bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation of Fault Reactivation Using the HISS Model
Authors: Ryu Jenny , Espinoza D. Nicolas , Balhoff Matthew T. , Tavassoli Shayan 
Published: September 2019

Abstract
Long-term integrity and practical storage of CO2 is contingent upon its seal performance and the dynamic sealing capacity of faults for the CO2 storage site. Faults are prone to reactivation with reservoir pressurization caused by CO2 injection. The goal of this study is to create and verify a reservoir elasto-plastic model capable of capturing short-term evolution of fault reactivation and the resulting change of permeability. This model is then used to explore the effects of coupling geomechanics with reservoir fluid flow on the reactivation of faults.
In this paper, we introduce a workflow for modeling of fault reactivation with fault elements as gridblocks instead of surfaces. Reservoir simulation, with coupled fluid flow and geomechanics, was used for this purpose. The simulation models utilize a geomechanical module to capture elasto-plasticity and a compositional numerical scheme based on an equation of state (EOS) to calculate CO2-brine interaction. The geomechanical module used in this study is based on Hierarchical Single Surface (HISS) model that captures strain softening and hardening, and therefore post-yield plastic deformations related to fault reactivation. The compositional numerical scheme based on EOS calculates the amount of CO2 solubilization in brine as well as the density and viscosity of the CO2- and aqueous-rich phase. In this approach, the flow properties, i.e. permeability and porosity, dynamically change in response to geomechanical effects. The dynamic change was captured through a volumetric strain-permeability law.
Our simulation results show that the model is capable of capturing short-term evolution of fault reactivation and the resulting change of permeability along the fault. The dynamic changes of fault properties control the extent of fault reactivation, the pressure relief during injection, and the fault sealing capacity.
Reviving a Mature, Watered-Out Fractured Carbonate Reservoir: An Integrated Approach to Design a Miscible EOR Scheme for the Bigoray Field in Alberta
Authors: Rivero Jose A. , Faskhoodi Majid M. , Mukisa Herman , Zaluski Wade , Ali Lahmar Hakima , Andjelkovic Dragan , Xu Cindy , Ibelegbu Charles , Kadir Hanatu , Sawchuk William M. , Pearson Warren , Ameuri Raouf , Gurpinar Omer 
Published: September 2019

Abstract
The Bigoray area of the Pembina field in western Alberta consists of approximately 50 naturally fractured Nisku carbonate reefs. Production from the Bigoray Nisku D and E pools started in 1978, and shortly after, water injection was initiated to maintain reservoir pressure as a secondary drive mechanism. By 2013, the pools had reached high water cuts, making them uneconomical to produce. In 2017, a decision was made to reactivate the pools and initiate a solvent injection enhanced oil recovery (EOR) project feasibility assessment.
A multidisciplinary team was assembled to review and reinterpret all the geoscience data with modern methodologies to characterize the reservoirs and create new static model descriptions to be used in a dynamic model. Data from well logs, seismic, core measurements, and image logs were integrated into a comprehensive and consistent model that could be used with certainty as a prediction tool.
A history-matching process was carried out by creating different realizations of the static model to honor well-to-well connectivity and water movement within the pools. The history-matching process was performed while ensuring that the model updates were global in nature and consistent with the geological understanding of the reservoirs.
The history-matched model was used to optimize the location of new producers and injectors based on remaining oil saturations and reservoir structure. Optimization of the EOR scheme involved testing a matrix of scenarios to investigate the effect of injection rates and solvent volumes as well as production pressures and voidage ratios. Additionally, in an effort to improve displacement efficiency, a large number of simulation runs were devoted to test and establish the most efficient locations for the well perforations in both the new injectors and producers.
A Semi-Analytical Approach for Analysis of Wells Exhibiting Multi-Phase Transient Linear Flow: Application to Field Data
Authors: Hamdi Hamidreza , Behmanesh Hamid , Clarkson Christopher R. 
Published: September 2019

Abstract
Rate-transient analyses (RTA) is a useful reservoir/hydraulic fracture characterization method that can be applied to multi-fractured horizontal wells (MFHWs) producing from low permeability (tight) and shale reservoirs. In this paper, a recently-developed three-phase RTA technique is applied to the analysis of production data from a MFHW completed in a low-permeability volatile oil reservoir in the Western Canadian Sedimentary Basin.
This new RTA technique is used to analyze the transient linear flow regime for wells operated under constant flowing bottomhole pressure conditions. With the new method, the slope of the square-root-of-time plot applied to any of the producing phases can be used to directly calculate the linear flow parameter, xf√k, without defining pseudo-variables. The method requires a set of input PVT data and an estimate of two-phase relative permeability curves. For the field case studied herein, the PVT model is constructed by tuning an equation of state (EOS) from a set of PVT experiments, while the relative permeability curves are estimated from numerical model history-matching results.
The subject well, a MFHW completed in 15 stages, produces oil, water and gas at a nearly constant (measured downhole) flowing bottomhole pressure. This well is completed in a low-permeability, near-critical volatile oil system. For this field case, application of the new RTA method leads to an estimate of xf√k that is in a close agreement (within 7%) with the results of a numerical model history-match performed in parallel. The RTA method also provides pressure-saturation relationships for all three phases that are within 2% of those derived from the numerical model. The derived pressure-saturation relationships are central to the use of other RTA methods that require calculation of multi-phase pseudo-variables.
The new three-phase RTA technique developed herein is a simple-yet-rigorous and accurate alternative to numerical model history-matching for estimating xf√k when fluid properties and relative permeability data are available.
Reducing Cost of BOE and Extending Field Life with Intelligently Controlled Multilaterals
Authors: Mark Glaser , Andreas Grossmann 
Published: September 2019

Abstract
While many factors in the reservoir cannot be controlled, there are three controllable factors in field development that make a significant impact. More reservoir contact leads to more oil produced. Controlling sand and water means lower treatment costs, and in-situ reservoir management leads to higher cumulative production. While the underlying technologies have been around for up to 20 years, it is only recently that their synergies and true value are understood. This paper will demonstrate the effect each of these technologies has on increasing overall production rates, improving recovery, and reducing the cost per Barrel of Oil Equivalent (BOE).
The successful implementation of multilaterals in the North Sea will be analyzed. Since 1996, over 300 multilateral junctions have been installed on the Norwegian continental shelf fields with currently approximately 30 junctions completed each year.
Additionally, simulations will be used to demonstrate the incremental improvements in oil recovery that can be obtained by using properly designed advanced completions that include multilaterals, sensors, and passive/active flow control equipment.
The paper will evaluate production performance of a vertical well field development base case against scenarios using horizontal and multilateral wells. It will show how fields can be optimized, leading to increased oil and decreased water production.
Production rates can be significantly improved by combining multilaterals with other advanced completion techniques, such as intelligent completions and inflow control devices. The subject field simulation can be further optimized to manage gas and water production.
With a tailored multilateral field design, combined with properly designed advanced completions systems, the simulation succeeds in terms of achieving maximum contact with the oil reservoir and meeting improved ultimate recovery objectives.
It can be concluded that as reservoir contact is increased, a reduced decline in production rate is observed leading to both a higher Estimated Ultimate Recovery (EUR) and optimized drawdown profile distributions. Additionally, results will be presented that have considered oil production and a method to lower production of unwanted fluids or gas.
This paper also demonstrates the value of field development design from the perspective of reservoir simulation. It is through reservoir insight that a level of understanding is created that can help define the optimum well and completion design to meet field expectations.
Advanced multilaterals continue to grow in popularity with many operators, and it therefore becomes important to evaluate the value of different field development methods. This knowledge can aid operators in unlocking new reservoir targets and optimizing field development, and ultimately will improve recovery factors and overall field economics.
Multi-Objective Optimization of CO2 Enhanced Oil Recovery Projects Using a Hybrid Artificial Intelligence Approach
Authors: You Junyu , Ampomah William , Sun Qian , Kutsienyo Eusebius Junior , Balch Robert Scott , Cather Martha 
Published: September 2019

Abstract
In this paper, a hybrid scheme that couples artificial neural network (ANN) and multi-objective optimizers is structured to co-optimize oil recovery and carbon storage of CO2 - EOR processes. The workflow is developed and validated employing an injection-pattern-based model. A field scale case study is presented to demonstrate the practicability of the workflow.
An injection-pattern based reservoir model employing a compositional numerical simulator is established to develop and test the hybrid-optimization workflow. Such a scheme aims at optimizing objective functions including oil recovery factor, CO2 storage and project net present value (NPV). An ANN expert system is trained and employed as a proxy of the high-fidelity model in the optimization process. The ANN model is trained by a robust optimization procedure which is competent to find the best architecture. Particle swarm optimization (PSO) is coupled with the developed proxy model to optimize a weight-aggregated objective function, and multi-objective functions by a Pareto front approach. A field case study is included in this paper. The reservoir model is well-tuned via a rigorous history matching process using the available field data. The aforementioned workflow is deployed to optimize the tertiary recovery stage of the field development.
In this paper, the validation results of the proxy model will be compared against results from the high-fidelity numerical models. Investigations focus on comparing the optimum solution found by the aggregative objective function and the solution repository (Pareto front) generated by the multi-objective optimization process. The optimization results provide significant insight to the decision-making process of CO2 - EOR project when multiple objective functions are considered.
This study develops a novel hybrid-optimization workflow for CO2 - EOR projects considering multiple objective functions. The robustness of the development is confirmed via a field case study. Moreover, this work investigates the relationship between the solutions of the aggregative objective function and the Pareto front, which provides constraints and reduces uncertainties involved by the multi-objective optimization process.
Investigation of Wettability Alteration by Silica Nanoparticles Through Advanced Surface-Wetting Visualization Techniques
Authors: Li Shidong , Dan Daniel , Lau Hon Chung , Hadia Nanji J , Torsæter Ole , Stubbs Ludger P. 
Published: September 2019

Abstract
Altering the wetting state of a rock surface to more water-wet has been proposed as an enhanced oil recovery (EOR) mechanism for nanoparticles. However, how nanoparticles achieve this is not well understood. The objective of this study is to fill this knowledge gap by using advanced 2D and 3D visualization techniques.
In this study, advanced visualization techniques were used to study how hydrophilic silica nanoparticles change the wettability of a glass surface. First, we used interferograms of an oil drop resting on a nanoparticle-treated glass surface to analyze the effect of nanoparticles on wettability. Second, we used Atomic Force Microscopy (AFM) to characterize the structure of nanoparticles covering a glass surface. Third, we used a 2D microfluidic apparatus to visualize wettability alteration caused by the nanoparticle injection. Fourth, we used a fluoresence imaging method with confocal microscopy to find out the reason for this change.
Interferograms of a nanoparticle-treated glass surface showed bright and dark fringes, indicating the presence of a thin water film covering the glass surface caused by nanoparticle adsorption. Furthermore, the higher the nanoparticle concentration, the thicker was the nanoparticle adsorption layer. A low pH environment can reduce nanoparticle adsorption on the glass surface. AFM results showed that the topography of the glass surface changed from smooth to rough after nanoparticle treatment. Microfluidic experiments showed that nanoparticle injection changed the wettability of the grain surface to more water wet. By using a confocal microscopy, we observed a thin water film covering the surface of glass grains suggesting that nanoparticle adsorption is the main mechanism of wettability alteration by nanoparticles.
This paper presents findings of new techniques to study wettability alteration by nanoparticles, including thin-film interferometry, surface characterization by AFM, and fluoresence imaging with confocal microscopy. Observations showed that nanoparticles adsorption on a glass surface results in a thin water film that prevents the oil from contacting the surface. This is the main mechanism of wettability alteration by nanoparticles. This is the first time use of these advanced visualization techniques to study wettability alteration by nanoparticles is reported.
Anticipating Geo-Drilling Hazards by Sharing Geo-Drilling Events Information Nationwide
Authors: Hoetz Guido , Nijhuis Ivo 
Published: September 2019

Abstract
Drilling hazards can lead to significant cost overruns during the drilling phase and might cause unsafe situations or potentially harm the environment. Often the local geology, when poorly understood, is the trigger of a drilling incident. By sharing past drilling experience and in particular observations on Geo-Drilling Hazards, via a suitable platform, well planning and risk assessment can be carried out more effectively. After analysing historic drilling reports, observations on drilling incidents have been compiled using a structured approach. Classification schemes allow systematic capture of key information in a format suitable for a database. In this process the observations (facts) during the drilling operation are analysed and classified into a limited number of event types. By interpreting the data in the geological context, the underlying geohazard type has been determined by selecting from a defined (and limited) number of geological causes. The resulting information can be accessed via an online user interface with GIS functionality and advanced analysis options.
The Geo-Drilling Events (GDE) database currently covers some 1000 boreholes from the Netherlands. Around 1400 geo-drilling events have been analysed systematically allowing to identify drilling hazard hotspots in a statistically meaningful sense. Examples of geo-drilling events include stuck tool, gains, losses, H2S. The underlying geological phenomena i.e. the "geo-drilling hazards" include geological conditions such as: fault, swelling clay, or anomalous pressures. By correlating these with other information, in particular seismic data, the risk of geo-drilling hazards in a planned well can be assessed. For example; it appears that 65% of the (strong) overpressures observed in de Zechstein formation are linked to the Platten dolomite member. This unit can often be identified on seismic and this hazard is therefore, to some degree, predictable.
Planned well trajectories can now be screened efficiently for geo-drilling hazards. The GDE Tool based on advanced classification criteria allows to share relevant well information across all operators active in the Netherlands. This includes newcomers, like geothermal operators who carry out a lot of drilling nowadays. The GDE Tool allows everyone to learn from the experience on drilling hazards gathered over the years by oil companies.
Application of Seismo-Dynamic Analysis to the Development of Oilfields Located in Tectonically Complex Structures
Authors: Salimov Farit , Kotenev Maxim , Kotenev Artem 
Published: September 2019

Abstract
Zones of increased fracture density related to the tectonic disturbances and connected to the protrusions and recesses of the consolidated basement were identified with the application of seismo-dynamic analysis of the seismic data. This is done for the first time on Povkhovskoe oil field located in Western Siberia.
Daily and monthly rates of the producing wells in relation to their location within the geological structure were analyzed. The analysis showed a pattern of increased well productivity by more than 2 times when approaching the areas with high density of fractures. At a distance of more than 500 m from the tectonic disturbances the fluid inflow rates significantly decrease and the performance of hydraulic fracking provides only short-term effect. The deterioration of the reservoir properties is due to a decrease in the value of the reservoir rock permeability because of the decrease in the proportion of fractures and the predominance of the pore space. Reservoir type changes from fractured or fractured-porous reservoir type to porous-only type.
The dependence of high oil saturation of the productive formation from the presence of the tectonic disturbances was recorded. Exploitation of producing wells confirms the assumption of oil moving along the sub-vertical zones of destruction and contributing to the primary target Upper Jurrasic-1 reservoir. Drilling of sidetracks from low oil rate and high water saturation wells in the areas with increased fracture network identified by seismo-dynamic analysis showed a high efficiency of the operations leading to a high-rate production including a substantially lower water-cut oil production (up to 5% of water) at the site where the surrounding production wells have water-cut of 99-100%. Meanwhile, reservoir characteristics of the Upper Jurrasic-1 formation are identical. Based on the results of research identified were prospective deposits for the drilling of production wells on the edges of the hydrocarbon accumulation in areas with high fracture density and suggested were the borehole sidetracks of wells that are plugged and abandoned.
Thus, the detailed structural and tectonic structure of the basement surface and the Jurassic sediments allows to select complex, small-scale geological features, which will be very prospective for the detection of small oil deposits, to specify the location of exploration wells, to start the search for deposits in areas of sub-vertical degradation in the Middle and Lower Jurassic sediments, basement rocks in areas with overlying hydrocarbon deposits already in development. Identifying zones of high density fracturing, including those associated with horizontal shear zones, allows to adjust the contour outlines of the alleged existing deposits and to discover prospective areas with the increased permeability. Described zones and areas are likely to be located close to faults originating in the basement.
Mechanical Properties of Drill Cuttings Based on Indentation Testing and Contact Mechanics Solutions
Authors: Martogi Debora , Abedi Sara , Saadeh Crystal , Mitchell Ian 
Published: September 2019

Abstract
Rock strength evaluation is commonly performed on extracted core samples. The retrieval process of core samples is costly and with high risk, especially in unconventional wells. Besides, mechanical testing carried out on core samples could be time-consuming, particularly for low permeability rocks such as shales. In contrast, tons of shale cuttings are generated and discarded at the end of drilling. Small scale testing, such as instrumented indentation test, could be performed on shale cuttings to obtain the mechanical properties of shale rocks. Unlike core samples, however, the bedding orientation, critical to the definition of mechanical properties of shale cuttings as transversely isotropic material, is indistinguishable on cuttings. A methodology has been developed in the following work to deduce the mechanical properties based on indentation testing of randomly oriented artificial shale cuttings.
Estimation of shale cuttings' elastic constants was carried out using microindentation and constrained inverse algorithm developed based on contact mechanics solutions. Microindentation testing was performed on multiple oriented artificial shale cuttings to obtain the indentation modulus as the function of the unknown bedding orientation. The contact mechanics solutions for both transversely isotropic and anisotropic material were utilized to correlate the indentation modulus to the stiffness tensor components of transversely isotropic shale. An inverse problem was formulated with imposed constraints to identify the mean values of the quantities of interest that best fit the data. The constraints represent the physical information about the bounds on elastic properties as well as a mathematical constraint on the structure of elasticity tensor ensuring the accuracy and robustness of the solutions to this optimization problem. Lastly, Ultrasonic Pulse Velocity (UPV) test was performed to validate the modeling results and good agreement was found between the results of the experimental and modeling efforts and results from UPV tests performed on the same material.
Mechanical properties of shale rocks hold great importance in the design and implementation of drilling and production programs. Retrieval of traditional core samples is known to be expensive and risky as a failure in the recovery process could lead to well abandonment. By using several cuttings with unknown varying bedding orientations, the elastic constants of shales were inferred based on the microindentation testing and the algorithm developed in this work. Successful implementation of this work would allow for a more efficient and economical mechanical characterization of shales.