Gazprom's Bluestream Pipeline Project Using the ROV as a Geophysical Platform in 2200m in the Black Sea
Authors: Bucklew Steve 
Published: October 2008

The knowledge contained in this paper will demonstrate the preparation, interfacing, and the data collection development of a multiple sensor array operated simultaneously on an ROV during an ultra deepwater survey to establish a pipeline route between Djubga, Russia and Samsun, Turkey in the Black Sea.

Introduction

There is no known case of an ROV operating a similar array of sensors simultaneously, and to such water depths. All of the sensors had to be isolated from each other and from the ROV in order to protect the sensor signals from electronic "noise'. This noise is typically generated due to the wiring for each sensor being in close proximity to the high voltage wiring typically found in ROV systems. The sensor wiring must be sufficiently shielded in the ROV umbilicals, and all pertinent wiring paths, to include the "Online" survey room and the data collection equipment.

The sensors must also be strategically placed on the ROV to avoid the possibility of acoustic interference between each sensor, and the ROV's electric motor and hydraulic power pack.

Operational procedures during "live boating" operations played an extensive role with the data collection process. It is necessary to establish operational and communication parameters early and adhere to these parameters throughout the course of the survey. Major deviations can have the effect of altering the data product from one survey area to the next.

Communications, (verbal and written), were paramount to the success of the operation. There were approximately ten different countries represented at any one time aboard the vessel. There were steps taken to provide a written format for all personnel to follow, and care was taken to insure that there was an international comprehension with regard to the Operational and Safety commands set forth in the pre-job planning.

Project Overview

Gazprom contracted PeterGaz to conduct detailed engineering and technology development required for a ± 400 km submarine gas pipeline system crossing the Black Sea from Djubga, Russia to Samsun, Turkey. A potentially feasible pipeline route was selected, subject to the detailed evaluation of the identified geohazards and the geophysical and geotechnical features obtained from the reconnaissance survey conducted by NeSA from March to May 1997. The review of the survey results indicated that there were a number of potential geohazards that required further investigation in the form of a detailed survey.

NeSA contracted Canyon Offshore Inc. to conduct these detailed surveys. The overall objectives of the detailed surveys were to:Select routes for three pipelines (two pipelines plus an optional third).Gather the necessary data required for detailed pipeline design.Quantify and delineate potential geohazards.Provide site-specific information required for seismic risk analysis.

The pipeline route corridor surveyed by Canyon varied from approximately 1 km to 4 km in the deepwater section, with water depth range from approximately 20 meters to greater than 2,000 meters. The detailed Geophysical Survey was performed from the Italian survey/DP vessel, Mare Oceano. This work was performed in two steps. During Step 1, the operations primarily included vessel mounted EM12 and Seabat multi-beam echo sounder operations. Towed SSS/SBP operations were also performed using the MAK-1M combined fish. Step 2 primarily consisted of ROV operations, with the option to perform deep tow SSS and SBP survey work as required.