Offshore in depth

Beginning this month, it is my pleasure to author a monthly offshore column as a contributing editor to World Oil. My focus will be ideas, information and insights on “cutting edge,” worldwide offshore activity. I will also include forward-thinking technology that will give you “food for thought” to make deepwater exploration, exploitation and development more cost-effective.

MODU fleets. As a result of the moratorium put in place by the U.S. Government after the BP/Horizon incident in 2010, a lot of MODUs (Mobile Offshore Drilling Units) have found contracting homes in other parts of the world. This has put a “damper” on rig activity in the Gulf of Mexico for the near term. This will not help develop new reserves, and with the existing deepwater production level declining, it will increase U.S. dependence on foreign resources. Of course, some of this deficit will be offset by the productivity of U.S. onshore developments.

Drilling contracting companies have also shown forward-thinking by ordering new units with greater water depth and drilling depth capabilities, to meet future demand requirements of the operators. New oil and gas reservoirs will be discovered in deeper horizons in many parts of the world. These will be oil and gas reservoirs, along with large gas reserve finds.

The 38 newbuilds, representing a subset of the largest contractors, and which eventually come out of the construction shipyards, will result in additional units joining several companies’ fleets.  A summary of these additions is as follows:
 
Dynamically positioned drillships                         21
Dynamically positioned semisubmersibles           4
Jackups                                                           13
Total                                                                38
 
The existing rig fleet, for a subset consisting of the largest contractors, is distributed among various locations around the world, with 40%-plus located in the North and South American regions.
 
Rig locations by regions, large contractors
Arctic                                                                1
Australia                                                            18
Arabian Gulf                                                       14
Asian Pacific/S.E. Asia                                       34
Middle East & Africa                                           39
North & South America                                       113
North Sea/Norway                                               30

Forward-thinking technology. As operators have moved into deeper water in the Gulf of Mexico, drilling and completion costs have increased significantly, as a result of rig, equipment and personnel costs. Wells are being drilled to deeper depths, adding to the time that a well takes to reach its intended reservoir target(s) and get evaluated.

One technology that can save operators rig time and increase the safety for rig and company personnel would be the incorporation of free-standing drilling riser (FSDR) technology into the subsea drilling riser and control system. Considering the time required to install the drilling riser and associated control system, significant time savings could be realized, if the rig did not have to handle that task, in addition to storage of the riser system. The freestanding riser could be transported, and retrieved, using a separate vessel.

Also, given the BOP testing regulations that have been imposed since the 2010 accident, and the increased cavity requirements, it will be more cumbersome for the rig to handle its movement, required testing/evaluation and storage. In addition, hurricanes require the ceasing of drilling and/or completion operations, temporary abandonment of the well’s borehole, and pulling and storing the riser system before the rig is abandoned for the storm. This could take better than a week, with the same time required to rerun the system after the storm. Implementing the FSDR system would require less than 24 hr, in 6,000–8,000 ft of saltwater (fsw), since the rig would only have to handle less than 1,000 ft of the riser.

When activity resumes in the Gulf, a considerable amount of costs could be saved, making the operator’s development more cost-effective, resulting in improved economics.

Rig schedules and movements back into the Gulf of Mexico are increasing, to work on wells that were temporarily abandoned subsequent to the moratorium imposed by Washington on all companies’ wells being drilled at that time. In addition, new wells that were planned will get back on track, once the appropriate rigs become available to them. Also, there are a number of new deepwater dynamically controlled drillships that will be coming out of the shipyards, to move to other shipyards, to finish their outfitting before starting their initial contract drilling, reservoir evaluation and potential completion operations assignments.