bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonequilibrium Phase Behavior Plays a Role in Solvent-Aided Processes
Authors: Bayestehparvin Bita , Farouq Ali S. M. 
Published: September 2022

Abstract
Several studies focused on experimental results of nonequilibrium phase behavior and its numerical implementation for solvent-aided recovery processes. However, there is a clear discrepancy between optimistic simulation results and the less than-favorable performance of pilot projects. The intent of the present study is to demonstrate the importance of nonequilibrium phenomena in terms of oil production, steam-oil ratio (SOR), and solvent-oil ratio. This evaluation is based on solvent type, process type, operational conditions, and reservoir properties.
A pore-scale simulator was developed and used to investigate solvent propagation in porous media based on solvent properties (density, viscosity, and diffusion coefficient). Several models were used to investigate the effect of petrophysical properties, e.g. tortuosity, on the upscaled diffusion coefficient, dispersion tensor, and interfacial mass exchange coefficient. In the next step, an in-house thermal reservoir simulator, incorporating nonequilibrium phase behavior, was used to investigate the effect of the particular recovery process.
The butane expanding-solvent steam-assisted gravity drainage (ES-SAGD) process with nonequilibrium assumption leads to a 50% reduction in incremental bitumen production in early stages compared with the result for equilibrium assumption. This number reduces to 20% when the chamber becomes mature. It is shown that lighter and more volatile solvents, such as propane show significant deviation from equilibrium behavior compared to heavier and less volatile solvents. The results for ES-SAGD show that close to the chamber edge or in the cold part of the reservoir, the ratio of nonequilibrium constants to standard K-values is very large which means that solvent/oil system is not at equilibrium. Inside the chamber, the temperature is higher which increases the diffusion coefficient of the solvent. In addition, the contact time for oil and solvent for gridblocks inside the chambers is high enough, so that the nonequilibrium constants are close to the K-values. It was found that nonequilibrium behavior can be diminished by increasing solvent-oil contact time in huff and puff processes.
This study presents a systematic approach to evaluate a given solvent-aided recovery process from the pore to the reservoir scale and provides the guidelines to assess the importance of nonequilibrium phase behavior in both experiments and numerical studies. Based on the findings of this work, the performance of solvent-aided recovery processes can be predicted more realistically, and the process can be optimized for given operating and reservoir conditions and solvent type.
Experimental Investigation of Hydraulic Fracturing on the Montney Formation
Authors: Safari Reza , Albert Richard , Laycock Dallin 
Published: September 2022

Abstract
To assist in understanding the role of rock fabric, stress state, and fracturing fluid viscosity on fracture geometry, four large, dry blocks (28" × 28" × 36") sourced from a Montney formation outcrop were hydraulically fractured in a series of laboratory experiments. These tests investigated the role of texture on hydraulic fracture (HF) propagation with different fluid viscosities, and strike-slip and normal stress regimes. Each block was hydraulically fractured in two stages to allow comparison, within the same overall rock fabric, of fractures created by the different viscosities and injection rates. Pre-existing discontinuities, including calcite-cemented fractures and calcite layers were mapped prior to the test by a goniometer. The static elastic properties, failure parameters, dynamic properties, and fracture toughness of the host rock were measured in detail. During each test, the HF propagation was monitored by recording the generated acoustic emissions. Subsequently, the blocks were carefully dissected, and HF geometries were mapped in detail by laser profilometry.
The results showed that heterogeneity in the rock texture and its location had a primary effect on the fracture propagation. The direction of the maximum stress played, at best, a secondary role. The fracture dynamics determined with acoustic emissions indicated a relatively symmetric, pancake-like shape with high dimensionless viscosity and more asymmetry with low viscosity fluid. Visual inspection of the resulting fractures showed truncated elliptical shapes with both viscosities and with the higher viscosity having less containment. Acoustic emissions clearly indicated HF initiation, propagation, and interaction with the rock fabric, indicating arrest and spreading along pre-existing interfaces in cases of low dimensionless viscosity, and more uniform propagation in cases of high viscosity but with the rock fabric having a significantly reduced impact.
The experiments demonstrated the likelihood of the substantial impediment to successful proppant delivery and hydrocarbon production in the field based on observed occurrences of HF arrest on pre- existing interfaces (indicating possible height containment) as well as the formation of branches and step- overs. Our results indicated that sufficient knowledge of the fabric, in conjunction with proper selection of injection fluid and rates, may provide additional height containment and hence enhance lateral fracture extension and improve the depletion of the pay zone. Ultimately, optimum production may more likely be achieved with collection of further rock samples, laboratory testing, and modeling of pre-existing interfaces to allow relative ranking of these barriers.
Professional Development of a Production & Facilities Generalist as a Jack-of-All-Trades
Authors: Pearson Robert , Brindle George , Anifowose Babatunde 
Published: September 2022

Abstract
This paper looks at the Professional Development of a Production and Facilities (P&F) Generalist ("a Jack-of-All-Trades"). It discusses the criticality of Continuous Professional Development (CPD) and how to take advantage of the SPE Volunteer Opportunities and Programs (Training Services, Competency Development Matrices, and the Competency Management Tool (CMT)).
Most professionals in the SPE Production & Facilities Community graduate with variety of Science, Technology, Engineering and Mathematics (STEM) degrees and many pick up applied Petroleum Engineering and Project Management knowledge on the job.
The SPE Competency Matrices provide a framework for developing:
A minimum Breadth of Knowledge either as an undergraduate or during the first year of employment in the Exploration & Production (E&P) Sector of the Energy Business. A minimum Depth of Knowledge, acquired over the first 4-5 years or so, in General Engineering and their chosen (or assigned) Technical Function, in this case, either Production & Operations (P&O) or Projects, Facilities & Construction (P, F & C).
The mid-career period is often a time of significant turbulence and confusion with many generalists testing-out or being assigned to a variety of roles, such as Subject Matter Experts, Team Leads, Supervisors, and Project Managers, or with other functions and/or new companies before settling on a longer-term career path.
Traditional paths for knowledge development are further complicated by an increased focus on Data Science & Engineering Analysis (DSEA), Sustainability, Decarbonization, and the Energy Transition, along with a need to reinforce our Social License to Operate.
The largest corporations and major training organizations, including the SPE, provide Competency Management Tools to help practitioners identify proficiency gaps and training requirements for a current or anticipated future assignments. Similarly, the SPE provides ongoing support not only with Business Management Leadership (Soft Skills) Training but also through the Technical Communities and Sections. In the final analysis, most P&F Generalists are "value-creation professionals" who just happen to work in the Upstream Oil & Gas Industry and have working knowledge of the acronyms and terminologies typically used in our profession.
Is Smart Water Flooding Smarter Than Seawater Flooding in a Fractured Chalk Reservoir?
Authors: Puntervold Tina , Khan Md Ashraful Islam , Torrijos Iván Darío Piñerez , Strand Skule 
Published: September 2022

Abstract
It is well-known that seawater flooding has been a huge success for hydrocarbon recovery from the fractured chalk reservoir, Ekofisk, on the Norwegian Continental Shelf. Extensive laboratory studies the last decades have shown that Smart Water flooding has potential of greatly improving oil recovery beyond that obtained by standard waterflooding, due to wettability alteration, which improves reservoir sweep efficiency. However, to be economically viable compared to seawater injection, the Smart Water must be cheap, easily available, and must substantially improve oil production. Thus, the objective of this work was to investigate if a tailor-made, but cheap Smart Water could enhance oil production compared to seawater injection in an offshore chalk reservoir. Is seawater the smarter choice in offshore chalk reservoirs?
Two reservoir chalk cores were used in this study and initial reservoir core wettability was estimated from optimized, in-house laboratory core restoration procedures. The potential for wettability alteration and resulting oil recovery by seawater (∼33000 ppm salinity) and Smart Water (&lt;5000 ppm salinity, containing 20 mM SO42-, Ca2+ and Mg2+) were compared in spontaneous imbibition tests at reservoir temperature (&gt;100 °C). Waterflooding at various rates was also performed to evaluate the displacement performance, with regards to water breakthrough and ultimate recovery, of the two injection brines studied.
Reproducible initial wettability was confirmed in both reservoir cores, making a comparison of brine performance easier in spontaneous imbibition tests. The restored cores behaved initially mixed to oil-wet, imbibing limited amount of water. Both seawater and Smart Water showed potential for wettability alteration, although oil recovery by spontaneous imbibition by Smart Water was not improved compared to that by seawater. By low-rate waterflooding the Smart Water was more efficient than seawater due to the water being forced into the interior of the cores causing faster and more pronounced wettability alteration at microscopic scale, hence generating stronger positive capillary forces than in the spontaneous imbibition process. It was concluded that Smart Water flooding can potentially improve recovery beyond that obtained by seawater flooding in fractured chalk reservoirs.
This high-temperature offshore chalk reservoir case study demonstrates that seawater is able to alter wettability of mixed to oil-wet reservoir chalk in a similar way as previously reported for outcrop chalk. Additionally, although seawater injection seems to be a good choice offshore, there is still potential of tailoring a Smart Water composition to both accelerate oil production, delay water breaktrough, increase ultimate oil recovery, thus lowering the field residual oil saturation if its injection is timely implemented.
Improving Alkali Polymer Flooding Economics by Capitalizing on Polymer Solution Property Evolution at High pH
Authors: Födisch Hendrik , Nurmi Leena , Hincapie R. Rafael E. , Borovina Ante , Hanski Sirkku , Clemens Torsten , Janczak Alyssia 
Published: September 2022

Abstract
Alkali Polymer (AP) flooding is a promising Enhanced Oil Recovery (EOR) method to increase oil recovery from reactive oils. It is essential to carefully select the alkali and polymer type and concentration to optimize incremental oil recovery. In addition to the conventional laboratory tests for polymer flooding, the effects of the high pH on the polymer and its evolving properties over time need to be investigated. Consideration of near-wellbore and reservoir effects is a key in designing the process. We are showing how understanding and taking advantage of the polymer performance in a high pH environment allows to reduce costs, increase injectivity and incremental oil recovery for AP projects.
The polymer performance was evaluated for AP flooding of the Matzen field (Austria). Evaluations included changes in polymer rheology during aging at high pH conditions, phase behavior tests, and single/two-phase core floods with aged and non-aged polymer solutions. In addition, adsorption of the aged polymer and interfacial tension was measured. The aging was studied in anaerobic conditions at reservoir temperature and through an accelerated method at elevated temperature. The degree of polymer hydrolysis over time was determined via NMR and linked to viscosity performance.
The AP conditions in the Matzen AP flooding project (pH &gt; 10) lead to an increased initial rate of polymer hydrolysis of the tested HPAM by a factor of 100 compared to hydrolysis at a neutral pH level. This resulted in a rapid increase in polymer solution viscosity of 160 % compared with initial conditions within days at reservoir temperature of 49 °C, after which the increase leveled off. Accelerated aging experiments at higher temperature predict long-term stability of the increased viscosity level for several years. Single-phase injection test in representative core confirmed the performance of the aged solution compared to a non-aged solution at the same polymer concentration. The retention of polymers is reduced in AP conditions compared with traditional neutral pH conditions. Two-phase core flood tests showed the increased polymer viscosity at reservoir conditions. The displacement efficiency of the aged and non-aged polymer solution was similar confirming the potential for cost savings using lower polymer concentration and making use of the increased polymer viscosity owing to hydrolysis.
The results show that the design of alkali polymer projects needs to take the changing polymer rheology with time into account. The costs of alkali polymer projects can be reduced owing to the lower required polymer concentrations for the same displacement efficiency and reduced retention of polymer. An efficient design of alkali polymer projects takes good injectivity of non-aged polymers and the aging of the polymer solutions in alkali into account.
Pioneering Subsurface Data Management Studio and Asset Retirement Obligation Retrenchment in Upstream South Sumatra Region, Indonesia
Authors: Permana Aziz , Sulaksono Aji , Hikmah Nurul , Dwiyono Imam , Pratama Ridho , Gustian Yan , Suseno Pambudi , Parsaulian Sakti 
Published: September 2022

Abstract
According to the geoscientist work profile in Oil & Gas Journal, 1998, inadequate data management practice has caused 60% proportion of the time to be spent for data searching and compilation, it has consequently reduced time for appropriate subsurface analysis. The oil and gas industry in the South Sumatra region is categorized as a matured working area and always becoming a challenge to operate efficiently, not only because of well-developed fields and depleted reservoirs, but also commonly deals with a huge amount of old raw data set, either well coordinates, seismic, trajectory, or log data, even data duplication itself. However, since its first discovery in 1896, the South Sumatra region has already transformed into one of the most productive basins in Indonesia until the present through immense exploration and development activities. Additionally, more than 4000 wells have been drilled in 86 oil fields of the South Sumatra block within an 18,181 km2 working area. Massive operational jobs such as drilling programs, workover, and well intervention involved a lot of subsurface data. Invalid data has proven a serious problem that caused several operational failures and enormous financial losses. Proper implementation of subsurface data management for the last several years has generated significant progress for future company milestones.
A Coreflood Simulation Study of a Systematic Co2 Huff-N-Puff Injection for Storage and Enhanced Gas Condensate Recovery
Authors: Seteyeobot Ifeanyi , Jamiolahmady Mahmoud , Doryanidaryuni Hosein , Molokwu Victor 
Published: September 2022

Abstract
Recently some core flood experimental data were reported following a new CO2 Huff-n-Puff (H-n-P) injection technique. This technique optimized CO2 injection pressure and volume to improve CO2/resident fluid interactions for enhanced gas and condensate recovery and CO2 storage purposes. This simulation study aims to complement and generalize the corresponding core flood experimental results. The simulation data confirm the dominant governing mechanism and the importance of using appropriate CO2/gas-condensate kr data while accounting for the effect of compositional changes on gas and condensate mobility during CO2 H-n-P injection.
Laboratory PVT tests were performed to generate relevant data sets that describe the complex phase behavior changes when CO2 interacts with gas condensate systems. These data sets were applied for EOS tuning, phase behavior prediction, and quantifying the level of CO2/gas condensate interactions. A CO2 H-n-P injection core-flood simulation model was developed. H-n-P injection cycles with the incremental injection of CO2 volumes were simulated to replicate experimental procedures performed on a high-permeability Berea sandstone core.
Experimental data showed that conventional CO2 H-n-P injection treatment significantly improves hydrocarbon gas and condensate recovery efficiency but at the cost of injecting and producing high volumes of CO2. While the proposed method applied at the maximum condensate saturation for the corresponding CO2/gas-condensate mixture can match the recovery efficiency achieved when applying the conventional injection technique, but with much lesser volumes of CO2 injected and produced.
The relative permeability data measured for gas and condensate fluids (GC-kr) were significantly affected by the compositional changes resulting from CO2/resident fluid interactions below the saturation pressure. The numerical model predicted a close match for the pressure profile after adjusting the GC-kr data. However, it could only match the production profile for the pre-CO2 and first CO2 injection cycle, where the volume of CO2 injected was small and had a negligible effect on condensate recovered relative to the volume of condensate in place. Sensitivity analyses were performed on GC-kr data attempting to history match the experimental and simulated data. The generated data were analyzed to quantify the effects of CO2/resident fluid interactions on condensate revaporization and the model's predictability. These data will aid in bridging the gap in the level of CO2/gas-condensate interactions during CO2 flooding, which is vital for designing an efficient CO2 H-n-P injection process.
General Considerations for the Use of Offshore Depleted Reservoirs for CO2 Sequestration
Authors: Amirlatifi Amin , Ovalle Adriana , Bakhtiari Ramezani Somayeh , Mohamed Ibrahim , Abou-Sayed Omar 
Published: September 2022

Abstract
Carbon dioxide (CO2) sequestration is one of the most effective ways of overcoming the excessive emissions of anthropogenic CO2 and the resulting climate change. The existence of large and accessible pore space, along with the wells, pipelines, and surface facilities, makes depleted oil and gas reservoirs a prime target for the deposition of CO2. This study aims to outline the primary considerations for sequestration of CO2 in abandoned oil and gas reservoirs, with a particular focus on offshore reservoirs in the Gulf of Mexico (GOM).
We examine publicly available data from the Bureau of the Ocean Energy Management (BOEM) to gather insight into the existing porous formations in the GOM. Particular interest is given to the formations that have been assessed, developed, and are now abandoned. This approach has enabled us to identify significant storage potentials in shelf, shallow and deep parts of the GOM, making it possible to offer an abundance of safe and long-term storage options in this region.
The first productions in the GOM started back in 1947. As of January 2018, over 900 GOM fields, including more than 5,000 reservoirs (also known as "Sands"), have since ceased production. The total pore volume of these reservoirs is over 175 million cubic feet or over 6.1 million cubic meters. Although many of the wells in these reservoirs are permanently plugged and abandoned (P&A), the existing knowledge about the pore space, the presence of proven seal and geomechanical stability, and the favorable depth of such sands are still highly relevant to commercially viable CO2 sequestration scenarios. Such knowledge can provide a wealth of knowledge, which had to be acquired otherwise prior to the development of the sequestration project.
The present paper offers an overview of the potential CO2 sequestration candidates in the GOM and practical considerations for commercially viable and environmentally friendly sequestration sites. We examine the main factors contributing to the safety and sustainability of long-term storage and sequestration projects, along with remedial techniques that would pave the road for commercial leasing of pore space in the GOM for safe and effective disposal of CO2.
Accelerating Pipeline Corrosion Modeling via Bayesian Active Learning
Authors: Zhang Shun , Lu Ligang , Yang Huihui , Tsai Kuochen , Sidahmed Mohamed 
Published: September 2022

Abstract
Pipeline corrosion poses signiﬁcant challenges and risks to the energy industry and its mitigation requires extensive and reliable predictive modeling. Corrosion models based on computational ﬂuid dynamics (CFD) stands as a desirable candidate for its detailed physical characterization and modeling ﬂexibility, but its applications in practical industrial settings is limited by the high computational cost and laborious manual operation in the modeling and sampling process. To address these challenges, we propose a Bayesian active learning method. The method consists of a surrogate model formulated using Gaussian process regression (GPR) to provide rapid model prediction as well as uncertainty quantiﬁcation, and an adaptive sampling scheme to automate and accelerate the data collection process. Careful dimension reduction guided by both physics and data is also carried out to signiﬁcantly simplify the sampling space. The capability of the overall method for eﬃcient and automated sampling and surrogate modeling is demonstrated on an example case of corrosion predictive modeling and can be leveraged in industrial applications at a much larger scale.