Leopold Gretiæ, Crosco Integrated Drilling& Well Services Ltd

Crosco’s jackup drilling rig Labin, a Lev-ingston 111-C, was built at the ViktorLenac shipyard in Rijeka, Croatia in1985.

Labin performed well, drilling wellsuntil 2003 in the Mediterranean(Turkey; Egypt & Tunnisia) and theAdriatic Seas (Croatian & Italian part),mostly consisting of gas exploration andproduction wells and completion andtesting of existing wells.

During that period the rig remainedhighly competitive with other drillingunits of same type due to regular main-tenance and replacement of old equip-ment, upgrading with the improvementsin drilling technology and safety.

After a period of intensive exploitation,regardless of good maintenance andtechnical improvements, the Labinreached the point when a thoroughreconstruction was necessary.

The reconstruction was also requestedby operating companies (especially ENI

Agip, as long term oper-ator). The most impor-tant aim was theimproved possibility towork alongside fixedproduction platforms.Another very importantrequest was the possi-bility to work in waterd epths of 91 m anddeeper.

Due to operating restric-tions to meet thoserequests without thor-ough reconstruction, itwas decided to startthe project.

The reconstructionexceeded our expecta-tions and the Labin hasbecome a modern andhighly competitive unit.Virtually every part ofthe rig was scheduled toundergo some recon-struction, upgrade orenhancement:

Hull and legs:

• Legs extension

• Jack up system modi-fication (additional jack-ing for legs No. 2. & No.3., lower shock absorberreplacement, majoroverhaul of existingjacking system included

new jacking control panel)

• Hull extension (stern and side exten-sion)

• New cantilever extension with newrack & pinion system

• Third pedestal crane installation

• Submersible pumps equipped withrack and pinion system

• Tanks inspection, cleaning &

anticorrosion protection

• ABS class renewal

• Re-certification of all major compo-nents (NDT inspection, service reportsetc.)

Drilling equipment:

• Third mud pump installation (newsuction and pressure mud lines)

• New mud treatment facility

• Two new bulk tanks on bow side

• New zero pollution system

• Additional mud tank (78 m3)

• Third transformer installation

• Cementing unit equipped with dieselengine and placed on main deck (newhigh pressure cement lines)

• Piping replacement (industrial water,mud, black & grey water, air, sewageetc.)

• PVT system

• New BOP stacks 13 5/8” & 21 1/4”

• New accumulator unit

Labin reconstruction results in virtually new rig

Among the enhancements to Crosco’s Labin reconstruction projectwas enlarging and extending the cantilever.

Hull length: 197 ft. Hull length: 210 ft.

Hull width: 184 ft Hull width: 217 ft.

Cantilever skid. cap.: 35 ft. Cantilever skid. cap.: 55 ft.

Operating sea depth: 300 ft. Operating sea depth: 329 ft.

Accommodation cap.: 77 Accommodation cap.: 100

Comparison before and after reconstruction

40 D R I L L I N G C O N T R A C T O R September/October 2004

Accommodation:

• Living quarters capacity increasing to100 persons with high living standard(only single and twin bedrooms)

Safety:

• Additional 2 lifeboats (total capacityin all lifeboats 200 persons)

• New fixed fire fighting system (halonreplaced with ecological FM 200)

• New GMDSS radio system

• Remote monitoring system (tanks,generators, ventilation)

It was concluded that Crosco, with itshuman and technical resources andwith the help of it’s partners, couldorganize and successfully finish thereconstruction. The project began on 15November2003.

After the analysis of technical requests,marine conditions and geographicalposition, Crosco decided to perform thereconstruction at the Nauta Lamjanashipyard on the island of Ugljan (Zadar,Croatia). Crosco hired the shipyardtogether with all its facilities.

The reconstruction was designed andmostly performed by experts fromCrosco, in cooperation with the Facultyof Mechanical Engineering and NavalArchitecture at the University ofZagreb.

The project was scheduled to finish in 3½ months. There were 400 to 500 peopleworking daily in the shipyard. Accom-modation and food was provided nearthe shipyard and medical personnel wasmade available 24 hours a day.

During the reconstruction, the shipyardlooked like a busy beehive.The entire reconstruction was super-vised and verified by ABS surveyors,ModuSpec and Crosco’s QA experts.The entire installation of the new equip-ment was covered with QA proceduresand reports.

However, due to extensive works theproject lasted 2.5 months longer thanexpected.

During this time the workers endured 42days of extremely bad weather (rains,strong wind and even snow) andbecause some of the works had to beperformed at 105 m above the sea level,

the entire situation was made even moredifficult.

Despite all the difficulties, the recon-struction was successfully completed.

The reconstruction has considerablyimproved the unit’s technological capa-bilities. Due to the extent of the upgrad-ing operations Labin has become themost up-to-date unit of its class.

Equipped as it is now, Labin has practi-cally become a newly built unit whichmakes it more competitive on the mar-ket, and its economic and operationallife has been extended by 25 years.

The Labin is presently situated in theAdriatic Sea and is carrying out a con-tract for AGIP. n

September/October 2004 D R I L L I N G C O N T R A C T O R 41