This week, we are releasing FracTest, a web-based application for interpretation of diagnostic fracture injection tests (DFITs). FracTest is available at resapps.resfrac.com, alongside our other two ResApps, StageOpt and IntTest. DFITs are small-volume fracture injection
At the 2025 SPE International Hydraulic Fracturing Technology Conference, we (Dontsov, Zoback, McClure, and Fowler) presented “Hydraulic Fracture Propagation Along Bedding Planes Might Be More Prevalent Than We Think” (SPE-226637). The paper reviewed case studies
What controls proppant placement during hydraulic fracturing? As described in Chapter 8 from McClure et al. (2025), ResFrac incorporates a variety of physical processes – viscous drag, gravitational settling, hindered settling, clustered settling, bed slumping,
Horizontal hydraulic fracture propagation is believed to be widespread in shale plays where the frac gradient approaches the overburden – such as the Vaca Muerta, Utica, and Montney. However, horizontal propagation is nearly always ignored
Proppant transport in the well is an intriguing topic that has attracted a lot of interest in recent years [1-8]. Proppant transport processes determine the uniformity of proppant placement, which has a direct impact on
In ResFrac, we are always challenging ourselves—what should we be doing better? What new capabilities should we add to the simulator? One of our newest projects is adding horizontal fracture propagation. Under most conditions, hydraulic
ResFrac Corporation is built around the ResFracPro simulator, which is the only commercial simulator that fully integrates genuine hydraulic fracture modeling and reservoir simulation. Now, we are broadening to build a complementary suite of apps
Below are links to watch two recently recorded talks. The first was a presentation with ThinkGeoEnergy discussing the impressive results from Fervo Energy’s recent Project Red pilot. The second was a presentation with whitson summarizing
This blog post provides practical tips for interpreting Diagnostic Fracture Injection Tests (DFITs) using the ‘compliance method’ procedure initially developed by McClure et al. (2016) and refined in the paper URTeC-2019-123, which summarized results from
To maximize value from an EGS system, we need to optimize flow rate, well spacing, and well configuration. These engineering decisions will make the difference between a money loser and a cash cow. I’ve recently
Hydraulic fractures tend to propagate in a plane that is perpendicular to the least principal stress, as noted by Hubbert and Willis in 1957. As a result, unconventional oil and gas wells are typically drilled
This ARMA Hydraulic Fracturing Community (HFC) presentation summarizes the work on proppant transport in horizontal perforated wellbores. Specifically, it discusses the model for proppant distribution between perforations depending on their orientation and location within the
This is the most exciting time in my lifetime for geothermal. There are many, many innovative things happening. To name a few – promising new approaches to Enhanced Geothermal Systems, geothermal projects in sedimentary and
Simulfrac’s are growing in popularity (see 2021 JPT article for when the trend was just gaining momentum). The idea is that one pumping crew can treat two wells simultaneously versus one well at a time.
This blog post summarizes a new procedure for interpreting interference tests in shale. The full procedure and a detailed writeup are provided by Almasoodi et al. (2023). Interference tests are one of the most effective
Previously, a mathematical model for the problem of slurry flow in a perforated wellbore was described and the underlying physical mechanisms were discussed. The purpose of this blog post, on the other hand, is to
This blog post summarizes the model for calculating proppant distribution between perforation clusters. A very detailed description of the model and literature review are available in [1]. The purpose here is to outline the model
This blog post describes a new capability in ResFrac to capture the effect of ‘fracture swarms’ on production decline trends. Based on work from Acuna (2020), the idea is that variable spacing between fractures causes
Genuine radial flow is rare in shale DFITs. If it does occur, it is typically observed in tests with very low injection volume (less than 10-20 bbl), unusually long shut-in (longer than one week), and
In this post, I will walk through a simple example of using SWPM to calibrate the fracture geometries of a hypothetical data set leveraging the ResFrac Automated History Matching functionality to expedite the workflow. In
ResFrac’s automated optimization tool allows you to quickly and easily identify the economically best well spacing and frac design. This blog post steps through a simple demo of our built-in economics engine that is similar
In this blog post, we review a refracturing and economic optimization case study. The model and history match are loosely based on “SPE Data Repository Well #1,” a publicly available refracturing and production dataset from
Field scale hydraulic fracture simulations reveal a variety of complex fracture geometries. Very often stress interaction between the fractures leads to very asymmetric fracture growth within a stage. At the same time, for some other
This blog post reviews technical opportunities and challenges for next-generation geothermal systems. Multistage hydraulic stimulation, which has been transformative in the oil and gas space, has the potential to create a breakthrough for geothermal energy.
Deep closed-loop geothermal relies on heat conduction to bring energy to the wellbore. Conduction through rock is slow: a fundamental problem that will prevent the concept from ever being economically viable.
In this post, I focus on a particular correlation that is sometimes used in the industry to estimate permeability from a shale DFIT: the ‘holistic permeability correlation.’ I show that this correlation can greatly overestimate
In this post, I go through basic relationships between variables in a pressure match. I discuss some of the strategies that we use for pressure matching, and try to impart intuition into how different physical
DFIT interpretation has been a theme of the work that we’ve done within ResFrac. Our collaborative 2018 Industry Study, which culminated in one of the ‘Best of URTeC’ papers in 2019, developed significant new advances
Shale wells often experience huge production losses after a frac hit. For example, Figure 22 from King et al. (2017) shows a parent well in the Woodford that experienced a 65% reduction in oil production
There has been a lot of controversy over the past five years over how to estimate stress/closure pressure from shut-in pressure transients from Diagnostic Fracture Injection Tests (DFITs). Today, I am reporting on an important
Should we use ‘planar fracture’ models or ‘complex fracture network’ models? Exciting new field data has been published by operators that helps us answer this question, at least for modeling hydraulic fracturing in shale. In this
This post grapples with a complicated, nuanced, and important topic: what do hydraulic fractures look like and how should we model them? Should we use planar fracture models or ‘complex’ hydraulic fracture network models? On
Rate Transient Analysis (RTA) is commonly used to analyze production in unconventional reservoirs. The concept of RTA is to use rate signatures of producing wells to estimate properties such as permeability and fracture surface area.
Typically, hydraulic fracture simulations predict symmetrical propagation away from the wellbore. For example, the figure below shows a ResFrac simulation of fracturing and production in a 200 ft horizontal stage with 50 ft cluster spacing.
Multistage hydraulic fracturing in horizontal wells enables economic production from low permeability resources. A variety of parameters needs to be optimized: stage spacing, cluster spacing, well spacing, well landing depth, injection rate, injection volume per
In this post, I discuss an important new paper, “Sampling a Stimulated Rock Volume: An Eagle Ford Example,” by Raterman et al., which was presented at URTeC in July. This paper is an instant classic
Introduction Back in February, I was at an SPE DFIT workshop where David Craig (one of the vocal advocates of the ‘holistic’ method of picking fracture closure) said that he would have a paper at
In this post, I address a topic that seems esoteric, but it has critical implications for understanding how DFITs respond to closure. In turn, this directly affects how we estimate stress and permeability. The question
“Postclosure” interpretation is used to infer formation permeability from DFIT pressure measurements. As reviewed in previous posts, the goal of a DFIT is to infer formation properties, of which permeability is one of the most
G-function plots are routinely used to interpret diagnostic fracture injection test (DFIT) transients. Ideally, a plot of pressure versus G and G*dP/dG versus G should form a straight line. However, the G*dP/dG curve is very
Diagnostic fracture injection tests (DFITs) are commonly interpreted by plotting pressure versus a function of time called the G-function. The G-function seems rather arcane and is often misunderstood. However, it has a simple, intuitive meaning. In
Aside from the diversity of terminology, the diversity of plotting techniques is the aspect of DFIT analysis that most often causes confusion. Why don’t we just make a Cartesian plot of pressure versus time? There are two
A bewildering variety of terms are used to describe tests in which a small volume of fluid is injected to create a hydraulic fracture: DFIT, leakoff test (LOT), extended leakoff test (XLOT), minifrac test, microfrac
In a diagnostic fracture injection test (DFIT), a relatively small volume of fluid is injected into the subsurface, creating a hydraulic fracture. After the end of injection, the pressure in the wellbore is monitored for
