Abstract
This paper illustrates the introduction of the high build-up rate rotary steerable system (HBR-RSS) into the Karachaganak field (operated by Karachaganak Petroleum Operating b.v. – KPO b.v.) in Western Kazakhstan – the first introduction of this technology into Kazakhstan. The first run was in a 1380m-long re-entry sub-horizontal production lateral was drilled by HBR-RSS in 6″ hole, followed afterwards by a logging-while-drilling washdown run.
The well design required a sidetrack off a whipstock out of 7″ Liner at 4800m measured depth with a 6″ bottom-hole-assembly (BHA). The proximity of the re-entry well targets required a directional profile with dogleg severity of 6deg/30m and above. Despite the time and tortuosity gains from using rotary steerable technology in previous wells on this project, it was clear that the build section could only be drilled with mud motors for dogleg assurance reasons. In addition to being able to follow the directional plan, the introduction of HBR-RSS enabled other challenges, such as weight transfer, the effects of higher-than-required tortuosity, and the need for multiple bit runs, to be overcome.
All stages of the job was precisely planned and reviewed between the service provider and customer. The HBR-RSS tool performed as planned and the well was completed in one run, with an effective rate of penetration (ROP) of 8.6 metres per hour.
The introduction of HBR-RSS tools on Karachaganak project has allowed KPO b.v. to rethink the drilling of the reservoir zones in the field development plan – both in the design of new wells and in providing options for existing wells previously considered unfeasible, such as restoring production from existing stock of FSU wells by drilling even higher build-rate sidetracks.
