bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integration of Data-Driven Models for Characterizing Shale Barrier Configuration in 3D Heterogeneous Reservoirs for SAGD Operations
Authors: Ma Zhiwei , Leung Juliana Y. 
Published: February 2018

Abstract
Shale barriers may act as flow barriers with adverse impacts on the steam chamber development, as observed in numerous field-scale SAGD projects. Efficient parameterization and inference of such heterogeneities in 3D models from production data remain challenging. A novel workflow for SAGD heterogeneity inference by integrating data-driven modeling and production time-series data analysis is presented.
Variation of shale barriers along the directions between the cross-well pair, as well as of the horizontal wellbore, is considered. Based on a dataset gathered from the public domain, a set of reservoir and operational parameters that represent the typical Athabasca oil sands conditions are extracted to build a 3D homogeneous (base) model. The heterogeneous models are constructed by superimposing shale barriers with varying volume, geometry and locations onto the base model. Production data is recorded by subjecting the generated models to numerical simulation. Input features are extracted from the production time-series data, while output parameters are formulated based on the distribution of shale barriers in the generated models. Data-driven models, such as artificial neural network (ANN), are applied to approximate the non-linear relationships between input and output variables, facilitating the inference of shale characteristics. The final outcome is an ensemble of 3D models of heterogeneity that honor the actual SAGD production histories.
A decline in oil production is observed when the steam chamber encounters a shale barrier. The proposed workflow can capture the observed production patterns effectively. The proposed methodology is demonstrated to be useful for characterizing shale heterogeneities. A testing dataset is used to assess the consistency between model predictions and the target values. In addition, the production responses corresponding to the characterized heterogeneous models are in agreement with the actual responses.
Previous data-driven modeling studies involving 3D heterogeneity inference and SAGD production analysis are limited. The issue of parameterizing a large number of possible heterogeneity descriptions is still challenging. This work presents a preliminary effort to explore this issue. It offers a significant potential to extend most widely-adopted data-driven modeling approaches for practical SAGD production data analysis. The outcomes serve to support the use of data-driven models as complementary and computationally-efficient tools for inference of shale barriers.
Assessment of Methods for Evaluating VIT Thermal Performance
Authors: Damour Jean-Aurelien , Orberg Frederico , Johannson Darren 
Published: February 2018

Abstract
For a completion where Vacuum Insulated Tubing (VIT) is requested, the thermal performance is one of the key parameters to select the fit for purpose product. The heat loss of a VIT string depends not only on the VIT design, but also on external parameters such as effluent and annular fluid temperature and composition, making it difficult to provide the intrinsic thermal performance of the VIT. The industry doesn't have any codes or standards describing a method to evaluate this thermal performance. This paper presents a comparison of the main thermal test methods used by VIT suppliers and operators and sets the limitations of some of these methods. It also proposes a novel method to evaluate VIT thermal performance.
Most thermal tests are realized either on VIT joints in a workshop or on a VIT completion run in a well. The principle is the use of sensors (i.e. temperature gauge, optical fiber or heat flux meter) to provide information on the temperature gradient that could be linked to the heat losses based on some assumptions on the heat exchange coefficient with the external environment. In the study, these thermal test methods are assessed with a finite elements analysis software, which enables the simulation of the different evaluation methods and their comparison by using the same VIT design.
The study stresses how the details of each thermal test procedure and the assumptions made has an impact on the thermal performance it gives. In particular, the location of the sensors or the fluid considered outside the VIT will provide different thermal performance results when varying. A thermal test method is proposed and assessed with the same software in several simulated environments.
This study shows the difficulties to evaluate the VIT thermal performance on the same basis with different factors that could vary, like the test location (inside, outside or in a well), the sensors location and the test conditions (temperature, external fluid being a gas or a liquid). The study also proposes a new thermal evaluation methodology and assesses it with the same criteria used to analyze the main test methods used in the industry.
Longitudinal Dispersion Coefficient in Consolidated Porous Media; A Pore-Level Study
Authors: Mohammadmoradi Peyman , Kantzas Apostolos 
Published: February 2018

Abstract
The fluid flow and transport phenomena are simulated through three-dimensional consolidated and unconsolidated digital rock slabs representing the geological rock types of the McMurray formation. Finite element simulations are carried out in order to solve the mixing advection-diffusion problem, and the effluent history is processed to predict the longitudinal dispersion coefficient and evaluate the efficiency of miscible displacement processes in the presence of microheterogeneities. According to the results, consolidated samples with non-uniform cementation show a different dispersion behavior when compared to both unconsolidated and uniformly cemented rocks, suggesting that the cementation pattern remarkably influences the miscible-flood performance.
Case History-Utilizing Dual Wellhead SAGD in Alshachinskoe Heavy Oilfield in Tartarstan, Russia
Authors: Nukhaev Marat , Rymarenko Konstantin , Latfullin Azat , Amerhanov Marat 
Published: February 2018

Abstract
For decades it has been known that there are several techniques for heavy oil recovery, including traditional Steam Assisted Gravity Drainage (SAGD), cross-well SAGD, single well SAGD, and horizontal alternate steam drive (HASD) etc. The main purpose for these techniques are incresasing efficiency of the SAGD process and controlling steam chamber development.
In this paper, case history will be shared in regards to, implementing for the first time a new method of SAGD techniues in the Alshachinskoe heavy oil field. Based on the results of several trial wells, the proposed dual wellheads SAGD scheme provides the following advantages over traditional SAGD: (1) less risk during drilling and completion phase, (2) more uniform preheating phase provided by several injection points, and (3) more possibility for steam chamber development control during production phase.
As a result the average production for heavy oil was increased from 2 tonnes per day for vertical wells to 24 tonnes per day for dual wellheads SAGD technology (with maximum daily production up to 63 tonnes). The average steam-oil-ratio for dual wellheads SAGD is around 3 (sm3/sm3), that proves high efficiency of the method for steam chamber development and steam trap control over entire period of wells life time.
Feasibility of SAGD as a Follow-Up Process to CSS for a Massive Deep Bitumen Reservoir
Authors: Wu Yi , Wang Zhongyuan , Han Bing , Li Xiaoman , Zhou Guangxing , Wang Ziji 
Published: February 2018

Abstract
Steam Assisted Gravity Drainage (SAGD) is a widely used thermal recovery method for heavy oil and bitumen. S-13832 reservoir in Liaohe oil field in China is reaching economical limit after several cycles of cyclic steam stimulation (CSS). To improve the recovery, toe-to-heel air injection (THAI) had been field tested, however with unfavorable results. In this study, we analyze the alternative SAGD process and show it as most promising follow-up for CSS in S1-3832 reservoir.
We first conduct comprehensive summary of reasons for the previous THAI trial failure, including lack of knowledge for shale layer distributions, difficulties in control spreading of combustion front and blockage of wellbore. Then, numerical simulation has been performed to investigate the feasibility and advantage of using SAGD process in S1-3832. A fine-grid reservoir model with shale layers carefully characterized for reservoir heterogeneity and oil-water distributions modeled. Finally, history match of the field is carried out and dominant influencing factors for SAGD recovery were determined in order to establish an optimum reservoir development strategy.
Vertical injector-horizontal producer and vertical injector-vertical producer hybrid well configuration is adopted in the type pattern simulation model. Key parameters such as perforation locations, steam quality, production-injection ratio, injection rate and SAGD transition time are optimized. It is observed that steam chamber shape is irregular due to the presence of shale layers in some locations. Based on shale layer characteristics of the reservoir, perforation positions together with injection and production rates are adjusted to improve the conformance in these areas. According to these findings, a practical development strategy is designed. Ultimately, the simulation results show the production rate, accumulative oil-steam ratio and other indicators satisfy the requirement of economic development, with incremental recovery factor of 39%in the SAGD stage.
The optimum development plan has been successfully implemented for more than 1 year now, with monitored temperature showing steam chamber growth in favorable manner in the entire reservoir, even in area above shale barriers. With thermal communication achieved, production rate increases progressively, indicating a smooth transition to SAGD mode. This work has demonstrated SAGD as effective recovery process in S1-3832. It also provides technical guidance for designing follow-up processes to CSS for similar reservoirs.
Azeotropic Heated Vapour Extraction- A New Thermal-Solvent Assisted Gravity Drainage Recovery Process
Authors: Khaledi Rahman , Motahhari Hamed Reza , Boone Thomas J. , Fang Chen , Coutee Adam S. 
Published: February 2018

Abstract
Thermal-Solvent Assisted Gravity Drainage processes are heavy oil recovery processes in which the stimulation mechanism for bitumen viscosity reduction is by heating and dilution. The range of the injected solvent concentration with steam may be low such as in Solvent Assisted-SAGD or very high such as in Heated Vapour Extraction. The performance behaviour of these processes is significantly driven by the complex thermodynamic interaction of steam and solvent, heat transfer, multiphase fluid equilibrium and flow in the porous medium.
ExxonMobil and its affiliate Imperial have been optimizing the existing recovery processes and developing new technologies to improve the efficiencies and environmental performance of the heavy oil production operations. Recent focus has been on developing thermal-solvent based recovery processes through an integrated research program that includes fundamental laboratory work, advanced numerical simulation studies, laboratory scaled physical modeling, and field piloting. The research program aims at in-depth investigation and understanding of process physics and mechanisms, and evaluating process performance and behaviour to enable development of new recovery methods and to enhance the performance.
This paper focuses on the fundamental concepts of Azeotropic Heated Vapour Extraction, a new thermal solvent recovery technology developed by ExxonMobil-Imperial. This technology takes the combined advantages of the solvent dilution mechanism for enhanced oil production rate with the minimum required energy (GHG emission), as well as the effectiveness of energy transport of steam to minimize the required solvent in circulation for the extraction process. In this paper, the complex solvent-steam phase behaviour and reservoir fluid flow and their interaction under operating conditions are investigated. The analysis of experimental and modeling data shows that the injection of solvent-steam mixture at its azeotropic condition results in significant improvement in process key performance indicators (KPI's). At these conditions, the reservoir is heated to the minimum boiling temperature of the solvent-steam mixture compared to a Heated VAPEX or Solvent Assisted-SAGD process resulting in the reduction of the required energy thereby minimizing the solvent-to-oil ratio. Also, due to phase equilibrium, the vaporization of in-situ water is prevented resulting in the reduction of retained solvent in the depleted zone of the reservoir. It is found that an improvement in the process KPI's is dependent on the volatility of the selected solvent. The process KPI's also vary with operational conditions. The recovery process is optimized for certain reservoir constraints through the selection of the solvent boiling range and consequently the azeotropic steam content in the injected mixture.
Screening Surfactants for Application in SAGD – Including a Steam-phase Coreflood Test
Authors: Jonasson Ralph G. , Imran Muhammad , Knorr Kelvin D. 
Published: February 2018

Abstract
This research sought to determine whether surfactants and other steam additives can further improve oil recoveries in steam-assisted gravity drainage (SAGD), and to identify plausible mechanisms. It involved extensive experimental study and method development to screen the surfactants suitable for high temperature application and to evaluate incremental improvements in bitumen recovery using surfactants in the gas phase. Formulations of several surfactants were prepared to optimize their properties (e.g., cost, performance, partitioning, water solubility).
The types of surfactants selected for this study were sulfonates and pyrrolidones. These surfactants were pre-screened according to thermal stability in water, interfacial tension (IFT), contact angle, and formation water compatibility. The selected surfactants were tested using the specially designed steam soak apparatus to evaluate the transport of surfactants in the steam phase to the gas/bitumen interface. Linear hot water and steam corefloods in different configurations were also performed to investigate the oil recovery mechanism associated with the use of high temperature surfactants. High-performance liquid chromatography (HPLC) was used to measure surfactant concentrations for thermal stability and coreflood testing.
The steam-soak tests did reveal that combining N-octyl-2-pyrrolidone (NOP) with a sulfonate surfactant, alkyldiphenylethersulfonate (ADPES), could substantially improve oil recovery. This was dispite the fact that sulfonates are not volatile in steam. The hot-water corefloods showed an upward trend in oil recovery with an increase in the N-alkyl-2-pyrrolidone molecular weight and boiling point. The steam corefloods showed the highest recovery for surfactant mixture with 1000 mg/kg NOP and 500 mg/kg ADPES. The post-run core images showed cleaner sand indicating the incremental recovery from the use of surfactant mixture was being achieved by producing the residual oil from the steam chamber. NOP is miscible with bitumen, and is capable of dissolving asphaltenes. However, the viscosity data of oil treated with NOP suggests that viscosity reduction due to surfactant/additive addition is probably not the primary mechanism responsible for improved recoveries. Rather, it can be attributed more towards the IFT reduction, wettability alteration or surfactant dispersion of bitumen in water. No tight bitumen-in-water emulsions were produced in any of the tests.
Produced Water Ammonia Removal using RO Membrane Process
Authors: Chen Cheng , Heimel Sandra , Young Patric 
Published: February 2018

Abstract
This paper presents a novel technology for simultaneous removal of boron and ammonia using two-pass RO membranes for operational cost reduction in produced water treatment. While various conventional technologies exist to remove ammonia from water, they tend to require large capital investments. Examples include ammonia stripping, activated sludge processes, breakpoint chlorination of ammonia, and ion exchange technology. This technology solves a problem of simultaneously removing boron and ammonia from produced water in a cost-effective manner. With the deployment of this technology in Chevron’s San Ardo produced water treatment plant, approximately $1,500,000 in annual OPEX saving is expected while keeping compliance with the plant Waste Discharge Requirement (WDR) permit.
Numerical Simulation of Dielectric Heating in a Heavy Oil Reservoir Using a Shaped Dipole Antenna
Authors: Ovalles Cesar , Vaca Pedro , Okoniewski Michal , Dieckmann Gunther , Pasalic Damir , Dunlavey James 
Published: February 2018

Abstract
The numerical evaluation of dielectric heating in a heavy oil containing sand is presented using a shaped dipole antenna under static (no oil production) and dynamic (with oil production) conditions. The electromagnetic simulator AxREMS™ was coupled to the commercial reservoir simulator STARS™ to model RF heating using three different shaped antenna designs (Straight dipole, Concave, and Convex design). The static simulations showed that the Concave design offers more uniform radiation pattern and temperature profile than the Straight and Convex counterparts. A conceptual model with seven sands (over- and under-burden and five oil-containing sands) was utilized for the dynamic simulation of downhole RF dielectric heating. The results indicated that all the RF heating cases had accelerated oil production than that found for the Base Case (cold production). Modeling shows that peak production is increased if RF heating is initiated before the start of production. However, all cases studied converged to approximately equal cumulative incremental oil above the Base Case, after about 700 days after the initiation of RF heating.
An Experimental Investigation into Sand Control Failure Due to Steam Breakthrough in SAGD Wells
Authors: Mahmoudi M. , Fattahpour V. , Roostaei M. , Kotb O. , Wang C. , Nouri A. , Sutton C. , Fermaniuk B. 
Published: February 2018

Abstract
In Steam Assisted Gravity Drainage (SAGD) projects, it is essential to heat the reservoir evenly to minimize the potential for the localized steam breakthrough. Steam breakthrough can cause erosive damage to the sand control liner by the flow of high-velocity wet steam, and, in extreme cases, can compromise the mechanical integrity of the liner. This research investigates the sanding mechanism during the high-quality steam injection into the SAGD production wells.
A large-scale Sand Retention Test (SRT) was used to investigate the role of steam breakthrough in the sand control performance. Produced sand and pressure drops along the sand-pack were the main measurements during the tests. The test procedure and test matrix were designed to enable the examination of the impact of steam breakthrough on sand production for different steam rates.
Two possible sanding mechanisms are postulated in steam breakthrough events: (1) local grain disturbance caused by the high-velocity steam near the liner, (2) effect of the complex phase behavior of the steam and the subcool level. Two different testing procedures were designed to examine these mechanisms. The local grain disturbance mechanism was investigated by injecting air at a wide range of velocities. Results indicate that this mechanism could not lead to a significant sanding when there is a bit of effective stress near the liner. Hence, it looks like that the steam velocity poses a higher risk in early stages of SAGD production when the near-liner stress is very low. The effect of high-pressure high-temperature (HPHT), low- to high-quality steam flow and the subcool level will be investigated in the next phase of the study. This work addresses the effect of high-quality steam breakthrough on the sand control performance of the liner in SAGD producer wells. The findings in this paper help the researchers to direct their research to better understand the steam breakthrough. This research will eventually help the engineers in their liner design and evaluation for the entire wellbore life cycle as the near-well stress evolves.
Geologically Consistent History Matching of SAGD Process Using Probability Perturbation Method
Authors: Khani Hojjat , Hamdi Hamidreza , Nghiem Long , Chen Zhangxing , Sousa Mario Costa 
Published: February 2018

Abstract
The overall objective of reservoir modeling is to reduce the uncertainty in production forecasts by utilizing all available data to construct a calibrated reservoir model. Geological heterogeneities have a fundamental impact on the growth of a steam chamber and the performance of a SAGD (steam assisted gravity drainage) process. The objective of this work is to incorporate geological heterogeneities into the history matching process using a probability perturbation method (PPM) to preserve the geological consistency of a reservoir model.
A PPM is a geological data integration framework which employs a multiple-point geostatistics (MPS) algorithm. The heart of this method is to systematically perturb the underlying probabilities used to generate the reservoir facies. A PPM generally consists of two loops: an outer loop which is responsible for randomly generating a global configuration of the facies and an inner loop which systematically perturbs the generated facies to match the dynamic data. The combination of these two iterations creates a set of realizations that preserve the geological information.
In this paper, a training image is built based on a 3D outcrop description of a meandering channelized reservoir that is analogous to some of the Canadian heavy oil reservoirs. All other available data including reservoir properties at well locations, trends and production data are also incorporated into the PPM framework for this history matching process. The reservoir model is characterized by three facies: clean sands, medium-grained sandstones and silts, which have different porosity, horizontal permeability and vertical permeability. The SAGD performance is a function of steam chamber development, which depends on the level of heterogeneity in the reservoir. The results show that the heterogeneity distribution has a large impact on the fluid flow at different stages of production. The results show that such complexities can be well preserved during the history matching process using the PPM by generating the geological patterns depicted in a training image. The PPM is shown to be an efficient approach for history matching in presence of complex reservoir geology.