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8537255 
Meetings & Symposia 
Совершенствование технологии стимуляции скважин на основемоделирования СКО и комплексирования лабораторных ипромысловых данных 
Khuzin, R; Shevko, N; Melnikov, S 
2020 
Society of Petroleum Engineers 
SPE Russian Petroleum Technology Conference 2019, RPTC 2019 
English; Russian 
Formation damage of near wellbore zone, which occurs during different well operations (drilling, workover), has dramatic influence on well productivity. To improve well performance the removal of damage or creation of new channels, which bypass damage zone, is necessary. For solving this issue, the acid matrix stimulation is widely used in carbonate reservoirs. In order to design and optimize stimulation treatments the simulation modeling is widely used nowadays. One of the critical issues, which influence the stimulation efficiency, is estimation of near wellbore damage zone parameters and taking them into account during stimulation design preparation. Usually this zone is described as the uniform zone with permeability, which is different from reservoir permeability. However, in reality its structure is complex and contains at least two damage subzones with significantly different parameters. Moreover, in case of perforation the created channels can have a positive as well as a negative effect on near well bore zone. The influence of these subzones is also not taken into account in used in practice models for calculation of skin factor due to presence of perforation. These factors influence the efficiency of acidizing stimulation and should be taken into account in modeling process. In this paper, we present details of the approach, which takes into account the complexity of near well bore damage zone and its modification during acid stimulation. For this purpose the combined skin factor is introduced that takes into account the present damage subzones with different permeabilities, perforation channels, wormholes, relative permeabilities and viscosities of pumped fluids and their changes during acidizing process. The combined skin factor approach was implemented into created simulator for matrix acid stimulation, which is used successfully in designing and optimization of stimulation operations on the Company's carbonate fields. The paper, in the example of one of the green oil fields, describes the evolution of well completion and stimulation technologies based on acid matrix stimulation modeling and integration of laboratory and field data. The proposed recommendations allowed to reach the values of skin factor up to −5 and involve into production up to 95% of reservoir thickness. Copyright 2019, Society of Petroleum Engineers