Study and Application of Diagnosis Curves of Water Channeling Patterns for Horizontal Well in Bottom-water Heavy Oil Reservoir

Abstract

Researches on the water breakthrough patterns and laws of horizontal well are weak. Based on this, a typical model was established by using the geology and reservoir parameters of the heavy oil reservoir with large bottom water in the Bohai Sea. Generally, there are 4 water-out patterns for horizontal well in bottom-water heavy oil reservoir, including punctiform breakthrough waterflooding in a local horizontal section, punctiform breakthrough waterflooding in several local horizontal sections, linear breakthrough waterflooding in the whole horizontal section, and water channeling along high permeability zone. Then, the typical diagnosis curves of these water breakthrough patterns were drawn by studying WOR (water-oil ratio) and its first-order time derivative. However, there are usually value errors in the actual production data, so the interference of noise signals in production data would reduce the accuracy and reliability of water output diagnosis. Using wavelet transform method to denoise dynamic data can simultaneously guarantee both the smoothness and approximation of derivative curves. Finally, the effective measures of different water flooding modes were put forward by the case study of 22 horizontal wells in LD bottom-water reservoir. It has reference significance for efficient development of bottom-water reservoir with horizontal wells in high water cut stage.