Optimized drilling saves time in Persian Gulf

• Published in: The Oil & gas journal Vol. 118; no. 9; p. 45
• Main Authors: Khosravanian, Rasool, Aadnøy, Bernt Sigve
• Format: Magazine Article
• Language: English
• Published: Nashville Endeavor Business Media 07-09-2020
• Subjects: Boreholes; Cementing; Drilling; Drilling rigs; Monte Carlo simulation; Offshore drilling; Oil fields; PERT; Program evaluation; Project evaluation; Statistical methods
• ISSN: 0030-1388; 1944-9151

A comprehensive study of new phases for Statoil South Pars phase development optimized drilling times. Using South Pars drilling history in Phases 6, 7, and 8 as a guide, different approaches were evaluated to improve and optimize drilling times using Monte Carlo simulations (MCS) and program evaluation review techniques (PERT). Conventional drilling, batch drilling, and casing-while-drilling were compared. Batch drilling saved 5 days/well over conventional drilling, and casing-while-drilling saved an additional 4 days/well. Further improvement to drilling times used casing-while-drilling in which two main operations are combined and cementing costs are saved by reducing annulus volume. There is no need for separate casing or liner runs as all borehole sections are drilled and cased, ready for cement. This scenario results in safer drilling operations by requiring fewer people on the rig and less pipe handling than routine drilling.