THE CAUSES OF OCCURRENCE AND REMEDIES FOR CROSS-FLOWS BEHIND CASING AND ANNULAR PRESSURE WHILST DRILLING FOR OIL AND GAS ЗАКОЛОННЫХ ПЕРЕТОКОВ И МЕЖКОЛОННЫХ ДАВЛЕНИЙ ПРИ СТРОИТЕЛЬСТВЕ НЕФТЯНЫХ И ГАЗОВЫХ СКВАЖИН
Samsonenko, Alexander V. – Cand.Tech.Sci. , deputy general director LLC Vyazhushchee-Service, speccem@rambler.ru speccem@rambler.ru
Самсоненко Наталья Владимировна – к.т.н., генеральный директор ООО «Вяжущее — Сервис», канд.тех.наук. speccem@rambler.ru
УДК 622.24
Key words: cement slurry, cross-flows, annular pressure, casing integrity.
The paper concentrates on how to improve the quality of well casing. It shows that while portland cement slurry or lightweight and heavy slurries set and harden in the borehole annulus, the filter cake on the borehole walls and the film on the casing string dry and small gaps occur between cement and casing, resulting in channels for cross-flows behind casing. An expanding powder slurry has been designed, which includes a thermally stable plasticizing and expanding agent that is added to portland cements supplied by different cement factories. Given the high temperatures and formation (pore) pressure during the WOC period, the setting time is substantially reduced and cement stone expansion decreases.
THE CAUSES OF OCCURRENCE AND REMEDIES FOR CROSS-FLOWS BEHIND CASING AND ANNULAR PRESSURE WHILST DRILLING FOR OIL AND GAS
Samsonenko, Alexander V. – Cand.Tech.Sci., deputy general director, LLC Vyazhushchee-Service, speccem@rambler.ru
Samsonenko, Natalia V. – Cand.Tech.Sci., general director, LLC Vyazhushchee-Service, speccem@rambler.ru
Key words: cement slurry, cross-flows, annular pressure, casing integrity.
The paper concentrates on how to improve the quality of well casing. It shows that while portland cement slurry or lightweight and heavy slurries set and harden in the borehole annulus, the filter cake on the borehole walls and the film on the casing string dry and small gaps occur between cement and casing, resulting in channels for cross-flows behind casing. An expanding powder slurry has been designed, which includes a thermally stable plasticizing and expanding agent that is added to portland cements supplied by different cement factories. Given the high temperatures and formation (pore) pressure during the WOC period, the setting time is substantially reduced and cement stone expansion decreases.
