This paper discusses the experiences and good practices established from successfully executing two managed pressure cementing (MPC) jobs within an ultra high-pressure/high-temperature (HP/HT) well in offshore Malaysia.
The risks associated with cementing in sections with narrow margins between pore pressure and fracture gradient can often limit the length of each cased section, hence limiting the final total depth (TD) of the well. A new cementing technique using managed pressure drilling (MPD) equipment and processes allows the wellbore to be displaced with a hydrostatically underbalanced mud after the casing string has landed and then cemented with a hydrostatically underbalanced spacer and cement slurry.
This technique was used to successfully cement an 11 3/4-in. intermediate liner and a 9 7/8-in. production liner, which, in turn, enabled the operator to reach the target depth. The 11 3/4-in. liner was cemented successfully without losses or gains, despite only a 0.2-lbm/gal window (15.6 to 15.8 lbm/gal), with bottomhole static temperature (BHST) of 133°C. This job was executed with a 15.0-lbm/gal mud, a 15.0-lbm/gal spacer, a 15.0-lbm/gal cement slurry, and up to 400 psi surface backpressure (SBP). The 9 7/8-in. liner was also cemented successfully without losses or gains with a 0.9-lbm/gal window (17.4 to 18.3 lbm/gal) with BHST of 163°C. This job was executed with a 17.0-lbm/gal mud, a 17.0-lbm/gal spacer, a 17.0-lbm/gal cement slurry, and up to 600 psi SBP. A cement bond log (CBL) was run for the 9 7/8-in. production liner and the results showed good bonding across the entire openhole section, including the critical target zones. The prejob engineering and execution involved extensive hydraulic modeling, closely coordinated with the MPD service provider, and comprehensive risk analysis and mitigation plans.
Source: SPE/IADC Drilling Conference and Exhibition, 17-19 March 2015, London, England, UK
Authors: Brendon Tan (Halliburton) | James Gillies (Halliburton) | Aizat Noh (Halliburton) | Khairul Anwar Mohamed (PETRONAS) | Farid Wahid (PETRONAS) | Willy Bordessoulles (PETRONAS) | Pankaj Jain (PETRONAS)