Drilling advances

	Vol. 224 No. 12
ROBERT E. SNYDER, EXECUTIVE ENGINEERING EDITOR

Rig Directory time again. This issue contains World Oil’s Marine Drilling Rigs 2003/2004, a 64-page listing of 625 mobile offshore drilling units separated into four categories: jackups, semisubmersibles, drillships/ barges, and submersibles. It’s been a quiet year for offshore rigs; there are 10 fewer listings this year, and the October Offshore Rig Locator (ORL) shows 18 rigs of the above categories under construction, vs. 23 a year ago. But overall utilization of all mobile offshore rigs improved slightly, to 70.5%, vs. 68.6% last October. The Gulf of Mexico was up about 9%; the North Sea was down about 5%, with a few less rigs in each area. 

In a couple of last-minute changes that didn’t make the listings, Diamond Offshore says it intends to retire its Ocean Century and Ocean Prospector semis that have been cold-stacked for five years. And Pride International has renamed the two semis it co-owns and manages – the Amethyst IV and V, listed under Petrodrill – to the Pride Rio de Janeiro and the Pride Portland, respectively. Both rigs were undergoing final upgrading in November. 

And the year is not ending strongly for floaters. The ORL said in October that floating rig demand (semis and DP drillships) was 131 – lower than the 139 mark of six months ago, and lower than the 138 mark of one year ago. Floating rig utilization in the US Gulf was barely over 50%, and Europe/ Mediterranean floater utilization was only 64%. These two regions account for close to half of the worldwide floater market. 

More standards and recommendations. ABS updated its Guide for Certification of Drilling Systems, which provides risk-based classification. Technical advances in the offshore industry and regulatory developments have spurred the update. First published in 1985, and last updated in 1990, the Guide references current standards and API recommendations. It provides industry with an option for a “safety case” or risk-based analysis approach to certification, rather than applying the more traditional prescriptive rules reflected in the 1990 version. With continued changes in regulatory regimes, the certification of rigs, including the drilling systems, is expected to further evolve. 

ABS’s market share for rig classification is around 76% of the world fleet, representing 512 drilling units classed with ABS. The Society’s certification continues to provide the offshore industry with an option for certification on behalf of regulatory authorities, such as the UK Health & Safety Executive (HSE) and the Norwegian Petroleum Directorate (NPD). Four newbuild GlobalSantaFe rigs contributed to an immediate need to update the Guide, and provided a model for industry-wide application. 

The participating units, all built in Singapore yards, include two semis, Development Driller I and II, and two jackups, Constellation I and II. “Industry will reap the benefit of the lessons learned on this project with more cost-efficient rig certification,” says ABS. Copies of the new Guide will be available at year’s end on the ABS website: www.eagle.org.

Lost Time Incident (LTI) rate improves. As reported in PTTC’s 3rd Quarter Network News, in an excerpt from the July/ August Drilling Contractor, according to IADC’s 2002 Summary of Occupational Incidents, the drilling industry’s worldwide LTI rate dropped to an all-time low of 0.65, 12% better than the previous low of 0.74 in 1999. Fatalities dropped to 15, five less than in 2001, but still higher than the nine in 1999. 

Conclusions are based on data from 100 contractors, representing about 70% of the worldwide rig fleet, and a total 281 million man-hours worked. For the US, both land and offshore LTI rates improved, vs. 2001 data, by 22% and 25%, respectively. 2002 LTI rates for land workers are higher than for offshore workers, e.g., 1.73 for land, vs. 0.5 for offshore. Employees with service time of 1 year to 5 years accounted for most LTIs and Recordable injuries – those with less than one year accounted for 40%. 

New technologies. Schlumberger Oilfield Services says its Seismic-While-Drilling Measurement reduces uncertainty ahead of the bit. The new logging-while-drilling system acquires and transmits seismic data in real time without interfering with normal drilling operations. 

The patented seismic VISION system delivers traditional borehole-seismic measurements, including checkshot and interval velocity data in real time. Seismic waveforms are available in memory. In-time access to such calibration data is critical where large uncertainties in the time-depth relationship exist, or in wells where it is essential to set casing in a particular interval identified by the surface seismic data. With the checkshot continuously correcting the seismic map, both the driller (in depth), as well as the geologists and geophysicists (in time), can see in real time where they are on the surface seismic map. 

The new system has been successfully tested in a variety of offshore locations. A client in the Caspian Sea used the service to reduce seismic uncertainty to 30 ft, from 2,500 ft, to confirm and hit the target location. Another client in the Gulf of Mexico used the service to drill within 60 ft of the base of salt, and then used the wave forms to look ahead and identify features below the salt. For information: www.slb.com/oilfield/seismicvision. 

Baker Oil Tools introduced industry’s first fit-for-purpose Cement-Through completion system. The new, patented Mono-Trip CemenThru completion system brings added safety and artificial lift capability to cemented monobore wells. First runs of the new system were scheduled in late 2003 in the Gulf of Thailand. 

The system was developed to add artificial lift capability and improved safety to cemented monobore wells. Components specifically designed for cement-through applications include a patented side pocket gas lift mandrel, a tubing-retrievable, surface-controlled subsurface valve, and a hydrostatic circulating valve. The system also includes a hydraulically set liner top packer, a dual wiper plug and a latch collar. For more details on the system, check: news.releases@bakeroiltools.com.

Small article correction. For those of you who haven’t noticed, probably 99.76%, in the October 2003 article, “Aphron-based drilling fluid: Novel technology for drilling depleted formations,” the photos of Adrian Chesters and Sven Maikranz were inadvertently switched, relative to the biographies. Now when you meet Adrian or Sven, you’ll know who they really are. Sorry, guys.