Platform Spacer raises Molikpaq for Sakhalin II development

Russia Far East yard adapts to project schedules

Victor Schmidt
International Editor

PART I: This is Part I of a multi-part series on development operations off Eastern Russia's Sakhalin Island. The series will continue in upcoming issues with reports on geosciences, drilling and other facets of production.

The Sakhalin II consortium is completing a major element of the Phase 1 development of the Piltun-Astokhkoye license area - the refurbishment of the Molikpaq platform. The consortium consists of four members: Marathon Sakhalin Ltd., Mitsui Sakhalin Development Co. Ltd., Diamond GasSakhalin B.V. (Mitsubishi) and Shell Sakhalin Holdings B.V. The original consortium also included McDermott, which sold its share to the consortium.

Marathon Upstream Services is handling early exploration and development of the project. Shell will handle the downstream LNG plant. Japan's interests through Mitsui and Mitsubishi are fabrication contracting, steel and consumables, as well as hydrocarbons for domestic consumption in Japan. Information coming from the various Sakhalin Island production sharing agreements has been limited.

Adapting the Molikpaq

A key element in the development program was the drilling island - the Molikpaq. Molikpaq's hull was originally designed by Sandwell/IHI and built in a Japanese shipyard for Gulf Canada for use in the Canadian arctic. It was later sold to the Sakhalin Energy consortium and has been undergoing refitting for use offshore Sakhalin Island.

The Molikpaq was originally designed for 20-meter water depths; too shallow for the 30-meter water depth at Piltun-Astokhkoye, the first of Sakhalin II's oil fields. A steel Spacer was designed that would mate with the base of the Molikpaq, adding the extra height. In general, the 15,000-tonne Spacer appears as a four-sided football field (only larger) with a running track around the top. Maximum length of the Spacer is 110 meters.

The Spacer was built in the Amur Shipbuilding Plant (ASP), a former submarine yard at Komsomolsk-n'Amure, Khabarovsk province (Russia Far East) on the Amur River. The facility was originally constructed by Stalin in 1932 for the production of commercial shipping and submarines, and has built over 300 hulls.

The yard has narrow bays, only 19 meters wide, which forced the Spacer to be built in four separate sections. After construction, the Spacer sections were floated down the Amur and towed to Bolshoi Kamen near Vladivostok, Russia for joining.

Hull assembly

After positioning the individual hulls in the shipyard basin, a caisson is installed on the underside, covering the hull joints to just above the waterline. The caisson interior is then pumped free of water. Water pressure forces the caisson's rubber seals together against the Spacer hull ensuring a watertight workspace. The Spacer sections are then welded together in this dry environment.

Upon completion of fabrication in mid-March 1998, the Spacer was transported south across the Japan Sea to Okpo, Koje Island, South Korea. There Daewoo Heavy Industries is refitting the Molikpaq for operation offshore Sakhalin and adding a 2,500-tonne production module to convert the former drilling unit into a drilling and production platform.

Daewoo will undertake mating the two structures in Korea. First, the Spacer will be lowered below sea level by flooding the buoyancy chambers. Next, the Molikpaq will be floated into position over the Spacer and aligned. Once the two units are properly positioned, the Spacer will be deballasted, raising both itself and the 32,000-tonne Molikpaq out of the water. Once a good fit is ensured and the two pieces properly shimmed, they will be permanently welded together using exterior closure plates.

Installation on-site

Sail-out of the combined modules will take place late summer. The new extended Molikpaq will be towed from Korea to the eastern coast of Sakhalin Island for installation. It will be positioned over the Astokhskoye feature of the Piltun-Astokhskoye oil field after site preparation, which includes leveling and emplacement of a gravel pad.

The Molikpaq will be positioned, and then the buoyancy chambers will be flooded, settling the structure on the pad. Approximately 300,000 tons of densified dredged materials and gravel will completely fill the 30-meter deep interior space to provide resistance mass against ice and wave forces. The exterior will be ringed with rock for scour protection. Even with all this material in-place, the Molikpaq remains a moveable system that can be used elsewhere in the future.

Yard challenge

"Almost all the possible variables were changed for ASP," said Ernst H. Gwydir, Site Manager, Spacer Fabrication, Sakhalin II Project. "This was their first fixed price contract for a foreign oil company. It included engineering, which ASP subcontracted to Rubin Design Bureau, St. Petersburg, Russia. In past projects ASP was driven by Rubin and now ASP was in control. Another new variable was the very short time frame to complete the work and the fact that there would be an owner's site team (foreigners in the formerly closed city) to contend with. In addition, they had to deal with Japanese steel and welding consumables, which, while being very good, were completely unknown to the yard. Although the welders came to love the flux core wire, there were initial 'teething' problems, which included modifying all the welding machines to accept the Japanese consumable cassettes. They (ASP) did a damn good job. I'd be happy to work with these guys anytime anyplace."

Bonuses were attached to all parts of the job, and were distributed to all the employees. Prior to this job, some workers had not been paid for 6-8 months. "They came to work every day, something you wouldn't see anywhere else in the world," Gwydir quipped. "They worked just about every hour there was to work." With the work at its peak from March through June 1997, some workers were earning as much as 18 million rubles (about $3,000 per month), excellent money for Russia.

Now, the work is over and there is a delay in the work schedule. The next platform job may not begin until the year 2000 or later. Exxon had planned to use the yard for Sakhalin I related fabrication, which would have begun immediately after the completion of the Spacer project, but experienced delays. There is a danger that the skilled workers will move away.

Christening the Spacer

On another facet of yard personnel involvement, hulls in Russia are always named. Eighteen female students from the local pedagogical institute, who work as part-time translators for the Sakhalin Energy site team, threw their names into a hat for a drawing. Four names were drawn: Yana, Julia, Olga, & Tatyana. Yana won the honor of christening the first hull.

It is a Russian tradition that the lady christening the hull be dressed as a bride. Interestingly, Yana was recently married and still had her gown. By tradition, three champagne bottles were used to christen each hull at the bow, midsection, and aft.

What's next

The Spacer Project is more than a month ahead of schedule. Submergence trials were eliminated saving approximately one week. Hard work gained the additional time. The yard will finish with maximum bonus.

Sail-away of the Spacer to Korea occurred in March. Sail-away of the extended Molikpaq to Sakhalin Island is scheduled for August 1998. First oil from the Piltun-Astokhskoye Field is planned for 1999.

Acknowledgements

The author wishes to thank David Golder, Executive Vice President- Upstream, Sakhalin Energy Investment and Ernst H. Gwydir, Site Manager, Spacer Fabrication, Sakhalin II Project, for providing the information in this article. Mr. Golder is on loan to Sakhalin Energy from Marathon Oil Co. Mr. Gwydir, an independent contractor, has 21 years experience in all phases of international oilfield construction. He has worked on one other Russian construction project for Polar Lights in Timan Pechora.

East Russia's potential and future

Sakhalin Island is 15 km from the Russian mainland and the southern tip is only 43 km from Japan's northern island, Hokaiddo. Hydrocarbons produced from Sakhalin Island will have positive benefits in both directions.

"There is quite a bit of latent industrial capability and a lot of good strong technical capabilities in the population, both on the mainland and to a lesser degree, but definitely present, on the island. There is just no infrastructure. There's no business knowledge. There's no capital to develop (industry)," notes David Golder, Executive Vice President - Upstream, Sakhalin Energy Investment Co. Ltd.

What is needed are strong joint venture companies or Russian companies that can develop the needed capabilities. The consortium is seeking to build long-term relationships that will undergird the 25 or more years that production will flow from these fields. "We want to maximize the ability to place the work in Russia wherever we sensibly can," Golder stated, "We have had a very good experience in the Spacer (project) with the quality and work ethic of the people, the willingness of the yard people."

Speaking of the consortium, Golder said, "We feel we can be the first to show a dependable supply of hydrocarbons out of the Russian Federation into the big markets of China, Korea, and Japan. The consortium hopes to spur future development, entrepreneurial activity, trust, and goodwill. It also intends to prove the production sharing agreement concept to Russian authorities."

As many as three additional platforms will be needed to develop Sakhalin II. These systems will be different than the Molikpaq conversion, more efficient as well. Elements to be developed include standard basic designs, equipment specifications, norms and standards for offshore projects in the region.

Sakhalin Energy is working with the other consortia to create these elements. Establishment of these will facilitate maintenance, sharing of spares and cost control as well as smoothing the approval process.