The practice of hydraulic fracturing—a technique designed to accelerate the recovery of gas and oil from low-permeability rock—has evolved significantly since its first applications by Standard Oil and Halliburton, beginning in 1947. From the first commercial treatments in 1949, the industry has advanced to employing more than 60,000 hydraulic horsepower and over 3,000 truckloads of proppant per fleet, per month. This journey—from humble beginnings to the sophisticated, high-volume frac operations of today—highlights the importance of modern wellsite operations, proppant supply and high-efficiency wellsite proppant delivery systems.
FROM GRAINS TO GAINS
Since the first hydraulic fracturing trials, numerous materials have been used as proppants: from naturally occurring river sand and industrial minerals, to synthetic materials, such as glass beads, floating proppant, plastics, aluminum shot and high-strength and lightweight ceramics, as well as resin-coated proppants. The manufacturing of some of these specialized synthetic proppants, such as resin-coated sands and ceramics, that were prominent in the early days of hydraulic fracturing, introduced additional layers of complexity to the manufacturing process and supply chain.
These proppants, developed to enhance the performance of hydraulic fracturing operations, undergo intricate manufacturing processes, involving either washing, drying and coating with resin or the creation of strong, high-conductivity ceramic particles from select materials—primarily alumina and various clays. These added steps not only increased the cost but also introduced more potential points of failure in the supply chain, from production delays to transportation, storage and wellhead delivery challenges.
The evolution of frac proppant from heavily synthetic, complex products to more simple silica sand has significantly transformed wellsite delivery from the initial operations. In 1949, Standard Oil employed an eye-watering volume of 150 pounds of sand for that first commercial frac treatment. This sand was manually added to a modified 55-gallon drum for pumping. Over time, as daily proppant demand grew, the wellsite delivery method evolved from using simple dump trucks and 3,000-lb super sacks to pneumatic trailers, along with increasing on-site sand storage capacity. Innovations like mountain movers—and later, silos and containerized systems, which drew inspiration from the shipping container concept of modular, predictable delivery—further improved storage and reduced supply disruptions at the wellsite, Fig. 1.
Fig. 1. Proppant per well in U.S. shale basins since 2010. Data provided by Lium Research.
Wellsite equipment used for precise, metered delivery and storage has evolved equally as fast, driven by market forces of ever-increasing daily proppant demand. Proppant demand in North American shale plays has increased by 400%, with a 10% CAGR since 2010 alone, going from around 35 million tons in 2010 to an estimated 120 million tons in 2024. This specialized equipment, designed to handle these modern high volumes, has been through countless iterations of innovation, Fig. 2.
Fig. 2 First commercial frac, 1949, in Alma Field, northeast of Velma, Okla. Deese Sand was used, with Prefrac equal to 24 bopd and Postfrac equal to 52 bopd. Fluid used was Napalm, from Imperial Paper. Proppant used was 150 lbs of 20/40 Ottawa sand.
A SHIFT IN THE SAILS
Building on the transformative narrative of frac sand delivery in hydraulic fracturing, we now delve into the era of changing sources of proppant and the cascading effect on innovations within the industry. Defined as beginning around 2017, this era heralded a paradigm shift, phasing out the dependency on railroads for sand transport and ushering in a new wave of logistical innovations.
As the American shale revolution began to evolve from 2000 to its current form, the historical supply chain for frac sand, during the period from 2010 to 2016, revolved around sand sourced primarily from Wisconsin and Minnesota. This glacially formed sandstone, known for its superior purity, sphericity and strength, was believed to yield better and more economical well results, and it set the standard within the industry. The operational reliance on Northern White sand created a supply chain characterized by multiple storage and handling points, with a multi-week timeframe from origin to delivery, thousands of miles away. This intricate system was fraught with the risk of disruption and high costs.
During the fast-paced years of 2017-2021, beginning in the Permian basin, a massive transition towards local or "brown" sand began to take shape. The discovery and utilization of local brown sand fundamentally altered the frac sand supply chain, by mitigating many of the logistical challenges and high costs associated with railroad transport and transloading. This pivotal change not only simplified logistics but also significantly reduced transportation and operational costs.
By leveraging sand sources closer to shale plays, particularly in the Permian basin, the industry achieved a remarkable reduction in lead times from mine to wellsite, transitioning from weeks to days or hours. This near-basin sourcing effectively eliminated the railroad's role in sand delivery, cutting down on multiple handling and cost points and reducing the risk of supply disruptions. Almost overnight, massive capital flowed into the sector, and a local race for resources and deposits emerged. Costs began to fall, and the complexity of the supply chain was reduced; however, the knock-on effects created massive operational bottlenecks, which were evident at the wellsite.
Operators recognized a direct correlation between volume of proppant and production. When this realization was paired with massive frac crew efficiency gains, sand volume requirements per hour, per day and per month were sent to all-time highs for frac fleets, and they continue to set records each year. Next-generation software and tracking platforms borrowed from the shipping container industry helped to organize the delivery chaos and wellsite concepts, in order to smooth wellsite inventory fluctuations and minimize disruptions. These modular container systems and silo systems with much larger inventories became the norm within the industry. These systems also provided operators with the ability to continue to push efficiency with their fracturing crews, while minimizing the risk of downtime waiting on proppants due to operational supply chain constraints.
TRADING PLACES
There are trade-offs with proppant selection and onsite storage options. Local sand is cheaper than Northern White, due primarily to eliminating rail transportation as part of the supply chain. However, this local “brown” sand is lower-quality and less conductive, so more of it is used to make up for that deficiency. Sand from local mines is typically mined, washed, dried, sized and stored. Trucking is performed with pneumatics and increasingly with boxed containers and belly dump “grain style” trailers, with hauling distances of typically 50 to 150 mi. Local fixed mines typically are characterized by a longer last mile, but they totally eliminate a large cost and risk input: rail car loading, transporting and transloading. This local mining can eliminate 25% to 50% of the total delivered sand cost.
Onsite, there are trade-offs as well, depending on frac sand daily throughput, equipment style, and operator preference. The older style mountain movers with pneumatic trailers have largely been phased out, due to lower throughput capability and higher silica dust exposure. They’ve been replaced by onsite silos and containers/boxes. These newer delivery systems have dramatically reduced noise, dust and truck standby time for offloading, due to their design efficiency. The proppant is well-protected from the elements, accurately inventoried and dispersed quietly, accurately and safely into a frac blender when needed. It also allows for more wellsite storage and more consistent delivery of sand, which can be 100 or more loads per day for a typical modern frac operation in 2024.
ALL WET
As the modern frac sand supply chain and delivery mechanisms began to take shape, an even more disruptive shift arose. The fundamental question of why sand is dried, only to then mix it with water in order to pump it downhole, had the industry scratching its head. Again, innovation occurred. The development of wet sand wellsite delivery systems in 2020 marked a pivotal shift in the industry's approach to proppant supply chains.
This novel approach was driven by the recognition of the considerable costs and environmental impacts associated with the drying process—traditionally a critical step for preparing sand for ease of transportation, storage and use. By eliminating the need for drying, the industry could leverage wet sand (defined as 5%-to–10% water by weight) directly from local mines, significantly simplifying the supply chain and reducing both costs and emissions related to the drying process. This significant change in the proppant type, sheer volume and origin of the product surfaced operational challenges at the wellsite that had not been considered in the past, Fig. 3.
Fig. 3 Proppant type as a percentage of total U.S. shale basins’ market demand since 2014. Data provided by Lium Research.
This time, the delivery and storage mechanisms at the wellsite brought on another wave of change. Once service and equipment providers, along with completions teams, realized that wet sand could be delivered, stored and metered reliably, the introduction of hyperlocal (also called mini-mobile or proximity) wet sand plants began to emerge. These plants brought proppant production even closer to the wellhead. Where surface sand resources are available, these smaller, more agile mining plants could be strategically located near wellsites, drastically reducing transportation distances, costs and emissions profiles. This development not only bolstered supply chain resilience but also improved uptime of the just-in-time delivery models that were unique to the frac sand application to operational support. This development ensured a consistent and reliable sand supply for hydraulic fracturing operations.
Increasingly since 2020, more mines are providing damp sand: local sand that has been mined, washed and not dried, decanted slowly from large piles at the mine site. This damp sand is now available in most every unconventional basin except for the Northeastern U.S., at the time of writing.
More than 20% of the Permian basin’s sand capacity is from wet sand. Twenty-five of these hyperlocal plants have been built or have been announced. This will cause dramatic dislocations in the frac proppants markets in the coming years. In addition, damp sand can be purchased from local “fixed” mining sites, which produce sand, wash it and then choose how much to send through the driers, versus how much to sell as wet sand.
A mine generally needs to produce more wet sand than it can dry, to ensure that the driers, which are expensive to start and stop, do not run out of sand to dry. Increasingly, mobile or “proximity” mines are popping up, particularly in the Permian basin, which has a plethora of surface sand dunes suitable for frac sand. Damp sand is oftentimes cheaper, with some of the cost savings due to eliminating the drying process.
For example, less fuel is needed for kilns, there is less cost for silo storage and fewer mining staff are needed per ton of sand sold. Couple this with the cost savings from reduced permitting, expanded storage cost and the—generally speaking—closer location to where the drilling and completion activity is taking place, and the savings and simplicity are too significant to ignore. The closer location, alone, can result in an up-to-90% reduction in trucking intensity, and the stage is set for another wave of disruptive innovation in the proppants industry. This will result in significant cost savings to one of the most expensive frac and well cost inputs, making up around 30% of total completion costs.
THE JOURNEY CONTINUES
The journey from the manual addition of sand in the early days of hydraulic fracturing to today's sophisticated logistics models highlights the industry's relentless pursuit of innovation. The transition towards local brown sand, the advent of wet sand delivery systems and the development of hyperlocal sand plants all represent key milestones in this journey. As the industry continues to evolve, the potential for further innovation in frac sand logistics remains vast, with even greater efficiency gains, environmental sustainability and cost-effectiveness possible in the future.
BACK TO THE FUTURE
Damp sand is opening the door for new wellsite delivery methods. For example, pads with extremely large daily sand throughput requirements of more than 14 million pounds are trying different techniques, including a move back to where it all started, with sand put into a pile from dump trucks or some variation thereof. This dramatically increases the sand storage volume at a pad site while also substantially increasing the size of the pad.
This method, of course, also comes with trade-offs: more sand on site ensures longer supply security. On the other hand, the sand is stored in the open and is subject to the elements of rain, wind and ice, and the large volumes stored require a much larger footprint. In addition, the ability to mix wet and dry sand together is eliminated in a pile, due to employee exposure risk to silica dust. Product can be lost, due to wind or erosion, and tracking inventory can be challenging. The industry will iterate on these ideas and in a few years’ time—if history tells us anything— proppant delivery won’t look like it did a few years before.
AND BEYOND
As the container model is maturing and many silo systems now have iterations with quick and reliable load and offload times, a new question requires pondering, regarding the now potentially outdated last mile cost and efficiency model. Over the last six years, loads are sourced and paid to truck drivers in a $/ton model. Primarily, this has been due to a focus on maximizing each load’s volume.
However, like everything, this point-to-point model has trade-offs. Unlike all other trucking and last-mile models from other industries, this model disincentivizes strategic warehousing and does not make efficiency and inventory management onsite the top priority. Take airlines, for instance, with their hub-and-spoke approach. This system is efficient for managing flows of goods, information or transport from a central point to multiple locations. Another approach is decentralized distribution, used by e-commerce companies like Amazon, primarily to increase customer satisfaction and delivery speed.
The unprecedented advance in wellsite delivery and storage mechanisms, combined with the scale and volume of modern proppant use, will foster new models that may be more effective at solving our modern challenges. For example, a multi-modal delivery strategy utilizing containers and bottom drop trucks, combined with decentralized warehousing methods, could work more efficiently at scale. Different methods of transportation could be used to take advantage of the cost and efficiency benefits of each mode over different segments of the route. Add in a strategically placed mobile warehouse that can naturally flex inventories up and down—whether a pile of damp sand or inventory of proppant containers—and the variable real-time sand demand can be met in a more efficient, organized and cost-effective manner. The scale of modern demand will change everything—again!
This modernization of the wholistic delivery method undoubtably will drive innovation yet again at the wellsite, in throughput, as well as equipment, technique and logistics software. This will lead to figuring out how to right-size the pad area, combine efforts with water transfer and create even more optionality for the provider base to deliver a high-quality service to the customer base.
Frac sand and proppant supply have evolved massively over the past decade and are still changing rapidly, with new ideas and new techniques. Lower-quality proppant saves money but necessitates higher pumped volumes per well. This change in cadence spurred the evolution of onsite storage and delivery equipment. On-site equipment provided a catalyst to change trucking and logistics models. Now models provide opportunities for proppant sourcing closer to the wellsite. The innovation cycle continues in a circular manner, and there is no end in sight. Innovation is a powerful force in the proppant and proppant delivery market that has created tremendous value for shale companies in the U.S. As shale gas is developed around the world, these learnings will travel there, as well to unlock tremendous value to global supply chains.
About the Authors
BRIAN DORFMAN
PropX
BRIAN DORFMAN is V.P. of Operations and co-founder of PropX, a company based in Denver and dedicated to providing innovative equipment and services for last-mile frac sand and logistics. He has 12 years of experience working in a variety of oilfield service roles focused on drilling and completions.
KEVIN FISHER
PropX
KEVIN FISHER is president and co-founder of PropX. He has served in a variety of roles in oilfield servicing firms, primarily centered around hydraulic fracturing and associated technologies.
CARL T. MONTGOMERY
NSI
CARL T. MONTGOMERY is a senior engineer with NSI Technologies. With 52 years of experience in well stimulation design and execution, he has lived and worked in 54 countries during his career. Mr. Montgomery is a member of the “Legends of Hydraulic Fracturing” community and is currently serving on the FORGE geothermal advisory committee.
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