In a world of labor shortages, increasing labor costs and decreasing productivity, we’re all looking for solutions that lower cost while increasing project certainty. Modularization can help! Where traditional construction has all work taking place on the worksite, with buildings stick-built in place, piping and equipment installed and set piece by piece, and electrical run cable by cable, modularization takes a portion of this work and completes it offsite in controlled environments with experienced crews. Once assembled, each module is sent to the site to be installed, fitting together much like life-size LEGO® pieces. The JV Driver Group has been a part of numerous billion-dollar facilities that were constructed in this very way, saving time and money while increasing quality and project certainty. In these two case studies, we would like to present the benefits of offsite modularization versus erection in an on-site industrial environment.
Case study No. 1: Mini-modules for a petrochemical facility
As part of a larger project, the JV Driver Group was tasked with utilizing a front-end engineering design (FEED) study to create an estimate for the installation of a new 8-inch fuel gas line and a new 8-inch boiler water line within an existing facility. This portion of the project was in a brownfield area (100-percent spark containment and full permitting) of the refinery and 30 feet or so above grade on an existing pipe rack, which ran parallel to a refinery main road that was also the primary evacuation route.
From the tangled web of steel, cable tray and pipe, it was evident the rack had been retrofitted numerous times over the years. However, the resident engineer was able to find a route to weave in roughly 2,600 linear feet of new pipe.
The intent was to hand-rig single random ~20-foot lengths of pipe onto one end of the rack, then use tirfors and rollers to drag the pipe into place. From there, the pipe was to be welded, radiographed, hydrostatically tested, heat traced and insulated. For us to complete the work in this fashion, much of the existing rack would need scaffold and hoarding.
This method of installation has been used for many years and could be considered the traditional way to execute this scope.
During bid meetings, the client stressed it was not looking for a generic off-the-shelf plan; the client wanted a special “something” to fit its specific needs. We needed to demonstrate that we really did “Think Different, Build Better” on all phases of the project, and not just during the project execution phase after the contract was awarded.
On top of this, the team also needed to solve the execution-related problems identified by both the client and JV Driver during the bid phase:
• The street the work occurred on was the main access to the plant and the designated emergency access route. Therefore, road closures/ disruptions resulting from the work needed to be minimal or, better yet, nonexistent.
• The traditional approach would require a large multidiscipline workforce in a low-productivity and hazardous area. This would mean more craft hours spent working at elevation in a brownfield area.
• Pipe would be fished into place in 20-foot lengths, which required 150 field welds, plus the expansion loops on the boiler water line, which would need another 14 field welds. A 100-percent spark containment was required for all welds. In addition, owner-issued hot work permits were needed.
• All the radiographic examination would need to be completed at elevation in a brownfield area.
• All 2,600 linear feet of heat tracing and insulation would need to be completed at elevation in a brownfield area.
• Extensive scaffold requirements.
• High labor cost.
• Execution in an operating plant at elevation in a brownfield facility comes with greater safety risks than in a greenfield area.
How could we reduce the amount of brownfield work? Could we modularize any portion of this? Why couldn’t we change the routing proposed in the FEED study?
What we ended up proposing was to modularize the two new lines and bolt the assembly onto the side of the existing pipe rack.
By choosing this approach, we ensured large portions of the work could be completed at grade in our fabrication shop/module yard, as opposed to working from a scaffold deck in a brownfield area. Safety, productivity and quality went up, and labor costs went down. Through this modularization, the project and client received the following benefits:
• 70 percent of the piping works completed prior to arrival on-site.
• 85 percent of the heat tracing and insulation completed prior to arrival on-site.
• 70 percent of the radiographic examination completed prior to arrival on-site.
• Field weld count was ~50, which is less than a third of the field welds in the traditional approach.
• Scaffolding was substantially reduced. Decks were needed at the expansion joints and a couple other locations; but there was no need to deck out the existing rack.
• Potential reduction of ~7,500 field labor hours spread across multiple disciplines.
Case study No. 2: Modularization of a SAGD facility
This project was a 35,000-bpd steam-assisted gravity drainage (SAGD) facility consisting of 118 modules including pipe racks, equipment modules and stair towers. Here are some high-level quantities of work that we removed from the field and completed in our module yard:
• 181,119 linear feet of piping
• 3,031 tons of steel
• 160 pieces of equipment
• 26,400 linear feet of heat trace
• 176,072 linear feet of insulation
All this was done while reaping the benefits outlined in case study No. 1.
Summary
Modules can vary in size and weight from a 2-ton pipe rack to a 4,000-ton LNG compressor module or anywhere in between. There are also compounding reductions in indirect costs including equipment operators, scaffolding, and labor and staffing costs in shop environments. In most situations, the savings you can achieve by moving items out of the field and into the module shop will exceed the additional costs for transportation and shop overheads.
If you compare actual productivity from JV Driver’s module facility with field construction and Westney Consulting Group’s overview of performance metrics for the Gulf Coast, the advantages across all metrics become clear. Modularization outperforms in all areas. Further information on this comparison is available in Table 1 below. JV Driver’s productivity has been set as the baseline for the analysis in this table.
Westney shares a high-level view of key project overview metrics on an annual basis to improve industry knowledge and project planning. These baseline metrics can serve as the basis for your own project overview analysis. The metrics included in this chart are Westney’s view for 2016.
Table 2 identifies the available modularization split (labor hours completed in a module yard versus the balance of work on the module to be completed in the field: hydrostatic testing, tie-in welds, insulating tie-in welds, cable pulls, etc.) for four key disciplines: piping, structural, insulation and electrical.
The true success of a modularization plan is ensuring you move as many hours offsite as possible by thinking outside the box. If you can move hydrostatic testing, painting, scaffolding, equipment setting, electrical trays and fixtures, instrumentation and insulation to the module yard, the more likely it is the module plan will make sense. Remember “shipping air” is the largest obstacle to overcome in a modularization plan.
Understanding your specific project is critical for making an informed decision on whether to modularize. Innovation is the cornerstone for all module plans, and JV Driver can assist with all your modularization planning and execution needs. Specific execution strategies, early engagement between the engineer and constructor, and timelines are key to the success of any modularized project.
For more information, visit www. jvdriverusa.com or call (866) 391-5816.
