• Pipeline Matrix

The Pipeline Matrix

Pipeline operations encompass a large proportion of offshore field development projects. Activities include pre-lay bathymetric surveys of the site, laying of pipelines, umbilicals and jumpers, out-of-straightness surveys and all tasks required to commission a field and obtain first production.

Inside the Pipeline Matrix, subsea positioning requirements for each operation will be influenced by factors such as accuracy and area of coverage required. Sonardyne's solutions are low risk, multi-functional and cost-effective ensuring your projects are completed on time and on budget.

Route and Site Surveys

Route surveys involve surveying the whole area of the field using sensors mounted on towfish, ROVs and AUVs. The surveys are conducted long before the field is developed and as such, no existing field positioning systems will be in place making the project ideally suited to high accuracy independent positioning systems such as Sonardyne's 6G® USBL techniques.

Site surveys tend to take place immediately prior to pipelay and are conducted by an ROV. Online results are used to immediately identify possible pipeline hazards which calls for both accuracy and precision for real time multibeam or sidescan imaging. 6G® techniques and Sonardyne's new imaging sonar technology provide the optimum solution.

 

Pipelay Operations

A pipelay project involves many tasks including: Initiation, Touch Down Monitoring, Crossings, Mattress Lay, Inline Structures, Laydown, Cut To Length and As-laid surveys. For all of these tasks, the accuracy and independent operation of Sonardyne's

6G® USBL systems provide cost effective solutions whether it is deployed directly from the lay vessel or from a support vessel. In areas requiring high accuracy or relative positioning such as pipeline crossings and narrow lay corridors, 6G® sparse LBL aided INS increases system performance without the cost of large seabed equipment deployments.

 

Post-Lay Operations

Rock dumping requires both accurate and precise positioning. Due to the high acoustic noise created by dumping, pure acoustic tracking can be problematic. Sonardyne's 6G® inertial systems mounted directly on the chute not only smooth poor acoustic positions but also provide reliable positions during complete acoustic blackouts.

Out Of Straightness surveys require the most accurate and precise navigation of any of the pipeline operations. For OOS tasks at specific areas such as at a buckle arrester, a Sonardyne 6G® seabed LBL system will provide the highest accuracy.

If the area is to be monitored over a long period of time, an LBL setup using Sonardyne's 6G® autonomous monitoring transponders allow deformation to be monitored cost effectively and correlated with events such as pressuring up and changes in product temperature. Inspection surveys often require more precision than accuracy as the pipeline start and end is generally well known. To provide precise positioning for sensors such as multibeam echo sounders Sonardyne's 6G® USBL aided Subsea INS technique offers the solution.