CASE STUDIES
CACHE CREEK GAS LINE
Side-By-Side HDD Installation
PROJECT SUMMARY
Environmental standards have changed dramatically over the years. In 1960, a natural gas line was permitted to be installed along the bed of Cache Creek near the town of Capay (an hour west of Sacramento). In 1991, a larger parallel line was placed at the same location. When the owner applied to replace both lines in 2014, the new 914 mm and 1067 mm (36 in and 42 in) lines were required to be installed at a safe depth safely below the water crossing. The HDD Company was subcontracted to complete the drilling.
The plan called for both lines to be installed parallel to one another at a depth of 24.4 m (80 ft) below the creek bed.
KEY CHALLENGES
This project involved tight timelines. The initial plan called for one HDD rig working in 24-hour shifts. After assessing the sites entry and exit points, the HDD company provided an alternative suggestion: to bring two HDD rigs onsite (located 21.3 m/70 ft apart) and complete both crossings simultaneously. It was felt the entry point was more than sufficient for both rigs and all support equipment, while the exit point allowed ample room for materials, the welding crew and pipe stringers.
Both pilot holes were completed in little over two weeks, then reamed to the required size. The larger pipe emerged 0.37 m (1.2 ft) from the designated exit point, while the smaller pipe emerged 13.4 m (44 ft) from the expected exit.
Clear communication, a collaborative planning process and solid execution ensured this important pipeline was back online in little over four months from the start of construction.
