Application of rate transient analysis modeling in diagnosis of well abnormal flowing status in Middle East carbonate reservoir

Modern Rate Transient Analysis (RTA) is the hottest technology in recent years in reservoir engineering. Its main working principle is combining production data with bottom-hole pressure data based on the assuming reservoir model and well model. It will evaluate the reserves (Oil Drainage Radius and STOIIP), reservoir properties (permeability), wellbore condition (skin) and forecast production performance for single well based on matching Blasingame and Log-Log type-curve. The RTA was found to be extremely powerful and popular particularly with high resolution to obtain equivalent results with PTA rather than limited shutting well. With benefit of continued monitoring of production and FBHP or FWHP, it is possible to evaluate the wells’ interference and boundary in distance besides conventional reservoir properties. In this paper, taking a carbonate reservoir in the Middle East as an example, this technology was applied to diagnose and analyze the abnormal production of pilot horizontal wells. Based on the analysis results, combining with the understanding of geological study, material balance analysis, numerical simulation and adjacent vertical well’s performance, it is clear that the distribution of mudstone interlayer and reservoir poor connectivity in member-A are the main interior factors of the abnormal production of pilot horizontal wells. According to the research, this paper put forwards optimization of development strategy for subsequent producing subzones, well location and well type of new well in interest area. Key words: Rate transient analysis, type-curve, reservoir properties, carbonate reservoir, Middle East