bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study in Quantifying Thin-Bedded Pay Contribution Within a Deltaic System in the Columbus Basin
Authors: Fortune Jochelle , Jackman Randell 
Published: June 2018

Abstract
The objective of this study was to systematically and quantitatively quantify where production from Thin – Bedded Pay may be more challenging using conventional methods of completion. This study will focus on different areas within the deltaic environment in which Thin – Bedded Pay are prominent. A 3D structural model was built and populated with properties to represent four (4) different main classes of geological environments with a deltaic system. It explored the effect of completing across the conventional sands only vs completing both the conventional and secondary units. The main finding in this thesis is that completing the thin-bedded pay increased the overall rate of the production on average of about 10% in different environments. In addition, in complicated reservoir architecture environments such as the upper slope and distal delta slope environments, there are significant (14% and 10%) incremental increases in the recovery factors by completing across these thinly bedded zones. Thus, it is recommended that these environments be further explored in how best to develop the thin-bedded resource in these environments since, in a time when the finite resources of oil and gas are becoming scarce, it is important to understand what reserves we may have that are not currently being tapped into.
Application of the Capacitance Model in Primary Production Period before IOR Implementation
Authors: Soroush Mohammad , Rasaei Mohammad Reza 
Published: June 2018

Abstract
Injection and production historical data are easily accessible and using them does not incur the costs of running field tests. The capacitance model (CM), an analytical model based on injection and production data, has recently been applied successfully in several field cases. The CM has two outcomes, rate prediction and well to well connectivity evaluation and primarily derived for waterflood period. This paper modified this model for primary production period.
The CM has been developed from linear productivity model and material balance equation and predicts the total production rate of each producer as a function of the injection rates of all injectors in the system and the bottomhole pressures (BHPs) of all producers. In this paper the CM is modified based on two methods, Pseudo Injectors and BHP methods. Pseudo Injectors method is used for well to well connectivity assessment and BHP method is used for production prediction.
The modified CM was applied for several synthetic field examples and one Iranian oil reservoir. The results of synthetic fields showed that the modified CM can assess the interwell connectivity, reservoir heterogeneity, strength of aquifer, and wellbore productivity in primary production period. In addition, the modified CM can predict production rate and determine suitable areas of future IOR application. The results of modified CM on Iranian field assessed the effect of aquifer in the area and evaluated the degree of heterogeneity of the sands around the producers.
Unlike simulation-based methods, the CM does not require geological and geophysical data to generate the initial model. Developed modified CM can be applied before IOR implementation to assess reservoir continuity and manage future IOR strategies such as well pattern and amount of injected fluid.
A Practical Method for Estimating Stimulated Reservoir Volume in Shale Gas Reservoirs: Coupling Knudsen Diffusion and Surface Diffusion
Authors: Miao Yanan , Lee John , Zhao Chaojie , Lin Wenji , Li Han , Chang Yucui , Zhou Yunjian , Li Xiangfang 
Published: June 2018

Abstract
Estimating stimulated reservoir volume (SRV) in shale gas reservoirs with high accuracy has been of more concern to oil and gas industries. However, current SRV prediction methods are of limited use for characterizing critical flow mechanisms. To make more accurate prediction of SRV in shale gas reservoirs, multiple mechanisms cannot be ignored. In this paper, we develop a novel analytical model to accurately estimate the volume of SRV in shale gas reserviors by incorporating both Knudsen diffusion of bulk gas and surface diffusion of adsorbed gas directly into the model. Depending on flow discrepancies from conventional reservoirs, the modified pseudo-pressure equation to account for these critical transport mechanisms are further constructed. Predicted values of SRV by using this new model are in fair agreement with values from the CMG simulation. Compared with related research, it is the first time that both Knudsen diffusion of bulk gas and surface diffusion of adsorbed gas are taken into consdertion to analyze and estimate the volume of SRV in shale gas reservoirs. A clear workflow for implementation of this method is presented. Compared with the common numerical reservoir simulators, this approach is easier to setup and less data-intensive.
Adapting Fiscal Regimes to Entice Operators to Implement EOR Schemes
Authors: Nunez Fernando , Ramirez Christian Alan , Bashbush Jose Luis , Espinola Oswaldo 
Published: June 2018

Abstract
To optimize profit from Oil and Gas production activities, the Operating companies are often constrained in one side by contract terms with the host governments and on the other side by the nature of the reservoir, its fluids, and the resulting economics associated to its production and development. Enhanced Oil Recovery (EOR) methodologies have shown to provide satisfactory results in increasing the recovery factor. Nonetheless, their applications are normally linked to important capital investments which might turn the economics of the project not favorable, unless enticements are offered to ease the way towards a win-win pre-arrangement.
This paper aims to contrast results from economic evaluations and assessments for the implementation of an EOR methodology in a type field and how to foster cooperation with regulatory bodies to adapt their fiscal conditions to stimulate implementation of EOR techniques. In that way the host country could benefit from higher investment, larger production, increased tax revenue and a better recovery factors while the operating company would be enticed to assemble a quality team to design viable alternatives to maximize recoveries, increase reserves while increasing their profitability.
The methodology proposed considers the calculation of economic and business indicators such as: Net Present Value, Internal Rate of Return, Payout time, Company take and Government take which are obtained considering typical fiscal regimes applicable for Enhanced Oil Recovery techniques as a function of production profiles and EOR methodologies. The analyses are benchmarked versus natural depletion of current development, comparing investment alternatives and technical and economic benefits of possible Enhanced Oil Recovery alternatives and their prudent implementation.
The implementation of EOR techniques for different fields are either incentivized or discouraged as a function of the different terms of typical fiscal regimes for hydrocarbon production. A proper analysis of the alternatives could be used as the basis of negotiations for the fiscal regime configuration to be applied. Provided the regulations are already intelligently designed and properly approved. Various production scenarios are analyzed to ascertain which EOR methodology may be more advantageous from the points of view of operating companies, national oil companies and government take.
A Numerical Model for Pressure Transient Analysis in Fractured Reservoirs with Poorly Connected Fractures
Authors: Chu Hongyang , Liao Xinwei , Chen Zhiming , He Youwei , Zou Jiandong , Zhang Jiali , Zhao Juan , Wei Jiaxin 
Published: June 2018

Abstract
Given that some fractured reservoirs have poorly connected natural fractures, the conventional Warren and Root model (1963) may not applicable. To narrow this gap, we introduce a numerical method to build a dual-porosity model for those reservoirs. To verify this numerical model, we perform a case study with a semianalytical model (SPE-187290-MS) for a discretely fractured reservoir. During the model verification, the pressure response from this numerical model are compared to the semianalytical results for fractured reservoirs with poorly connected fractures. It is found that the difference between the pressure responses obtained by these two models is negligible. Results show that pressure transient behaviors of wells with intersecting fracture exhibit completely different flow regimes with those without intersecting fracture. Bilinear flow, linear flow, transient flow, and pseudo-radial flow may progressively occur for intersecting fracture. A radial flow in matrix occurs for discrete fractures, before the impacts of nature fractures exhibit. Once these impacts are detected, the pressure derivatives show a dual-porosity feature "V-shape", which is virtually quite different from that in Warren and Root's dual-porosity model.
Stability Improvement of CO2 Foam for Enhanced Oil Recovery Applications Using Nanoparticles and Viscoelastic Surfactants
Authors: Farid Ibrahim Ahmed , Nasr-El-Din Hisham 
Published: June 2018

Abstract
CO2-enhanced oil recovery (EOR) was started in 1950. Low sweep efficiency and early breakthrough issues were associated with the CO2-EOR system. Foam-EOR was introduced to improve the sweep efficiency instead of polymers to avoid formation damage caused by polymers. Foam stability reduces in high-salinity environments, high-temperature formations (&gt;212°F), and in contact with crude oil. The present study the using of nanoparticles and viscoelastic surfactants (VES) to improve foam mobility control for EOR application.
This paper study the CO2-foam stability with using alpha olefin sulfonate (AOS) as a foaming agent and the change on the mobility-reduction factor (MRF) for different foam solutions by adding nanoparticles and VES. To achieve this objective, foam-stability for different solutions was measured at 77 and 150°F using high-pressure view chamber (HPVC). Interfacial tension measurements were conducted to investigate the destabilizing effect of crude oil on the different foam systems. Coreflood experiments were conducted using Buff Berea sandstone cores at 150°F, saturated initially with a dead-crude oil. The CO2 foam was injected with 80% quality as tertiary recovery mode. The oil recovery and the pressure drop across the core were measured for the different foam solutions.
Adding silica nanoparticles (0.1 wt%) of size 140 nm and viscoelastic cocamidopropyl betaine surfactant (cocobetaine VES) (0.4 wt%) to the AOS (0.5 wt%) solution improves both foam stability and MRF. In contact with crude oil, unstable oil-in-water emulsion formed inside the foam lamella that decreased foam stability. A weak foam was formed for AOS solution, but the foam stability increased by adding nanoparticles and VES. The interfacial tension measurements revealed positive values for the spreading and the bridging coefficients. Hence, the crude oil spread over the gas-water interface, and lamella films were unstable due to the bridging of oil droplets. The oil recovery from the conventional waterflooding (as a secondary recovery before foam injection) was 48% of the original oil-in-place. From the series coreflood experiments, AOS was not able to enhance the oil recovery. However, more oil was recovered in the presence of nanoparticles (12 %) and VES (18%).
Nanoparticles and VES were able to improve the foam stability for AOS solution. Adding nanoparticles is highly recommended for EOR applications, particularly at high temperatures.
Application of Integrated Dynamic Asset Modeling to Predict and Resolve Production Instabilities in an Offshore Facility, A Case Study, Mexico
Authors: Espinola Oswaldo , Mehranfar Reza , Alvarez Julieta , Villanueva Julio , Vazquez Laura 
Published: June 2018

Abstract
Integrated asset modeling has been used for the last decade with a wide technical application covering different challenges from field development to production optimization. Besides supporting the FEEDS and FEL studies for different purposes. Moreover, the technology has evolved in terms of integration and dynamic or transient simulation has been added as an extra element expanding the possibility to cover different challenges and workflows. The objective of this paper is to show how this dynamic integration (Dynamic integrated asset modeling) was applied to a common problem of several reservoirs that produce water and gas under different dynamic mechanisms (injection, aquifer and gas cap) to understand, from the reservoir perspective, the effects of gas and water conning over the entire production system.
The methodology applied was using a refined sector model solved with numerical simulation and coupled with a transient multiphase flow simulator to see how pressure drop affect the contacts level and shape based on the petrophysical properties and under different production scenarios and generate different graphics to see how this phenomenon behaves. Besides a comparison with all the most analytical correlations used in the literature to identify gas and water conning was performed to see the differences among them and with this dynamic integrated approach. On the other hand, for the production side this coupled model was applied to an offshore facility to see these reservoir effects in the transport system and how they impact in the pipeline and riser due to this abrupt entrance of gas and water changing the flow conditions, flow patterns, pressure drop and creating some instabilities in the separators caused by severe slugging.
The results of this analysis were very useful to understand the total production systems (reservoir-surface) behavior, predict the gas and water breakthrough, establish the critical rates to avoid these problems and see how the results differ in some cases with the common analytical correlations. Specific conditions in the pipeline and riser were established to quantify the slugging problems and evaluate different alternatives to eliminate the instabilities through proposing different scenarios such as gas injection in the riser, top side choking, etc. Application of this integrated approach has been very beneficial in recognizing the source of the problem, offer proper and feasible solutions in development and operational phases. In addition, validating and reducing uncertainty of related literature correlations and give to the production and reservoir engineers a quick and reliable way to know the critical rates that can support the decision-making process.
Optimization under Uncertainty for Reliable Unconventional Play Evaluation. A Case Study in Vaca Muerta Shale Gas Blocks, Argentina
Authors: Mehranfar Reza , Marquez Leonardo , Altman Raphael , kolivand Hassan , Orantes Rodrigo , Espinola Oswaldo 
Published: June 2018

Abstract
The objective of this work is to present a comprehensive workflow to optimize the value of a hydrocarbon asset evaluation project under high degrees of uncertainty. This workflow is applicable to both conventional and unconventional assets. However, because of the considerable level of subsurface uncertainty and high initial costs (mainly due to drilling and hydraulic fracturing operations), unconventional resources are good examples for demonstrating the benefits of the workflow. For the case of an unconventional asset, well spacing and perforation cluster spacing are usually the decision parameters that need to be optimized to increase its value.
The workflow begins with the construction of a representative base case single well gas simulation model for production history matching. Petrophysical, geological, geomechanical, stimulation, completions and production data are interpreted and analyzed together to better understand drivers that could be influencing the production. If this can be repeated with several wells in the block with sufficient production data, the process is enriched as so the level of confidence, as the range of history-matching parameters from these different wells across the block can be captured for sensitivity and uncertainty analysis. Several sets of sensitivities and uncertainty runs are then performed to get a probabilistic production profile in the presence of the most influential parameters. It is important to highlight that usually, the limited number of wells, short production histories, different dynamic behavior in neighboring blocks and the lack of necessary data to help understand well performance all contribute to the high uncertainty in predicting production.
Given the high cost of drilling and hydraulic fracturing and on the other hand the high gas price in Argentina, optimizing well spacing and cluster spacing are critical parameters in the process of unconventional resource evaluation considering the high degree of uncertainty.
Transient and Boundary Dominated Flow Temperature Analysis under Variable Rate Conditions
Authors: Mao Yilin , Zeidouni Mehdi 
Published: June 2018

Abstract
The assumption of constant rate production, which is often invalid for the extended period of production, is one of the fundamental premises for current analytical approaches of temperature transient analysis. This work addressed this issue by introducing novel analytical approaches to model temperature signals under variable rate conditions. The specific methods share underlying theories of superposition principle and production rate normalization from pressure transient analysis. With adapting these methods, cases with complex production history are modelled using analog cases producing with constant rate.
The analytical approach validation is performed by graphically and quantitative estimation of reservoir properties compared with synthetic temperature data. The estimation outputs of these methods include permeability, porosity, drainage area, and damaged zone properties, which are the application combinations from temperature transient analysis and reservoir limits testing. Monitoring well surveillance is extended to variable rate production in this paper. A case documented in the literature is addressed by this temperature analysis for which decent reservoir characterization results are obtained. The temperature analysis proposed in this paper extends the scope of temperature transient analysis to complex production constraints and demonstrates convincing results for practical purposes.
UTILIZAÇÃO DE FORMIGAS (HYMENOPTERA: FORMICIDAE) COMO BIOINDICADORAS EM PLANTIOS DE PINUS NO PARANÁ
Authors: Souza Karen Koch Fernandes de , Sousa Nilton José , Lima Pedro Pacheco dos Santos , Silva Ivan Crespo , Marques Eli Nunes 
Published: June 2018

Os cultivos florestais transformam a paisagem e, como as demais monoculturas, apresentam baixa diversidade. A qualidade dos plantios pode ser investigada por meio da utilização bioindicadores. As formigas são amplamente empregadas como indicadores edáficos porque compreendem um grupo numericamente abundante, possuem ampla diversidade, ocupam diferentes nichos e, comparadas a outros seres vivos, são fáceis de amostrar, além de responderem as pressões ambientais. Esta pesquisa procurou realizar levantamento qualitativo e quantitativo das espécies de formigas de solo presentes em quatro ambientes (remanescente de Floresta Ombrófila Mista e três idades de plantios de Pinus sp.). As coletas ocorreram em quatro etapas distribuídas ao longo de um ano. Em cada unidade amostral foi instalado um transecto de armadilha do tipo pitfall (adaptadas para uso com iscas de sardinha em óleo comestível) contendo cinco armadilhas com 10 m de distância. No total, foram coletados 3374 indivíduos pertencentes à Família Formicidae distribuídos em 23 espécies. A análise qualitativa mostrou que o gênero Pheidole teve o maior registro de indivíduos. O gênero Solenopsis foi o mais freqüente no plantio de Pinus taeda aos oito anos de idade, revelando que o gênero pode estar associado à ambientes perturbados enquanto que o gênero Pachycondyla sp. foi observado com maior freqüência em ambiente com melhor estado de conservação.
Earthquake Damage Predicting System of Songyuan Based on GIS
Authors: Zhenjiang Su , Meng Huang , Shaohui Xie , Dian Zhang , Zhe Wang 
Published: June 2018

Abstract
With the rapid development of cities, the research on urban seismic damage prediction should have a breakthrough based on the modern technology. The paper takes Songyuan of Jilin Province as the research object, and creates a spatial database by field data and Baidu maps. We simulate the earthquake by using the seismic intensity algorithm of the point source and the line source, use the spatial analysis method of PHP+GIS to simulate the influence at different earthquake levels on the urban buildings in Songyuan. At the same time, PHP, HTML and dynamic cutting technique were used to evaluate the disaster in 10 minutes after the earthquake. This system will provide technical support for the prevention of earthquake damage in Songyuan.
Two-point boundary correlation functions of dense loop models
Authors: Morin-Duchesne Alexi , Jacobsen Jesper 
Published: June 2018

We investigate six types of two-point boundary correlation functions
in the dense loop model. These are defined as ratios
Z/Z^0Z/Z0
of partition functions on the m\times nm×n
square lattice, with the boundary condition for
ZZ
depending on two points xx
and yy.
We consider: the insertion of an isolated defect (a) and a pair of
defects (b) in a Dirichlet boundary condition, the transition (c)
between Dirichlet and Neumann boundary conditions, and the connectivity
of clusters (d), loops (e) and boundary segments (f) in a Neumann
boundary condition.For the model of critical dense polymers, corresponding to a
vanishing loop weight (\beta = 0β=0),
we find determinant and pfaffian expressions for these correlators. We
extract the conformal weights of the underlying conformal fields and
find \Delta = -\frac18Δ=−18,
00,
-\frac3{32}−332,
\frac3838,
11,
\tfrac \theta \pi (1+ \tfrac{2\theta}\pi)θπ(1+2θπ),
where \thetaθ
encodes the weight of one class of loops for the correlator of type f.
These results are obtained by analysing the asymptotics of the exact
expressions, and by using the Cardy-Peschel formula in the case where
xx
and yy
are set to the corners. For type b, we find a
\ln|x-y|ln|x−y|
dependence from the asymptotics, and a \ln (\ln n)ln(lnn)
term in the corner free energy. This is consistent with the
interpretation of the boundary condition of type b as the insertion of a
logarithmic field belonging to a rank two Jordan cell.For the other values of \beta = 2 \cos \lambdaβ=2cosλ,
we use the hypothesis of conformal invariance to predict the conformal
weights and find \Delta = \Delta_{1,2}Δ=Δ1,2,
\Delta_{1,3}Δ1,3,
\Delta_{0,\frac12}Δ0,12,
\Delta_{1,0}Δ1,0,
\Delta_{1,-1}Δ1,−1
and \Delta_{\frac{2\theta}\lambda+1,\frac{2\theta}\lambda+1}Δ2θλ+1,2θλ+1,
extending the results of critical dense polymers. With the results for
type f, we reproduce a Coulomb gas prediction for the valence bond
entanglement entropy of Jacobsen and Saleur.