Pipeline ROV inspection in Mexico

ServiceROV Pipeline inspection and Cathodic protection survey
LocationGulf of Mexico, offshore Ciudad Del Carmen, Campeche.
Water depth15 – 1300 m
Project duration10 months (2018)
IndustryOil & Gas
scope of work
ACSM was contracted by a Client in Mexico to carry out ROV inspection over 261 existing pipelines, between 15 and 130 meters water depth, including crossings and intercommunications.

The scope of the work included:

  • ROV general visual inspection (GVI) of the pipelines with the aim to identify their locations and physical conditions.
  • Cathodic protection survey by measuring the CP potential and verifying whether or not the anodes are still functional.
  • Evaluate the conditions of the concrete mattress, their position on the ground, interconnections and crossings with other existing lines to identify any potential hazard that might affect the stability and structural conditions.
  • Identify any natural and artificial hazard on the seabed, as well as objects that have fallen to the bottom of the sea and/or are abandoned.
  • Detection of gas or oil emanations (leaks or dirt tracks), line displacements with respect to its laying alignment, undercuts, anchor dragging and location of objects fallen to the seabed (metal debris in direct contact with the line).
  • Calculate the burial depths of submarine lines and interconnections.
  • Detect freespans and scours.
  • Detect consumed and inactive disconnected anodes.

VESSEL

Go Electra
As vessel platform, ACSM hired the DP2 “GO ELECTRA” a versatile, agile and multipurpose vessel.
The vessel was able to accommodate 66 people, including Crew, ROV personnel, survey team and Client’s reps.

ROV

ACSM Saab-Seaeye Panther XT ROV
Due to the shallow water work area, ACSM chosen the electric Saab Seaeye Panther because of its reduced dimensions that allowed a considerable savings in terms of timing, due to the easy deploying the 700 kg Panther system rather than the much heavier hydraulic alternatives.
However, the potent thruster power of the Panther was able to handle a large array of equipment needed for full survey work and provided the steadiness and agility needed to continue working even in strong currents.

In addition, the electric vehicle was acoustically quieter than hydraulic vehicles that means the Panther was able to provide accurate multi-beam sonar data.

SURVEY EQUIPMENT

  • Norbit Dual Head MBES
  • ROVINS INS
  • Tritech Super SeaKing sonar
  • Blueview 2D imaging sonar
  • Teledyne Navigator DVL
  • TSS 440 pipetraker
  • CTD profiler
  • Laser Line
  • Cathodic Protection sensor
METHODOLOGY
The inspection was carried out with ACSM Saab-Seaeye Panther XT ROV in free-flying mode over the pipelines.

Where the pipelines were exposed, dual MBES data acquisition and visual inspection have been carried out to identify any possible faults/hazards. The cathodic protection system measured the CP potential over the pipeline with the aim to estimate the life time of the anodes.

Where the pipelines were buried, the burial depth have been measured by the TSS440 pipetracker.

The recorded data have been acquired and processed by using EIVA Navimodel that allowed to work simultaneously with different kind of data (MBES, pipetracker, pipe model, CP values, videos and blue-view from ROV) and deliver user-friendly formats to the Client.

RESULTS
Survey Scope achieved:

ACSM inspected 261 pipelines totaling of 2,340 km in four fields in the Gulf of Mexico (GOM), at depths ranging from 15 to 1300 meters, in a less than 10-month project duration.

Survey Daily production:
An average of 8 kms of daily production was achieved which represent a great result as the majority of the pipelines were.
Milestones achieved:
Operations were carried out smoothly and safely with no significant equipment downtime and zero LTI.
Client satisfaction:
Client was satisfied about the offshore works and extremely pleased to have received the final report with reasonable time from the end of the operations.

Turning complex subsea challenges into safe and efficient operations