INVESTIGATION OF PACK-OFF FORMATION DURING DRILLING OF COMPLEX FORMATIONS
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This study investigates the hydrodynamic and mechanical mechanisms of pack-off formation during well drilling in complex geological conditions. The processes of effective bottom-hole cleaning, transportation of rock cuttings through the annular space to the surface, and the factors contributing to the accumulation of cuttings on the drill-string surface are analyzed. The flow velocity, pressure and direction of the drilling fluid, the location and geometry of the flushing channels, bit design, drill-pipe rotation, and the relative motion of cuttings are considered as the principal factors governing pack-off formation. It was found that under conditions of insufficient upward velocity of the drilling fluid, favorable hydrodynamic conditions arise for cuttings to be retained in the annular space and concentrated toward the outer surface of the drill pipe. The continuation of such conditions intensifies local cuttings accumulation and increases the likelihood of pack-off formation. A deeper study of the pack-off formation mechanism provides an important scientific basis for developing technical and technological solutions aimed at preventing this complication during drilling. In the study, the law of energy expenditure in dynamic systems is considered as a theoretical approach that makes it possible to explain the trajectory of cuttings movement and the mechanism of their approach to the drill-pipe surface. The results indicate the need for coordinated optimization of parameters such as the arrangement of flushing channels, nozzle geometry, flow exit angle, hydraulic pressure, and drilling-fluid flow rate to achieve effective bottom-hole cleaning and prevent pack-off formation. In particular, directing the hydraulic-jet flow toward the bottom-hole surface was assessed as one of the important conditions for improving the separation of cuttings from the bottom zone and their upward transport through the annular space.
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References
[1] Рязанов, Я. А. (2005). Энциклопедия по буровым растворам. Летопись.
[2] Булатов, А. И., Проселков, Ю. М., & Шаманов, С. А. (2003). Техника и технология бурения нефтяных и газовых скважин: Учебник для вузов. Недра-Бизнесцентр.
[3] Басарыгин, Ю. М., Булатов, А. И., & Проселков, Ю. М. (2000). Осложнения и аварии при бурении нефтяных и газовых скважин. Недра-Бизнесцентр.
[4] Негматов, Ж. Н., Негматова, К. С., Эгамбердиев, Б. Ш., & Рахимов, Х. Ю. (2017). Актуальность и востребованность технологического решения по предупреждению сужения ствола и обвала стенок скважин в глинистых отложениях в процессе бурения нефтегазовых скважин. Композиционные материалы, (2), 76–77.
[5] Аксенова, Н. А., Бахарев, М. С., Гаврилов, Е. И., Грачев, С. И., & Зозуля, Г. П. (2006). Справочник бурового мастера (Т. 1). Инфра-Инженерия.
[6] Ҳайдаров, И. Қ., & Самадов, Ш. Ш. (2019). Аварии при бурении нефтьяных и газовых скважин виды аварий, их причины и меры предупреждения. В Инновацион иқтисодиётдга ўтиш шароитида уй хўжаликларида тадбиркорлик фаолигини оширишнинг иқтисодий ва молявий механизмини такомиллаштириш: Республика амалий анжумани материаллари.
[7] Rahimov, A. A., Murtozayev, A. M., & Haydarov, I. Q. (2022). Бурение наклонно-направленных и горизонтальных скважин. Қарши муҳандислик-иқтисодиёт институти.
[8] Калинин, А. Г., Власюк, В. И., Ошкордин, О. В., & Скрябин, Р. М. (2004). Технология бурения разведочных скважин (с. 146–170).
[9] Калинин, А. Г., Ганджумян, Р. А., & Мессер, А. Г. (2005). Справочник инженера-технолога по бурению глубоких скважин (с. 314–377). Недра-Бизнесцентр.
[10] Умедов, Ш. Х. (2010). Разработка составов промывочных жидкостей для бурения скважин на сильноминерализованной пластовой воде [Автореферат диссертации на соискание ученой степени кандидата технических наук]. Ташкент.