can be used for quick and accurate calculations of a 3D water ridge shape under horizontal production wells in reservoirs, with or without interlayers. It can also facilitate the quantitative evaluation of the water ridge sweep range of production wells in the high watercut periods. The new method can be applied to predict the remaining oil distribution range and reserves and provide important technical background for development adjustment measures and potential tapping for this type of heavy oil reservoir.