June 2019 Vol.74 No. 6
Features
Three Parallel Crossings in Corpus Christi
Jeff Griffin | Senior Editor
Hard Rock Directional Drilling has completed three 3,100-foot directionally drilled crossings of the deep-water navigable ship channel in Corpus Christi, Texas. The channel extends from the Gulf of Mexico, through the jetties in Port Aransas and across the Corpus Christi Bay.
The 12 steel pipelines installed in the three crossings were needed to carry crude oil to connect the Pin Oak station to its dock station. The project owner is Pin Oak Terminals, a pipeline and storage terminal operator. The company’s Corpus Christi facilities currently are under expansion.
The primary contractor for the improvements that included the channel crossings project was Strike LLC. Hard Rock contracted for the horizontal directional drilling (HDD) work.
“Although our contract for the bores was with Strike, Hard Rock worked directly with Pin Oak and Oso Development on
the design, drill plan and consultation to obtain all necessary permits before the project was ever awarded,” said Cory Baker, Hard Rock general manager.
Baker explained that the project was made in three bores so the bundles would be manageable for pullback. Each of the three bundles consisted of four pipes: two 16 inches in diameter and one each of 20- and 4-inch diameters. The bores were made side-by-side, one after the other.
“We used our Vermeer D1000x900 drill rig with 1 million pounds of pullback and 96,000 foot-pounds of rotary torque,” said Baker. “Strike had to bring several loads of fill to build the pad up in order for us to be able to set up.
“We made the first bore, moved the rig 15 feet, made the second bore and moved another 15 feet for the final installation. The pipes had to be within a designated right-of-way.”
Drill parameters
Pipes were installed 100 feet below the channel floor. Water was 60-feet deep, making the bores about 180 feet from the elevation of the drilling rig. Soil conditions included sand, shell and clay. An 81⁄4-inch mud motor and 8-inch mill-tooth bits were used to drill the pilot holes.
“Because there were ‘S’ curves in the horizontal plane in the underwater bore paths,” Baker said, “we needed a steering tool that had a high percentage of accuracy without a coil. With the three crossings side by side, accuracy was even more important to ensure we did not fall into one of the already drilled crossings while making these turns. We used a gyro steering system supplied by Brownline.”
The contract allowed 35 days to complete each pilot bore, but Baker’s team was able to average about 28 days per bore and completed work ahead of schedule. Pipes were laid out in a narrow right-of-way and mid-welds were made on all four pipes in each bundle.
“The exit points,” he continued, “were in a very tight and congested area which caused us to have to design the crossings to exit at 15 degrees. That presented a challenge for pulling pipe and getting the proper break over for all the pipes. Strike had to bring in cranes in order to keep all the pipes separated and at the proper breakover to correctly enter the hole.”
To enlarge the bore holes, three passes were made with 30-,
48- and 60-inch reamers, all built in house by Hard Rock.
Cooperation
The three HDD crossings were complete in three months. Reflecting on the job, Baker emphasized that a lot of time was required to plan and develop “the perfect strategy.”
“This was a very challenging project with the horizontal ‘S’ curves and all three crossings being so close together in such a tight space, where there was no room for error. We also staggered the drill paths to insure the safety of already installed lines.
“The key to the successful installation of the crossing bundles was the cooperation among our company, Strike and Pin Oak. I also want to recognize the hard work of Hard Rock personnel Tom Forconi, manager, Maxi Rig Division; Mario Diaz, crew leader for the million-pound drill rig; and Chris Jones, business development manager.”
Based in San Antonio, Hard Rock Directional Drilling provides HDD planning, engineering and construction services.
Strike LLC, of Houston, specializes in pipeline and facility construction, operations and testing, and related services.
Oso Development Partners, of Houston, is an engineering, procurement and construction management company.
The Corpus Christi shipping channel is operated by the Corpus Christi Port Authority. The port is a leading U.S. crude oil export port and the 4th-largest port in the United States in total tonnage. •
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