bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Optimization of Catalytic Process In Situ for Heavy-Oil and Bitumen Upgrading
Authors: Shah Amjad A. , Fishwick Robert P. , Leeke Gary A. , Wood Joseph , Rigby Sean P. , Greaves Malcolm 
Published: June 2014

Summary
The worldwide conventional crude-oil demand is on the rise, and because of the rising prices, unconventional oils are becoming more economically attractive to extract and refine. However, technological innovation is needed if heavier oil supplies are to be exploited further. Toe-to-heel air injection (THAI) and its catalytic add-on processes (CAPRI) combine in-situ combustion with catalytic upgrading using an annular catalyst packed around the horizontal producer well. These techniques offer potentially higher recovery levels and lower environmental impact than alternative technologies (e.g., steam-based techniques). An experimental study is reported concerning the optimization of catalyst type and operating conditions for use in the THAI-CAPRI process. The feed oil was supplied from the Whitesands THAI-pilot trial. Experiments were carried out using microreactors containing 10 g of catalyst, with oil flow of 1 mL/min and gas flow of 0.5 L/min, under different temperatures, pressures, and gas environments. Catalysts tested included alumina-supported CoMo, NiMo, and ZnO/CuO. It was found that there was a trade-off in operation temperature between upgrading performance and catalyst lifetime. At a pressure of 20 bar, operation at 500°C led to an average of 6.1°API upgrading of THAI oil to 18.9°API, but catalyst lifetime was limited to 1.5 hours. Operation at 420°C was found to be a suitable compromise, with upgrading by an average of 1.6°API, and sometimes up to 3°API, with catalyst lifetime extended to 77.5 hours. Coke deposition occurred within the first few hours of the reaction, such that the catalyst pore space became blocked. However, upgrading continued, suggesting that thermal reactions or reactions catalysed by hydrogen transfer from the coke itself play a part in the upgrading reaction mechanism. The CAPRI process was relatively insensitive to changes in reaction-gas medium, gas-flow rate, and pressure, suggesting that the dissolution of hydrogen or methane from the gas phase does not play a key role in the upgrading reactions. By careful control of the temperature and oil-flow rate in the in-situ CAPRI process, additional upgrading compared with the THAI process alone may be effected, resulting in a more-valuable produced oil, which is easier to transport.
Analyzing Production Data From Unconventional Gas Reservoirs With Linear Flow and Apparent Skin
Authors: Nobakht Morteza , Mattar Louis 
Published: June 2014

Summary
Many horizontal wells with multiple fractures producing from unconventional gas reservoirs have been observed to exhibit linear flow. Often it is the only flow regime, and it can last several years. Classically, this flow regime is characterized by a half slope on type curves when there is no skin effect. However, most of the time, a skin effect is observed in these wells (caused by flow convergence or finite conductivity in the fractures).
The presence of skin changes the shape of data points when plotted on log-log scales, and this can have a huge effect on the interpretation when using type curves. For example, a well with purely linear flow and with skin in a reservoir that is infinite acting may appear like and be interpreted as a finite-acting reservoir simply because of the skin effect.
This paper discusses different methods that can be used to eliminate the misinterpretation caused by the presence of skin when analyzing linear flow by use of type curves. First, it is shown that among all the derivative and integral functions that are currently used, only well-test-style semilog derivative (DER) and pressure integral-derivative are not affected by the skin. However, these two functions have other issues that usually make them unfit for use in production-data analysis. DER is noisy most of the time, and the process of integration often introduces errors at early times that can significantly distort the shape of the pressure integral-derivative. Therefore, an easier method is presented to analyze the production data from shale gas reservoirs with extended periods of linear flow and significant skin. This method uses the square-root-of-time plot to remove the apparent skin effect from the data. Then, the data (excluding skin) are used for type-curve analysis. This simple procedure prevents potentially significant misinterpretation.
First-Contact-Miscible, Vaporizing- and Condensing-Gas Drive Processes in a Channeling Heterogeneity System
Authors: Al Wahaibi Y. M. , Al Hadhrami A. K. 
Published: June 2014

Abstract
Experimentally measured recoveries, gas cuts and residual saturations as well as the visual observations were used to quantify the effects of channeling heterogeneity system on efficiency and gas/oil nonequilibrium of first- and multi-contact miscible (MCM) displacements. These experiments are the first of their kind as they have enabled a direct insight into the mechanisms of gas/oil flow occurring within such type of heterogeneities, and particularly have provided a firmer understanding of the MCM processes.
The key finding in this work is the fact that the produced fluids in all MCM experiments were not in compositional equilibrium. The effect of channeling heterogeneity was to lower mass transfer between oil and MCM gas phases throughout the porous medium as a whole, thereby driving the system to be more sub-miscible and as such reducing the sweep and increasing the bypassing. These results were also reflected in the increase in nonequilibrium between gas and oil phases. This work has proved that the channeling heterogeneities, even with small permeability contrast, can distort first- and multi-contact miscible displacement patterns considerably.
Additionally, the results suggested that the performance of MCM processes decrease significantly with the increase in injection rate. This was probably due to an interplay between capillary and viscous forces in the heterogeneous model causing the gas at highest rate to flow faster into the high permeability stripe, and therefore resulting in a larger transition zone, shorter miscibility region, higher nonequilibrium and hence a lesser efficient flood.
This study has important implications for the correct interpretation of core data, and for scale-up processes to reservoir scale, particularly for handling gas/oil nonequilibrium when modelling MCM displacements.
Integrated Geodynamic Monitoring and Risk Assessment of Occurrence of Seismic Deformation Processes Related to Development of Raw Hydrocarbon Deposits
Authors: Shevelyova A.. 
Published: June 2014

AbstractThe Karachaganak field is a large onshore gas-oil-condensate accumulation with initial hydrocarbons in place of approximately 9 billion barrels of condensate and more than 45 trillion cubic feet of gas. The Karachaganak structure is a carbonate massif that comprises a heterogeneous reef and platform carbonate complex measuring 30 km by 15 km.Geodynamic events of natural and man-induced genesis occurring during the development of hydrocarbon fields attract considerable attention from both the general public and engineering specialists alike. This paper highlights the necessity of geodynamic monitoring in the course of a hydrocarbon field development and describes the status of geodynamic monitoring in the Karachaganak field located in West Kazakhstan Oblast.Lack of control over geodynamic events of natural and man-induced genesis can lead to irreversible consequences (induced earthquakes in USA, Canada and other countries), that can be damaging to the environment, and costly to remediate. Identification, prognosis and prevention of such consequences are fundamental tasks of the geodynamic monitoring in the course of development of hydrocarbon fields. Therefore, the task of monitoring geodynamic processes during the development of oil and gas fields draws special attention from operating companies and government authorities.Implementation of geodynamic monitoring prior to commencement of and during commercial field development is a mandatory requirement of the RoK legislation. A primary purpose of geodynamic monitoring is to ensure environmental safety by taking necessary measures to mitigate and prevent a risk of occurrence of uncontrolled events associated with geodynamic processes during and after field development.In Karachaganak field the monitoring over geodynamic processes began in 2002 by initiating a local seismological monitoring program which continued until the end of 2007. In 2008 a programme of integrated geodynamic monitoring was developed. Implementation of the programme, which envisages application of such methods as levelling, gravimetric and GPS surveys, and seismological monitoring, will allow the operator to thoroughly study geodynamic processes in Karachaganak field.In June of 2009 a benchmark survey was conducted, and as more data from repeat surveys becomes available, it will be possible to investigate patterns and temporal development of geodynamic processes such as an activation of faults, compaction and lateral displacements of rock masses, surface subsidence, and seismicity.
Application of Artificial Intelligent Systems in ROP Optimization: A Case Study in Shadegan Oil Field
Authors: Bataee M.. , Mohseni S.. 
Published: June 2014

Abstract
According to the field data, there are several methods to reduce the drilling cost of other wells. One of these methods is the optimization of drilling parameters to obtain the maximum available ROP. Considering the geology and rock mechanic parameters, each part of well has different recommended parameters.
There are too many parameters affecting in rate of penetration like hole cleaning (including drillstring rotation speed, mud rheology, weight on bit and floundering phenomena), tooth wear, formation hardness (including depth and kind of formation), differential pressure (including mud weight) and etc. Therefore, developing a logical relationship among them to assist in proper ROP selection is extremely necessary and complicated though. In such a case, Artificial Neural Networks (ANNs) is proven to be helpful in recognizing complex connection between these variables. Genetic Algorithm (GA), as a class of optimizing methods for the complex functions, is applied to help ROP optimization and its related drilling parameters. Optimization program will optimize drilling parameters which will be used in future works and also leads us to proper time estimation. The present study is predicting the proper penetration rate, optimizing the drilling parameters, estimating the drilling time of well and eventually reducing the drilling cost for future wells.
Asset Integrity Key Performance Indicators - A Cross Industry Approach
Authors: Paterson Robert 
Published: June 2014

Abstract
This paper follows the identification, development and evolution of two, asset integrity related key performance indicators (KPI) for the UK offshore industry. Both indicators relate to differing aspects of the status and condition of safety critical plant and equipment on the installation. Data covering 99% of UKCS offshore installations since the beginning of 2008 is covered. Next steps for further development of these KPIs are outlined, together with key lessons for others wishing to set up and develop other whole industry performance indicators
Proper Design of Polymer-Based In-Situ Gelled Acids to Improve Carbonate Reservoir Productivity
Authors: Gomaa Ahmed M. 
Published: June 2014

Abstract
Lab test of polymer-based in-situ gelled acids reveal that polymer and other additives separate out of the acid when these acids are prepared in high salinity water. In coreflood tests, in-situ gelled acid formed a gel inside 20". long core samples, and the acid changed its direction several times. Unexpectantly, the core's permeability was reduced at low shear rate. Wormhole length increased as the shear rate was increased, while the diameter of wormhole increased as the acid cumulative injected volume was increased. CT scan indicated the presence of gel residue inside the and around the worm hole. Gel residue increased at low shear rates. Material balance on the cross-linker indicated that a significant amount of the crosslinker was retained in the core.
Based on the results obtained from this study the in-situ gelled acids should be used only at low HCl concentrations (5 wt% HCl). Acid should be prepared in low salinity water. Acid injection rate should be determined based on the expected shear rate in the formation. A core flood experiment is recommended to confirm optimum injected rate. Flow back the well to minimize the residual gel inside the formation. The data obtained in our study can be used as a guideline for injection rate selection.
Interfacial Areas and Immiscible Fluid Structures of Oil and Water in Oil-Wet and Water-Wet Porous Media
Authors: Landry Christopher James 
Published: June 2014

ABSTRACT
The objective of this study is to obtain quantitative evidence of pore-scale immiscible fluid distribution in oil-wet and water wet porous media using x-ray computed microtomography. Temporal and spatial saturation profiles, as well as surface and interfacial areas are thoroughly analyzed through cycles of drainage and imbibition using samples with different wetting characteristics but similar pore structures. Furthermore, the population of individual immiscible fluid structures (blobs') is also evaluated. The specific non-wetting phase surface areas of both porous media are found to be in close correlation with the specific solid surface area. On the other hand, the differing wetting strengths of the two porous media affects the fluid fluid interface, and thus the specific meniscus interfacial area of the two porous media. The specific meniscus interfacial area trends towards a maximum at wetting phase saturations of 0.35–0.55 for both porous media. The saturation of the maximum specific meniscus interfacial area is that of the greatest fluid-fluid interaction. The differences in wetting characteristics are also apparent in the blob populations. The number of blobs in the oil-wet porous media is three times greater than that of the water-wet porous media at similar saturations; the increase in population is due to the increase in the amount of smaller blobs being found in the more weakly-wetting oil-wet porous media, a result of lacking wetting-phase dominance in the smaller pore spaces. The surface areas of individual blobs as a function of the individual blob volumes are found to closely agree with that of a sphere at blob volumes below the minimum individual grain volume, and with the specific pore space surface area above this volume. These results show how the pore space geometry, wettability and saturation history influence the distribution of immiscible fluids within the pore space; these general observations can be a powerful resource for the improvement of multiphase fluid flow property prediction, properties such as relative permeability and capillary pressure.
Development of a Predictive Model for Carbon Dioxide Sequestration in Deep Saline Carbonate Aquifers
Authors: ANBAR Sultan 
Published: June 2014

Abstract
Increase in CO2 concentration in the atmosphere is the widespread concern due to its global warming effect. CO2injection into deep saline aquifers is one of the preferable ways to mitigate the CO2 emission since CO2 is in supercritical state and larger volumes of CO2 can be stored due to its high density. Several numerical simulations are needed before injection to determine the storage capacity of a saline aquifer. Since numerical simulations are very expensive and time consuming, developing a predictive model can be very useful to quick estimation of CO2storage capacity of a deep saline aquifer.
To create a predictive model, ranges and limits of rock properties (porosity, permeability, vertical to horizontal permeability ratio), fluid properties (irreducible water saturation, gas permeability end point, Corey water and gas exponents), reaction properties (forward and backward reaction rates) and reservoir properties (depth, pressure gradient, temperature gradient, formation dip angle, salinity), diffusion coefficient and Kozeny-Carman Coefficient that affect the CO2 storage capacity are determined from published literature data. Other parameters such as pore volume compressibility and density of brine are calculated from correlations. To cover all possibilities, Latin Hypercube Space Filling Design is used to construct 100 simulations developed using CMG STARS for 300 years of CO2 injection. By using least squares method, a linear correlation with a correlation coefficient 0.81 is found to calculate CO2 storage capacity of the deep saline carbonate aquifers by using aforementioned simulation variables. Numerical dispersion effects have been considered by increasing the grid dimensions. It has been found that correlation coefficient decreased to 0.78 when the grid size was increased from 250 ft to 750 ft. The sensitivity analyses showed that the most important parameter that affects CO2 storage capacity is depth since the pressure difference between formation pressure and fracture pressure increases with depth. It was observed that most of the gas (up to 90%) injected into the aquifer formation dissolves into the formation water and negligible amount of CO2 reacts with carbonate. This result is in accord with sensitivity analyses as the variables affecting the solubility of CO2 in brine have greater affect on storage capacity of aquifers. Dimensionless linear and nonlinear predictive models were constructed to estimate the CO2 storage capacity of a deep saline carbonate aquifer and it was found that the best dimensionless predictive model is a linear model that is independent of bulk volume of the aquifer.
Pulse Testing for Enhanced Reservoir Characterization of the EOR Pilot Area in Mangala Field
Authors: Jha Manish Kumar , Pandey Amitabh , Tandon Rohit , Beliveau Dennis 
Published: June 2014

Abstract and Introduction
Mangala is a large oilfield in northwestern India containing significant volumes of moderately viscous paraffinic crude oil. The base field development plan is a hot waterflood, but due to the adverse mobility ratio between injected water and in situ oil, large volumes of water will be produced overlife along with the oil. As a result, the Operator has been examining EOR options since the field discovery in 2004, with aqueous-based chemical processes being the preferred way forward.
Oil production began in August 2009, quickly followed by startup of the water injection system in January 2010. Currently, the field is producing 125,000 bopd with injection of 140,000 bwpd. Since the Operator envisages early field-scale implementation of chemical EOR, a closely-spaced eight-well polymer-ASP flood pilot was constructed during 2010. Pilot water injection began in December 2010, less than a year after the field-scale waterflood startup.
The foundation for the analyses of any EOR pilot is appropriate reservoir characterization, and all efforts are being made to ensure that right data is collected in the Mangala EOR pilot. A key aspect of the reservoir characterization program involves multi-well pulse tests which are described in this article.
Experimental Investigation of In-Situ Combustion at Low Air Fluxes
Authors: Alamatsaz Alireza , Moore R. Gordon , Mehta Sudarshan A. , Ursenbach Matthew G. 
Published: June 2014

Summary
The oil industry has inherited a mixed history of success and failure of application of air injection as an enhanced-oil-recovery method. Close scrutiny of these projects shows that in order to conduct a successful in-situ-combustion-oil-recovery project, sustained propagation of the combustion front within the reservoirs is necessary. Sufficient air must be supplied to maintain the propagating combustion front in the desired bond-scission (carbon-oxide-forming) mode, otherwise unfavourable oxygen addition [i.e., low-temperature-oxidation (LTO) reactions] will consume oxygen and immobilize oil. When this happens, the combustion process is deemed to be exhausted.
Quantification of the minimum air flux required for sustaining combustion-zone propagation is needed to properly match the capacity of the air-injection facility to the volume of the reservoir that is to be swept by the thermal zone. Undersizing the air-injection capacity causes the in-situ-combustion process to become inefficient at a point when only a small portion of the reservoir has been "burned."
One-dimensional combustion tubes (CTs) are conventionally used to obtain important combustion parameters required for designing an air-injection project. Because of the high heat capacity of laboratory equipment designed for elevated-temperature and -pressure operation, oxygen addition or LTO reactions are promoted by the heat transfer through the core-holder walls when the laboratory tests are performed at low air-injection rates. Therefore, when operated at elevated pressures, the CTs are unable to operate at the low air fluxes required to establish the minimum possible air-injection flux while maintaining the combustion reactions in an effective mode.
To address this issue, a state-of-the-art combustion cell was conceived and used as a way of addressing the previously mentioned constraints associated with high-pressure 1D CTs. A conical combustion-cell design was built because it enables continuous air-flux reductions without having to adjust the air-injection rate. The heater control strategy was also modified in order to address the lag-lead operation often used for 1D CTs. To date, the unit has operated at air fluxes down to 3 std m3/m2•h.
The experimental work described in this paper provides insight into the limitations in laboratory investigations of in-situ combustion and the expected behaviour of field applications of the in-situ-combustion process.
Acoustic-Wave-Testing System for Monitoring the Vapour Chamber in Vapour-Extraction Process
Authors: Zhou Wenjin , Paranjape Raman , Asghari Koorosh 
Published: June 2014

Summary
The acoustic-wave-detection system is considered a nondestructive monitoring system to estimate distances by measuring the time-of-flight of an ultrasonic wave. In this paper, a comprehensive experimental study was conducted to investigate the feasibility of the acoustic-wave-detection system in monitoring the shape and position of the gas phase in the vapour-extraction (VAPEX) process. For this purpose, various stages of vapour-chamber evolution in the VAPEX process were simulated experimentally by changing the shape of air balloons buried in simulated porous media in a laboratory-scale model. Then, an array of ultrasound transducers and receivers was used to measure time of flight at different stages of the vapour-chamber growth. Finally, the collected data were fed into a signal-processing program developed in this study to determine the shape of the vapour chamber. Conducted analysis in this study includes sound-speed testing in different porous media, signal-attenuation tests in different porous media, imaging of different simulated vapour chambers in different porous media, and acquisition and analysis experiments. Results show that acoustic-wave detection can be used for accurate mapping of the position and shape of the vapour chamber in the studied process. Monitoring the shape and growth of the vapour chamber provides valuable information for optimizing oil production in order to maximize oil recovery. The proposed methodology is able to identify acoustic anomalies in a porous medium in the laboratory.