The typical horizontal well in Permian Basin tight oil resource plays now consumes more than 13 million pounds of frac sand on average. As perwell average proppant consumption has increased, a steady stream of technological and operational advancements has been introduced to optimize transport, storage and delivery capabilities to get more sand to each well site in less time in order to keep pace with the frac pumps.
The supply chain has been revolutionized by in-basin mines and last-mile logistical solutions such as mobile containers. These changes put the source of supply in close proximity to the well, remove bottlenecks to moving sand from the mine to the blender hopper, lower the delivered cost of frac sand, provide a storage buffer at the pad, reduce noise, and minimize dust and truck traffic.
The next step in further improving efficiencies and reducing costs eliminates a common but often overlooked step in the mining process: drying. Before transferring to the blender and pumping down hole, mined sand is washed, dried, sieved, stored and transported to the wellsite. Drying involves a combination of decanting (allowing water from the washing process to naturally drain and the sand to air dry in a pile), followed by handling operations to feed the sand into a kiln.
A new approach uses patent-pending equipment to screen, transport, deliver and meter wet sand from local in-basin mines to the frac blender, bypassing the drying process altogether. Wet sand in this application is defined as sand with a moisture content between 1% and 10% by weight. Frac sand historically has been dried prior to transporting to reduce its weight and improve ease of handling. A container carrying 25,000 pounds of sand that is 3% wet by weight translates to 24,250 pounds of net sand load and 750 pounds of water.
Drying operations introduce operational bottlenecks and adds incremental cost to each ton delivered. For frac sand mine operators, the capital and operating expenses for kilns can be considerable, and drying plants and storage are often limiting factors in mine output. An added benefit of eliminating drying is the positive environmental impact of eliminating billions of Btus of energy needed to fire kilns and the associated emission reductions. For oil and gas operators, drying provides no direct value to well construction, and once delivered to location, the sand is reintroduced to water in the frac fluid anyway.
This article from the August 2020 issue of The American Oil and Gas Reporter highlights the latest innovation from PropX – an innovative and patent pending last mile frac sand logistics system designed to deliver wet or dry sand from the sand source to the frac blender. More than 1 billion pounds of wet sand have been delivered with this technology. The benefits of delivering wet sand are many: lower cost, substantially less energy required and lower emissions due to eliminating the drying process, eliminating silica dust, removing substantial capital investment needed at a mine site, and reducing makeup water consumption at wellsite among other benefits.