Sakhalin Single Point Tanker Loading Unit (TLU)

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Single point mooring structure

Sakhalin Energy Investment Company Ltd. (SEIC) is the operator of the Sakhalin II Project located in eastern Russia. This project involves the development of offshore oil and gas fields located on the Sakhalin Island Shelf in the Sea of Okhotsk.

The Project includes a Tanker Loading Unit (TLU) which is installed 4 km offshore in Aniva Bay at the south of Sakhalin Island, in a water depth of approximately 30 m. Crude oil and condensate is delivered to the TLU via a 30-inch subsea pipeline. Electrical power is provided by a subsea cable.

The TLU consists of a Single Point Mooring (SPM) structure allowing visiting tankers to weathervane according to the combined influence of wind, current, waves and ice.

The TLU is equipped with a mooring hawser and boom supported loading hose to accommodate crude oil tankers up to 150 000 DWT in size, throughout the year.

Working directly for SEIC, Ausenco initially carried out the Front End Engineering and Design of a gravity based TLU substructure.

Later working for the EPC contractor, Nippon Steel Corporation, we were responsible for the detailed design of the pile based TLU substructure, with SBM of Holland responsible for the design of the rotating head structure.

The TLU substructure is designed to resist significant ice, wave, wind, seismic and vessel collision loads. Wave loadings were computed using the in-house program WAVE3D.

Advanced finite element non-linear models were used to analyse the TLU for the various load cases using the commercial programs SAP2000 and ABAQUS. Detailed design of the plated elements to the substructure was carried out to Canadian offshore codes and DNV using the in-house program SPPANEL.

The set down of the structure was completed in October 2005.

Project details

Arctic engineering
Aniva Bay, Russia
Business line
Process Infrastructure
Sakhalin Energy Investment Company Ltd. and Nippon Steel Corporation
Solution phase
Evaluate, Innovate, Create