American Oil and Gas Reporter - August 2017 - 46

SpecialReport: Hydraulic Fracturing Technology
At the same time, the "frac intensity," or amount of proppant
pumped per foot of horizontal lateral, continues to grow.
Recall that in 2014 frac sand logistics already were challenged
with sand mine capacity shortages, traffic issues on railways,
insufficient in-basin storage and transload capacities, and "last
mile" logistics from the transload facility to the wellhead
proving woefully challenged to keep pace with demand. It is
not hard to imagine that during the historic downturn in oil
prices and activity levels, little additional capital was employed
to improve the infrastructure necessary to efficiently deliver
frac sand. Now that activity levels are rebounding, the entire
frac sand supply chain from mine to well may be tested severely.
Sand mines are expanding, with typical effective capacity at
around 80 percent of nameplate capacity and new mines are
being permitted. This is especially true in Texas, where local
"brown sand" closer to the point of use (as opposed to "white
sand" sourced primarily from the Midwest) has come into favor
because of its ability to debottleneck from rail capacity constraints
and to reduce delivered costs while meeting operators' technical
requirements.
Delivering The Goods

Since sand mine supply must be available to match demand,
and assuming railway interruptions can be kept to a minimum,
the final pieces (and most controllable from a pumping company
or operating company perspective) in the proppant supply chain
are transload storage facilities and last mile logistics.
Last mile refers to the transport of sand from in-basin or
near-basin storage facilities to the wellhead. Oil field research
firm Infill Thinking estimates that the last mile process comprises
as much as one-third of the total delivered cost of frac sand.
The last mile market is extremely fragmented in terms of the
number of players involved, as well as the types of technology
employed. For example, in the Permian Basin alone, Infill
Thinking tracks more than 40 hauling companies operating significant fleets and many more "mom and pops" running only a
handful of trucks.
Typically, frac sand and ceramic proppants are brought from
the source (mines or plants) to a storage location in or near the
basin where they will be pumped. The most effective method
TABLE 1
Proppant Demand and Supply
Using Conventional Pneumatic Systems
Proppant demand per well delivery
Average per rail car
Rail cars per well
Average per truckload
Truckloads per well
Daily frac demand
Truckloads per day
Pneumatic offload time per truck
Total truck offload time
Truck offload time per 24 hours
Pneumatic truck demand

12 million pounds
220,000 pounds
55
46,000 pounds
260
6 million pounds
130
45 minutes
5,850 minutes
1,440
4.06 days

46 THE AMERICAN OIL & GAS REPORTER

of transportation from sources outside the basin deals with
"unit trains" consisting of 110-120 railcars, each containing
200,000-220,000 pounds of proppant. Unit trains have been reported as long or longer than 150 cars, which would stretch
more than 1.25 miles long. There are wells being stimulated
today which require a full unit train of sand and an average horizontal well now requires half of a unit train load.
Before it can be delivered to the well site, all that proppant
has to be unloaded from railcars to trucks or into storage silos
at in-basin transload facilities. Coras Oilfield Research reports
that there are now about 200 transload facilities in the United
States with a cumulative nameplate capacity of 126 million
metric tons with these facilities expected to grow their total
capacity by 15 percent in 2018.
While this capacity is more than the expected usage in 2018,
it is concentrated among the large pressure pumping companies
and is also concentrated in only 50-60 unit train-capable
facilities. Also, consider that perhaps 30 percent of the capacity
of the unit train-capable facilities is contracted by oil and gas
companies, putting smaller pressure pumpers and other operators
at risk of supply disruptions, and leading to a potential source
of bottlenecks in the proppant supply chain.
Numbers For Thought

It is no secret that frac intensity and proppant volumes
continue to climb, even as drilling efficiency has gone off the
charts in terms of number of wells drilled per rig each year.
Consider that proppant intensity is now more than 1,400 pounds
per foot of lateral, with several in the U.S. basins at or above
2,000 pounds/foot and some wells reported at as much as 5,000
pounds/foot. A total of 12 million pounds of sand a well is a
reasonable assumption for the typical unconventional completion
in a two-mile lateral (Table 1). Assuming a typical rail car from
a mine holds 220,000 pounds of proppant, the average U.S.
horizontal well now requires 55 rail cars full of sand (half of a
unit train for every well completed).
Each truck will carry an average of 46,000 pounds of
proppant, so transloading those 55 rail cars requires 260
truckloads that must be delivered to the wellhead. Given the
standard completion practice of "zippering" multiple wells on a
pad, some pads are efficient enough to allow a single frac crew
to pump 5 million-6 million pounds or more of sand a day, exceeding 130 truckloads of sand that must be delivered each day
to a single pad.
When using pneumatic trailers for delivery, each truckload
requires 40-70 minutes to unload, depending on the pressure at
which the air pumps are set for blow off (higher pressure means
faster unloading, but it also increases proppant damage and
stirs more dust). For 130 truckloads of sand at 45 minutes of
unloading time a truckload, it takes 5,850 minutes (97.5 truck
hours or four full truck days) to unload, so at least four truck
unloading slots will be completely utilized all day, every day.
This requires a significant amount of space and perfect execution by the sand coordinators, frac operations crew and
drivers to keep that sand flowing to the blender. The only thing
that a frac crew leaves behind at the end of a project is the sand
American Oil and Gas Reporter - August 2017

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