Preprints
Filtering by Subject: Petroleum Engineering
Rate-Controlled Porosimetry: A State-of-the-Art Review
Published: 2023-11-21
Subjects: Petroleum Engineering
Rate-controlled porosimetry is a powerful technique for studying the pore structure of porous media and the physical properties of porous media. This technique involves injecting and extracting a non-wetting fluid at a controlled rate into and from a porous medium, resulting in a fluctuating capillary pressure trace as a function of the injected non-wetting fluid volume. This review introduces [...]
The interactions of instabilities during miscible CO2 enhanced oil recovery: A numerical simulation study
Published: 2023-07-13
Subjects: Petroleum Engineering, Transport Phenomena
During field-scale simulations of miscible displacements, the effect of heterogeneity-induced channelling is always accounted for, while micro-scale physical instabilities like viscous fingering and molecular diffusion are ignored due to the computational costs of the required fine-grid simulations. Thus, the interplay between small- and macro-scale physical instabilities is not properly [...]
Laboratory validation of a new hydro-mechanical energy-based brittleness index model for hydraulic fracturing
Published: 2022-12-01
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Engineering Science and Materials, Mining Engineering, Oil, Gas, and Energy, Petroleum Engineering
Brittleness Index (BI) is a critical parameter characterising the deformation regime of geo-materials, covering the range from purely brittle (fractures) to ductile (plastic flow). A variety of BI models have been developed based on rock properties such as mineralogy, elastic parameters, or stress-strain data. However, very few of them are based on the deformation induced by hydro-mechanical [...]
Hydraulic fracturing: Laboratory evidence of the brittle-to-ductile transition with depth
Published: 2022-05-14
Subjects: Earth Sciences, Engineering, Geology, Petroleum Engineering
Understanding the propagation of hydraulic fracture (HF) is essential for effectively stimulating the hydrocarbon production of unconventional reservoirs. Hydraulic fracturing may induce distinct failure modes within the formation, depending on the rheology of the solid and the in-situ stresses. A brittle-to-ductile transition of HF is thus anticipated with increasing depth, although only scarce [...]
Economic Analysis of CCUS: Accelerated Development for CO2 EOR and Storage in Residual Oil Zones Under the Context of 45Q Tax Credit
Published: 2022-04-07
Subjects: Earth Sciences, Petroleum Engineering
Residual oil zones (ROZ) undergoing CO2-EOR may benefit from specific strategies to maximize their value. We evaluated several strategies for producing from a Permian Basin, West Texas, USA field’s ROZ. This ROZ lies below the main pay zone (MPZ) of the field. Such brownfield ROZs occur in the Permian Basin and elsewhere. Since brownfield ROZs are hydraulically connected to the MPZs, development [...]
Complex multi-source emissions quantification results for the PoMELO vehicle measurement system, test results from the CSU METEC facility
Published: 2022-03-17
Subjects: Atmospheric Sciences, Operations Research, Systems Engineering and Industrial Engineering, Other Engineering, Petroleum Engineering, Systems Engineering
Methane emissions from oil and gas sites are often characterized by mixed plumes from multiple sources in close proximity. This presents a challenge for screening methods that rely on emissions quantification to direct and prioritize follow-up inspections. Here, we present results from experiments evaluating mixed-source quantifications using the University of Calgary Portable Methane Leak [...]
Fluid invasion dynamics in porous media with complex wettability and connectivity
Published: 2021-06-18
Subjects: Chemical Engineering, Complex Fluids, Earth Sciences, Fluid Dynamics, Hydrology, Materials Science and Engineering, Other Materials Science and Engineering, Petroleum Engineering, Transport Phenomena
Multiphase flow is important for many natural and engineered processes in subsurface geoscience. Pore-scale multiphase flow dynamics are commonly characterized by an average balance of driving forces. However, significant local variability in this balance may exist inside natural, heterogeneous porous materials, such as rocks and soils. Here, we investigate multiphase flow in heterogeneous rocks [...]
The Paradox of Increasing Initial Oil Production but Faster Decline Rates in Fracking the Bakken Shale: Implications for Long Term Productivity of Tight Oil Plays
Published: 2020-10-21
Subjects: Oil, Gas, and Energy, Petroleum Engineering
In the US, tight oil is the largest source of liquid hydrocarbons and has driven the country to become the world’s largest oil producer. Eventually many countries will likely be producing very large quantiles of tight oil. However, how robust is tight oil production? The answer to this question will have an impact on the future geographic spread of oil production and will have geopolitical [...]
Three Common Statistical Missteps We Make in Reservoir Characterization
Published: 2020-05-12
Subjects: Chemical Engineering, Earth Sciences, Engineering, Geology, Petroleum Engineering, Physical Sciences and Mathematics, Statistical Methodology, Statistics and Probability
Reservoir characterization analysis resulting from incorrect applications of statistics can be found in the literature, particularly in applications where integration of various disciplines is needed. Here, we look at three misapplications of ordinary least squares linear regression (LSLR) and show how they can lead to poor results and offer better alternatives, where available. The issues are [...]
Comparison of permeability predictions on cemented sandstones with physics-based and machine learning approaches
Published: 2020-02-06
Subjects: Chemical Engineering, Earth Sciences, Engineering, Hydrology, Multivariate Analysis, Petroleum Engineering, Physical Sciences and Mathematics, Statistics and Probability
Permeability prediction has been an important problem since the time of Darcy. Most approaches to solve this problem have used either idealized physical models or empirical relations. In recent years, machine learning (ML) has led to more accurate and robust, but less interpretable empirical models. Using 211 core samples collected from 12 wells in the Garn Sandstone from the North Sea, this [...]
Fluid surface coverage showing the controls of rock mineralogy on the wetting state
Published: 2019-12-13
Subjects: Chemical Engineering, Earth Sciences, Engineering, Petroleum Engineering, Physical Sciences and Mathematics
The wetting state is an important control on flow in subsurface multi fluid phase systems, e.g., carbon storage and oil production. Advances in X-ray imaging allow us to characterise the wetting state using imagery of fluid arrangement within the pores of rocks. We derived a model from equilibrium thermodynamics relating fluid coverage of rock surfaces to wettability and fluid saturation. The [...]
Dynamic modelling of overprinted impermeable fault gouges and surrounding damage zones as lower dimensional interfaces
Published: 2019-11-15
Subjects: Chemical Engineering, Civil and Environmental Engineering, Computational Engineering, Engineering, Petroleum Engineering
In the modelling of subsurface fluid flow, faults are dominant features since they can act as fluid pathways or barriers. Special emphasis is therefore placed in representing them in a numerically efficient manner and the use of lower dimensional domains has become prevalent to simulate higher permeability features like fractures. Such features, however, only represent some of the components of [...]
Three-scale multiphysics finite element framework (FE3) modelling fault reactivation
Published: 2019-11-11
Subjects: Chemical Engineering, Computational Engineering, Engineering, Petroleum Engineering
Fluid injection or production in petroleum reservoirs affects the reservoir stresses such that it can even sometime reactivate dormant faults in the vicinity. In the particular case of deep car- bonate reservoirs, faults can also be chemically active; chemical dissolution of the fault core can transform an otherwise impermeable barrier to a flow channel. Due to the scale separation of the fault [...]
The sensitivity of estimates of multiphase fluid and solid properties of porous rocks to image processing
Published: 2019-10-11
Subjects: Chemical Engineering, Civil and Environmental Engineering, Earth Sciences, Engineering, Hydrology, Petroleum Engineering, Physical Sciences and Mathematics, Transport Phenomena
X-ray microcomputed tomography X-ray microCT) is a rapidly advancing technology that has been successfully employed to study flow phenomena in porous media. It offers an alternative approach to core scale experiments for the estimation of traditional petrophysical properties such as porosity and single-phase flow permeability. It can also be used to investigate properties that control multiphase [...]
Imbibition in porous media: correlations of displacement events with pore-throat geometry and the identification of a new type of pore snap-off
Published: 2019-08-23
Subjects: Chemical Engineering, Civil and Environmental Engineering, Complex Fluids, Dynamics and Dynamical Systems, Engineering, Engineering Science and Materials, Environmental Engineering, Materials Science and Engineering, Mechanics of Materials, Petroleum Engineering, Transport Phenomena
The displacement of a non-wetting fluid by a wetting fluid in porous media, called imbibition, is important in many natural and industrial processes. During imbibition, the wetting fluid invades the pore space through a series of competitions between piston-like displacement, film and corner flow, snap-off, pore bypassing and trapping. Our understanding of these fundamental pore-scale [...]