New Casing Exit Technology Cutting Costs in High Profile Offshore Environment

摘要

Applying whipstocks and casing mills to kick-off out ofrnexisting wellbore has become commonplace. However,rnthis operation is becoming more critical becausernextended ratholes are often required to accommodaternlong rotary steerable assemblies out of casing beforernnew formation drilling can commence. This extra trip,rndepending on window depth, can take up to two daysrnworth of rig time and significantly increase well costs.rnIdeally, the window milling and thole drilling should bernperformed in one run to improve operational efficiencyrnand cut drilling costs.rnTo address this developing niche, a new-style formationrnmill (NSFM) has been developed by Baker Oil Toolsrn(BOT) and Hughes Christensen (HCC). The NSFMrnutilizes technology from HCC’s industry-leading GenesisrnPDC line. The tool uses a special PDC compoundrndesigned to effectively cut both metal and formation. ThernNSFM also has specially engineered spiral set cutterrnalignment that reduces vibration while large waterrncourses keep the PDC cutters cool for increasedrnendurance. The NSFM also has the capability ofrnadapting to any BOT whipstock system or can be run asrnstandalone technology, providing a one call solutionrnresource.rnSince its introduction, the mill/bit has been used inrnvarious regions. Performance has been closelyrnmonitored in applications ranging from 4-1/2” tubingrn(3.800” OD) TT exits to 13-5/8” 88.2# Q125 casing (12-rn1/4” OD) in deepwater salt to 7” 32# P-110 casing (5-rn7/8” OD)in 30,000 psi dolomite with chert nodules.rnThe versatile tool has saved numerous trips on simplernhard rock sidetracks in the Rocky’s as well as in deepwaterrnGOM plays where rotary steerable drilling systemsrnwere being utilized to save trips and push the reachablernenvelope. The authors will document this cost cuttingrnperformance improvement with several in-depth casernstudies. The authors will also discuss how the NSFMrnwill play an important role in helping operators reachrnpreviously un-economical reserves.