Mature Field And Well Revitalization: Selection Of Well Candidates For Matrix Acidizing

Abstract

The author was motivated to conduct this study due to a notable drop in the production of mature fields in Indonesia. This decline in production can be attributed to several factors, including reservoir heterogeneity, resulting in an uneven distribution of fluids and pressure within the reservoir. Well-stimulation techniques such as matrix acidizing can be employed to increase well production. With matrix acidizing, acid is injected into the formation surrounding the wellbore to dissolve minerals and improve permeability, thereby increasing the flow of fluids from the well. Before implementing this method, the well screening process must be conducted to optimize workflow efficiency and ensure that the wells are suitable for matrix acidizing. This paper presents a comprehensive workflow to identify the most qualified candidates for matrix acidizing. The heterogeneity index (HI) concept is used to classify the well's condition and other parameters, such as the well's estimated ultimate recovery (EUR). After obtaining a short list of wells, nodal analysis, well design for matrix acidizing, and potential gain calculation from stimulation results are performed. The study evaluated 24 wells and identified three suitable candidates for matrix acidizing, all showing significant production increases according to the production data. This study proves that using the HI concept for well selection and matrix acidizing stimulation can effectively raise well productivity in Indonesia's mature oil fields.