When you see “ADD,” I doubt what first comes to mind is “augmented drainage development.” It never did before with me, either, but it does now. I say that, because two papers on the subject of augmented drainage development (ADD), recently presented at the Unconventional Resources Technology Conference (URTeC),1,2 really caught my attention.
Basics of ADD. As one paper states, ADD utilizes open-hole laterals that offset standard plug-and-perf (PnP) completions, with all wells/laterals drilled in the same batch. The ADD laterals, drilled in the Bakken shale in this case, are passively stimulated by the hydraulic fractures from the offset PnP wells. Also noted is that “ADD well performance is a function of distance from the offset fractured (PnP) wells and treatment design.” What had not been addressed in work prior to these most recent studies and publications were issues, such as “acceleration versus standard development using tighter well spacing?”1
Overcoming skepticism and cost. One reason that the papers caught my attention more than usual was because it reminded me that when the principal authors first presented the notion and recommended ADD wells to their company’s asset management, it was met with skepticism, to say the least. Who in their right mind would drill a horizontal, open-hole lateral in the Bakken without the need for multi-zone fracturing and expect economic production?
Another reason, and reminder to me, was how these unique ADD wells, completed open-hole without fracture stimulation, were to be used to apply a multitude of diagnostics. This, too, was subject to question because of cost, as usual, and doubt about what could be learned that would add to the bottom line. When it comes to our own health, we don’t typically reject recommended diagnostics from experts, even if the results are uncertain or inconclusive. But when it comes to the health of wells and their long-term well-being, applying a suite of multiple diagnostics recommended by those who know best can nevertheless be a very difficult sell.
Past work by the principal authors (Cipolla and McKimmy) showed that ADD laterals, which are naturally substantially less expensive than fully completed and fractured laterals, are actually effective in increasing 365-day pad production and estimated ultimate recovery (EUR). With advancements in drilling in unconventional plays, the next step is employing different options, such as multi-lateral ADD wells or combination dual laterals with one ADD lateral and one PnP lateral. There is a justifiable case to utilize such options for greater production and hydrocarbon recovery.
Advanced diagnostics. But I want to focus more on the use of ADD wells for advanced diagnostics, which are necessary to reach for the much greater potential in unconventional assets, such as the Bakken. There is a tendency in our industry to be satisfied with meeting production and recovery targets associated with asset economic goals, while leaving behind the large majority of original oil and gas in place, some of which is truly recoverable. That is not to mention the obvious potential to simply increase 365-day production and beyond.
The references cited discuss the combination of diagnostics and reservoir and fracturing models on three-well pads. Multiple outside-liner pressure gauges and permanent fiber were used. In addition, micro-seismic mapping of all fracture stages, oil and water tracers to assess fluid entry from each specified zone, and acoustic imaging to assess perforation erosion, were employed. The combination of information from these diverse diagnostic applications was used to calibrate reservoir and fracturing models.
One thing that was determined was that reservoir drainage is typically limited to about 600 ft (or more generally, in the range of 400 to 700 ft). This is due to the practical limits of proppant transport in fracturing operations, regardless of fluid and standard proppant types used. What can be done, based on such findings, is the use of larger proppant volumes and proppant loadings. Smaller-sized proppants and lighter-weight proppants, already trialed in the Bakken on a limited basis, may also enhance drainage distance, if and when a more effective means of including such technologies in job designs can be landed upon.
From the results of the suite of diagnostics in these most recent use cases, the authors suggest that successful field development can be achieved with a lesser number of wells than are currently planned and anticipated. They also believe that EURs can be increased by as much as 25%. There are even more diagnostic opportunities, as advancements are made with tracer deployment methods, and downhole sensors, as examples.
Additional information. I would encourage readers to explore publications regarding ADD completions, objectives, use of associated diagnostics, and subsequent learnings. The two URTeC papers cited are an excellent start, with past references of interest included in each. To reach the next levels of well and field performance, and ultimate oil and gas recovery, it takes risks with new ideas, such as ADD completions, and utilizing combinations of advanced diagnostics to understand fracture patterns, drainage areas, and then applying learnings to future development.
Limitations imposed by budget constraints and general beliefs are natural to our business, but making the effort, backed by sound technology, to break past inherent limitations is what it takes to enable unconventional assets to perform beyond pre-established expectations. WO
LITERATURE CITED
Cipolla, Craig; Michael McKimmy; John Lassek; Khalid Shaarawi (Hess Corporation) Sama Morsy; and Mark McClure (ResFrac Corporation), “Augmented drainage development (ADD) – An evaluation of field development applications in the Bakken,” URTeC paper 4233459, presented at the SPE/AAPG/SEG Unconventional Resources Technology Conference, Houston, Texas, June 9–11, 2025.
McKimmy, Michael; Craig Cipolla; Carlos Miranda; Seth Rudolph; Khalid Shaarawi; Bryan Baca (Hess Corporation),” Case history of drainage mapping and infill well performance in the Bakken,” URTeC Paper 4244595, presented at the SPE/AAPG/SEG Unconventional Resources Technology Conference, Houston, Texas, June 9–11, 2025.
LKALFAYAN@HESS.COM / Leonard Kalfayan has 44 years of oil, gas and geothermal experience. He has worked for Hess, BJ Services, Unocal, and as a consultant. He is an SPE Distinguished Lecturer and Distinguished Member. He has authored numerous publications, including 3 books, and also holds 13 U.S. patents.