Stretching hundreds or thousands of feet into the dark waters below a mobile offshore drilling unit (MODU) is the conduit through which all operations and fluids fl ow. The primary purpose of the vessel’s offshore riser system is to enable the safe transportation of fluids and gases from beneath the seafloor and the surface, and vice versa. From the running, operation and retrieval of drillpipe to well control operations and more, any and all processes that require a surface connection to the well are made possible through riser systems.
The connection is established through a series of 27-m (90-ft)-long riser joints connected together. The integrity of these individual riser joints is paramount, presently requiring inspections every fi ve years to identify any flaws in need of repair. Logistically complex, the inspection process requires the physical transportation of the joints and other components by water to a landbased facility for disassembly, inspection and repair. This approach requires extensive boat trips and trucking of the riser, according to Stress Engineering Services (SES), a provider of consulting engineering services.
SES sought a way to reduce the complexity and the time and costs associated with the MODU inspection process. By partnering with LaserStream, a specialist in the use of laser-based measurement for the inspection of oil and gas equipment and pipe/tubing, a new approach was developed.

The companies combined the power of conditionbased maintenance and monitoring with laser measurement to determine the condition of drilling riser joints, predict when vital components will require service and determine remaining component life. The program uses synchronized drilling and metocean data, along with measured loads on the riser and wellhead system, data analytics and more.
In addition, the process includes data collected through the use of a laser profilometry bore erosion measurement and inspection system (BEMIS). Featuring a scanner head that rotates 250 rpm, the BEMIS can collect more than 3,000 points of measurement in each rotation. These measurements are collected on the inside diameter (ID) of the main bore and auxiliary line between wells to characterize the state of the drilling riser joints. The datapoints are analyzed using the LaserViewer software to map and determine material loss, characterize features to determine what caused the anomaly and perform detailed dimensional analysis of the entire tube, according to SES.
The BEMIS is deployed through the ID of the riser via a tethered crawler while the riser is on deck and eight joints can be inspected in one day. Field results are available at the site, and a final report identifying damage is available within a week.
Recommended Reading
Ring May Drill—or Sell—Barnett, Devonian Assets in Eastern Permian
2025-03-07 - Ring Energy could look to drill—or sell—Barnett and Devonian horizontal locations on the eastern side of the Permian’s Central Basin Platform. Major E&Ps are testing and tinkering on Barnett well designs nearby.
Hibernia IV Joins Dawson Dean Wildcatting Alongside EOG, SM, Birch
2025-01-30 - Hibernia IV is among a handful of wildcatters—including EOG Resources, SM Energy and Birch Resources—exploring the Dean sandstone near the Dawson-Martin county line, state records show.
APA's Apache Reports Another Oil Discovery on Alaska's North Slope
2025-03-17 - APA Corp. and its partners plan flow tests after the success of the Sockeye-2 exploratory well.
E&P Highlights: Feb. 24, 2025
2025-02-24 - Here’s a roundup of the latest E&P headlines, from a sale of assets in the Gulf of Mexico to new production in the Bohai Sea.
Sitio Fights for its Place Atop the M&R Sector
2025-04-02 - The minerals and royalties space is primed for massive growth and consolidation with Sitio aiming for the front of the pack.
Comments
Add new comment
This conversation is moderated according to Hart Energy community rules. Please read the rules before joining the discussion. If you’re experiencing any technical problems, please contact our customer care team.