Transocean Shelf Explorer Starts Drilling on Veninsky Block

On June 30, the Transocean Shelf Explorer jackup started drilling on the Veninsky Block at the Sakhalin-3 project, in which a 74.9% stake belongs to Rosneft and the remaining 25.1% are held by Sinopec.

The drilling was ordered by the Project operator, Veninneft LLC, which had scheduled the drilling of two exploration wells during the 2009 field season.

The first Veninsky Block well will be drilled at a distance of roughly 10 kilometers from the shore, with the actual drilling site lying 25 meters beneath the sea. The second well will be located on the North-Veninsky structure, almost 9 kilometers offshore and 21 meters deep. The drilling operations will last till the middle of October.

The drilling will be controlled by Veninneft, while supply, transportation and communications will be provided by the Russian companies working on the Sakhalin island.

Launched in 1982, the Transocean Shelf Explorer has since been repeatedly upgraded. The last large-scale modernization of the rig (completed in April this year) was specifically commissioned by Veninneft in order to adapt the rig to the future operations on the Sakhalin continental shelf.

REA-Sakhalin company will be responsible for the environmental monitoring of the drilling area, while a special Rubin ship will provide a 24-hour stand-by duty to prevent and clean-up spills of oil and oil products.

Sakhalin-3 Project

Rosneft and Sinopec are involved in the exploration of the Veninsky, a 5,300 sq.-km. block located on the Sakhalin shelf of the Sea of Okhotsk. Sea depth in this area ranges from 25 to 150 meters. In April 2003, Rosneft obtained a prospecting and exploration license to this block.

The existing project plan envisages onshore drilling of 5,000-8,500 meter-deep exploration wells using cutting-edge drilling techniques similar to those employed at Sakhalin-1. Assuming successful exploration results, all wells at the Veninsky block will be drilled using horizontal and directional drilling from both onshore and offshore platforms.

In 2006, the first exploration well was drilled, tested and liquidated at the South-Aiyashskaya structure of the Veninsky block. As a result, prospective oil and gas-bearing strata were revealed and tests confirmed the presence of hydrocarbons. Drilling was carried with the help of the Kantan-3 floating semisubmersible drilling rig owned by the Shanghai Offshore Drilling Company.

In 2007, 680 sq. km. of 3D seismic were shot at the Veninsky block. In addition, project participants started preparations for the drilling of an exploration well at the North-Veninskaya structure, which is planned to be performed in 2008. In particular, Rosneft and Sinopec prepared design documentation for the well and obtained required approvals, purchased necessary equipment, signed core and auxiliary services agreements, and carried out engineering and geological studies. Furthermore, the exploration license to the Veninsky block was extended through 2010.