Year: 2012.
Status: Complete and approved by customer.
Objectives:
  • To carry out general comprehensive survey of 460 square kilometers as per scope of works;
  • Determine seabed conditions, exact pipelines location/routes, pipeline crossing, sea depths (bathymetry), location details of platforms for future engineering activities.
General seabed survey

General seabed survey includes multibeam echosounder and side scan sonar survey:

  • Identifying all obstructions and other debris;
  • Determination of routes pipelines with coordinates;
  • Determination of pipelines crossings.

Operational pipelines and risers survey

Operational pipelinesa and risers survey includes side scan sonar and multibeam echosounder survey along the pipelines routes:

  • Determination of actual position of pipelines and risers;
  • Route survey with determination of abnormalities along  pipelines routes;
  • Checking and reporting of any crossings.

Operating platform survey

Operating platforms survey include sidescan sonar and multibeam echosounder survey (seabed area around 200 meters) and diving inspection of abnormalities:

  • Determination of platforms location using DGPS survey;
  • Determination of seabed condition around platforms area of 200 meters with abnormalities reporting.

Diving survey
  • Inspection and survey of operating risers;
  • Inspection of operating pipelines including crossing and abnormalities along of pipelines routes 5 meters stripe;
  • Identification and inspection of debris on the seabed that was found before by scanner.

Summary:
  • During the survey was made bathymetry for all area for bathymetry mapping;
  • All facilities on the seabed were reported with coordinates and description;
  • Based on scanner data and diving survey materials detailed reports was issued – maps, 3D models, drawings, operational platforms plans, pipelines profiles, routes, abnormalities reports etc;
  • The 24 operational platforms was inspected during the project;
  • Area around operating platforms was surveyed by scanner and divers;
  • Top side of all operating platforms were measured by DGPS system for exact maping;
  • During the contract, 58 operating pipelines was surveyed by scanners and by divers – routes, crossings, coordinates;
  • Non-commisioned pipelines was also inspected;
  • As result of survey was no found critical damages on operating pipelines;
  • Only abandoned (flexible) pipelines have critical damages;
  • 50 non operational pipelines was surveyed by scanners and divers in order to receive exact coordinates;
  • All pipelines was mapped on general and sectors maps.
  • 156 debris location was found during the survey, all of them were surveyed and reported with description, sizes, coordination.
  • According to received survey data, 3D model of seabed was developed.
  • 3D model can be used for future engineering activities.