bluuebunny/crossref_metadata_2025 huggingface dataset:
China’s Hukou Platform: Windows into the Family
Authors: Siqueira Cassiano Marcella
Published: April 2019

When news media in the UK and US discuss China’s surveillance networks, it is often to imply that the Chinese government is creating a “techno-authoritarian state” to track and monitor its citizens. News outlets, however, are missing a larger point. The specific problem with China’s surveillance apparatus is not that it is technologically “totalizing” and “intrusive,” but that it relies on a newly digitized information platform that connects surveillance subjects to information about their households and family members, allowing the simultaneous identification and monitoring of everyone in each kinship network. Referred to as the Household Register or hukou, this platform is the backbone of China’s “surveillant assemblage” (Haggerty and Ericson 2000). Until the late 1990s when it was digitalized, hukou was an individually separate and distinct surveillance system that contained both general and detailed information about a household and its members. With digitalization, hukou became a platform that integrates different computer systems and databases. CCTV surveillance that involves facial recognition and Internet surveillance practices are connected to, and supported by, information from hukou. In the case of CCTV surveillance, cameras equipped with facial recognition features match the face of surveillance subjects with their ID and trace them back to their families. As for Internet surveillance, the connection between hukou and surveillance subjects happens via telephone number. Access to the Internet and social media platforms such as WeChat, SinaWeibo, and e-mail services requires a telephone number purchased with a government-issued ID card, which is connected to a household register and, therefore, the telephone card owner’s family. Chinese law enforcement’s ability to treat individual Internet users also as “collective units” represents the most distinctive feature of Chinese surveillance, an unlimited source of coercion for the Communist Party to reproduce itself as the ruling party.
POLICY FOR DEVELOPING EXCELLENCE RESEARCH GROUP IN VIETNAM NATIONAL UNIVERSITY, HANOI: REALITY AND SOLUTIONS
Authors: Đào Minh Quân
Published: April 2019

With the goal of objective and systematic evaluation of excellence research group development policy at VNU, in order to help policymakers of VNU can consult and develop scientific and technology development strategy. In this article, we focus on reviewing policies of excellence research group development in VNU, on the basis of analyzing and evaluating three overall groups of policies, including (1) Group of investment policies, human resource development; (2) Policy group to improve the environment and research conditions; (3) Policy group for cooperation and development. For each policy group, we will consider the content, the results achieved, assess the impact of the policy to point out the strengths and limitations to make recommendations for complete solutions
Developing a Coupling Model System of Global Rainfall Data and Open-Source Model for Water Forecast in Poorly Gauged Basins
Authors: Bui Duong Du , Tran Duc Minh , Vu Huong Thi , Bui Nuong Thi
Published: April 2019

Water security is under severe pressures from human interventions and climate change in all over the world and improved water forecast is essential for water management. HYPE is a semi-distributed hydrographic model, running on Windows or Linux operating systems. The code of the model is written by the Fortran programming language and open source as Lesser GNU Public License. HYPE has been becoming a widely used tool in the forecasting of transboundary flows. However, the application of HYPE encounters many difficulties in processing input data and serving the construction, calibration, and validation of the model. This article introduces the development of the V-HYPE tool that helps a couple of global rainfall data and HYPE model for operational use. V-HYPE allows developing a user-friendly interface and setting parameters of the HYPE model as well as evaluating errors and transforming and visually displaying the results of the model. Besides, the V-HYPE has the ability to show related maps (i.e. sub-basins, river network, lake, and dams, etc), set up input data, automatically download global rainfall data, and visually display results on WebGIS. V-HYPE also can generate bulletins supporting for operational water resources warning and forecasting works in Vietnam. The utilities of this tool are demonstrated in the case study of Serepok river basin.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
Comparison among Akaike Information Criterion, Bayesian Information Criterion and Vuong's test in Model Selection: A Case Study of Violated Speed Regulation in Taiwan
Authors: Pho Kim-Hung , Ly Sel , Ly Sal , Lukusa T. Martin
Published: April 2019

When doing research on scientific issues, it is very significant if our research issues are closely connected to real applications. In reality, when analyzing data in practice, there are frequently several models that can appropriate to the survey data. Hence, it is necessary to have a standard criterion to choose the most ecient model. In this article, our primary interest is to compare and discuss about the criteria for selecting a model and its applications. The authors provide approaches and procedures of these methods and apply to the traffic violation data where we look for the most appropriate model among Poisson regression, Zero-inflated Poisson regression and Negative binomial regression to capture between number of violated speed regulations and some factors including distance covered, motorcycle engine and age of respondents by using AIC, BIC and Vuong's test. Based on results on the training, validation and test data set, we find that the criteria AIC and BIC are more consistent and robust performance in model selection than the Vuong's test. In the present paper, the authors also discuss about advantages and disadvantages of these methods and provide some of the suggestions with potential directions in future research. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
Dependency of GPA-ES Algorithm Efficiency on ES Parameters Optimization Strength
Authors: Brandejsky Tomas
Published: April 2019

In herein presented work, the relation between a number of ES iterations and convergence of the whole GPA-ES hybrid algorithm will be studied due to increasing needs to analyze and model large data sets. Evolutionary algorithms are applicable in the areas which are not covered by other artificial intelligence or soft computing techniques like neural networks and deep learning like a search of an algebraic model of data. The difference between time and algorithmic complexity will be also mentioned as well as the problems of multitasking implementation of GPA, where external influences complicate increasing of GPA efficiency via Pseudo Random Number Generator (PRNG) choice optimization. Hybrid evolutionary algorithms like GPA-ES uses GPA for solution structure development and Evolutionary Strategy (ES) for parameters identification are controlled by many parameters. The most significant are sizes of GPA population and sizes of ES populations related to each particular individual in GPA population. There is also a limit of ES algorithm evolutionary cycles. This limit plays two contradictory roles. On one side the bigger number of ES iterations means less chance to omit good solution for wrongly identified parameters, on the opposite side large number of ES iterations significantly increases computational time and thus limits application domain of GPA-ES algorithm. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
DOES PERCEIVED DISCRIMINATION AFFECT JOB SATISFACTION AMONG TEACHERS AND STAFF?
Authors: Indyastuti Devani Laksmi
Published: April 2019

Previous research have not paid much attention on the the mechanism of the relationship between perceived discrimination and the negative outcomes. This research examined the relationship between perception of discrimination and job satisfaction, as well as how basic psychological need satisfaction can play the role in that relationship. This study used teachers and the staff in Purwokerto for the sample. This study used purposive sampling. We choose teachers and staff that have three year experience. This study used individual level of analysis. The result showed that perceived discrimination negatively affects autonomy, relatedness and job satisfaction, but not competence. The relationship between perceived discrimination and job satisfaction was mediated by autonomy. Autonomy positively affects job satisfaction, but not both relatedness and competence. Future research should examine this relationship in other context, for example the bank employees, manufacturer, nurses, etc. Future research also need to examine this relationship that use experiment design to increase internal validity.
PENGARUH PENEMPATAN PRODUK DAN KESADARAN MEREK TERHADAP NIAT MEMBELI
Authors: Juliana Selly , Sihombing Sabrina O.
Published: April 2019

Zipping and zapping is better known as TV channel transfers that viewers can record, pause and repeat TV broadcasts. It can be stated that zipping and zapping can cause ads to be no longer effective and efficient as a means of promotion and communication of products. Therefore, to create good communication, advertising can be used and product placement is one of the advertising choices. Product placement is one of the most advanced advertising industries. Product placement makes the audience's attention indirectly focus on the brand or product that is placed on television shows or films, and companies that use product placement can avoid zipping and electric shocks. Based on the previous explanation, this research was conducted to determine whether product placement had a positive effect on brand awareness and intention to buy Indonesian people. This research was conducted with quantitative research methods through an online questionnaire. This study applied a purposive sampling method and was aimed at respondents who had watched Indonesian Idol 2018. The study consisted of 154 respondents. Data were analyzed using structural equation modeling. The results show that there are two supported hypotheses and one hypothesis that is not supported. This study concludes that there is a positive influence of product placement and brand awareness, there is no positive influence of product placement and purchase intention, and there is a positive influence of brand awareness and purchase intention.
Rethinking Dynamic Knee Valgus and Its Relation to Knee Injury: Normal Movement Requiring Control, Not Avoidance
Authors: Dischiavi Steven L. , Wright Alexis A. , Hegedus Eric J. , Bleakley Chris M.
Published: April 2019

The risk of knee injury in sport may be related to deviations in lower-limb alignment. An example of biomechanical deviation is dynamic knee valgus, considered by many to be one of the most important predictors of serious knee injury; however, the predictive validity of commonly used screening tests for dynamic knee valgus has recently been questioned. In this Viewpoint, the authors argue that assessing the risk of knee injury is complex and endeavor to present pelvic pronation and system tension as a 3-D construct to consider during physical assessments and exercise design, and to recognize dynamic knee valgus as a normal and necessary response to ground reaction forces. J Orthop Sports Phys Ther 2019;49(4):216–218. doi:10.2519/jospt.2019.0606
Advanced Vertical Interference Test Modeling by Considering Petrophysical and Image Based Rock Typing for a Better Kv Estimation in a Heterogeneous Reservoir-A New Workflow
Authors: Kumar Arvind , Batshas Siddhanta , Nagaraj Guru , Nahar Siddhartha , Singh Suraj , Chatterjee Chandreyi
Published: April 2019

Vertical Interference Tests (VIT) using wireline formation testers are industry standard tests to estimate the vertical permeability of reservoir pay zones. In general, the test interval is considered homogeneous for the interpretation, leading to an inaccurate estimation of vertical permeability (Kv) in complex geological systems like thin laminated beds, channel sands, etc. This paper presents a novel approach of accounting for this heterogeneity through use of petrophysical and borehole image-based rock-typing methods, thus leading to a more realistic characterization of vertical permeability.

Advanced petrophysical logs and images are used to generate rock types through Artificial Neural Network (ANN) and Stratigraphic Modified Lorentz Plot (SMLP) techniques. These rock types are then used as an input into vertical interference test interpretation model, thereby factoring in the reservoir heterogeneity for deriving the vertical permeability. This is followed by a sensitivity analysis to examine the impact of the permeability results in multiple geological systems like channel sands, thin bed lamination, near to fault, pinch outs etc.

Vertical permeability (Kv) is a major input in majority of the advanced reservoir engineering calculations and has a significant impact on the field development plan and IOR/EOR techniques. This unique approach of accounting for rock types in a VIT interpretation model leads to a relatively good estimation of vertical permeability. The rock typing techniques used here, allow the user to define the number of layers and minimum interval thickness, which is extremely useful in highly laminated reservoirs. The sensitivity analysis plays a key role in understanding the utility limitations of both conventional and new approach in complex geological systems. In case of thick homogeneous reservoir, sand units, the conventional approach could be used with fairly accurate results. However, in cases of thin sand-shale units with low net-to-gross ratio, this approach gives a good estimation of layer-wise permeability distribution.

This paper presents a unique blend of petrophysical and dynamic workflows into a novel workflow. The results from the sensitivity study, discussed in the paper, can be used as standard criteria in determining the best suitable technique for interpretation of a vertical interference test. This unique approach allows the user to optimize on the interpretation time and to simultaneously ensure the accuracy of results.
Automated Pressure Transient Analysis: A Cloud-Based Approach
Authors: Guo Yonggui , Zidane Ali , Panchal Yashesh , Abou-Sayed Omar , Abou-Sayed Ahmed
Published: April 2019

Pressure transient analysis provides useful information to evaluate injection induced fracture geometry, permeability damage near wellbore and pressure elevation in injection zone. Manual analysis of pressure data after each injection cycle could be subjective and time-consuming. In this study a cloud-based approach to automatically analyze pressure data will be presented, which is aimed to improve the reliability and efficiency of pressure transient analysis.

There are two fundamental requirements for the automated pressure transient analysis: 1) Pressure data needs to be automatically retrieved from field sites and fed to analyzer; 2) Analyzer can automatically select instantaneous shut-in pressure (ISIP), identify flow regimes, and determine fracture closure point. To meet these requirements and also take the advantages of cloud storage and computing technologies, a web based application has been developed to pull real time injection data from any field sites and push it to a cloud database. Besides analyzing any existing pressure data in the cloud database, a built-in pressure transient analyzer can also detect any real-time pressure data and perform pressure analysis automatically when required data is available.

The automated, cloud-based pressure transient analysis has been applied to multiple injection projects. In general, the analysis results including permeability, fracture half length, skin factor, and fracture closure pressure are comparable to these yielded from manual analysis. The discrepancy is mainly caused by poor data quality. The inconsistent selections of ISIP and different slopes defined for G-function and flow regime analyses also contribute to the divergence. Overall, the automated pressure transient analysis provides consistent results as the exact same criteria are applied to the pressure data, and analysis results are independent on analyzer’s experience and knowledge. In addition, machine learning algorithms are applied to continuously refine the criteria and improve the quality of analysis results.

As data from oil/gas industry increases exponentially over time, automated data transmission, storage, analysis and access are essential to maximize the value of the data and reduce operation cost. The automated pressure transient analysis presented here demonstrates that cloud storage and computing combined with automated analysis tools is an optimal way to overcome big data challenges facing by oil/gas industry.
An Innovative Simulated Experimental System for Evaluating PCP Elastomer's Dynamic Fatigue Properties
Authors: Cao Gang , Huang Youquan , Cong Chuanbo , GE Weitao
Published: April 2019

Elastomer is the core component of progressing cavity pump (PCP) which influences the running life of PCP considerably. Conventional elastomer performance tests only show basic mechanical and physical properties mainly simulate the static mechanic performance of elastomer. Numerical simulation indicates that dynamic performance is much more valuable in evaluating PCP's running life, while elastomer's dynamic test has not common criteria in the industry, especially for dynamic fatigue property test. This paper presents a novel simulated experimental design which could effectively evaluate dynamic fatigue properties of PCP elastomer.

Based on the operating conditions of PCP lifting system, a special experiment system has been designed and tested. It consists of power transmission system, friction pair system, and temperature control system. After implementing a series of contrasted tests, a special structure of elastomer sample and testing process were designed which showed best performance in accelerating dynamic fatigue process of elastomer as well as to simplify simulated test principle.

In order to verify the evaluation result of this fatigue testing system, three candidate elastomer formula (sample A, B, C) were evaluated. Experiments showed that dynamic fatigue properties of sample C were better than A and B. The fatigue properties of sample A was the worst. Statistics indicated that average running life of elastomer A was about 550 days, while running life of Elastomer B was 590 days and Elastomer C was 670 days. The application results had the same principle with experimental results. Experiments indicated that this simulated experimental system could describe the dynamic fatigue performance directly and clearly.

This paper presented a new experimental design which could evaluate the dynamic fatigue properties of PCP elasomer based on simulating PCP's operating conditions in practice. This experimental system has been applied to guide the design of elastomer formula and showed good results. This experimental system and testing process are of great significance in evaluating PCP elastomer's performance and developing high performance PCP elastomer in various operating conditions.
Conformance Control for SAGD Using Oil-in-Water Emulsions in Heterogeneous Oil Sands Reservoirs
Authors: Ni Yidan , Ding Boxin , Yu Long , Dong Mingzhe , Gates Ian D. , Yuan Yanguang
Published: April 2019

Steam-Assisted Gravity Drainage (SAGD) is a widely used technology for heavy oil and bitumen recovery in Alberta, Canada. However, a SAGD conformance problem arises due to the heterogeneity of oil sands reservoirs, such as the presence of high permeability zones and high water saturation zones. In particular, during a geomechanical dilation start-up process that has been developed and applied in SAGD start-up operations, the dilation fluid tends to flow into the high permeability zones, leaving the low per-meability zones un-swept. Therefore, the high permeability zones must be temporarily and selectively blocked off so as to more effectively dilate the low permeability zones along a SAGD well-pair.

Laboratory permeability reduction tests in sandpacks by oil-in-water (O/W) emulsion injection showed that a permeability reduction of up to 99.95% can be achieved. Results of emulsion injection in parallel-sandpack tests demonstrated that a good conformance control can be obtained by a suitable combinations of IFT, emulsion quality, emulsion slug size, and oil phase viscosity of an emulsion system. The reservoir simulation study was conducted to first match the laboratory test results and then to optimize SAGD conformance control operations by emulsion injection in heterogeneous oil sands reservoirs. A field-scale SAGD simulation model was established to show that emulsion injection during the dilation start-up process can build up communication between the injector and producer, resulting in better steam chamber growth and lower cumulative steam-oil-ratio (CSOR).
Laboratory Comparison of Natural Fractures and Induced Fracture Permeability Variations Under Simulated Dynamic Reservoir Conditions
Authors: Santagati Antonio A. , Makrami Adnan H. , Caliboso Edwin T.
Published: April 2019

The objective of this study is to compare the laboratory behavior of natural (Mode II) and induced (Mode I and II) fractures during stress-dependent permeability tests (SDk) to verify under which conditions the hydraulic behavior of induced fractures may be assumed to be representative of that of in-situ natural fractures.

Fracture modes are identified by the way the force that enables the crack to propagate is applied and may be of three different types. Mode I fractures (propagated by a tensile stress normal to the plane of the crack) and Mode II fractures (propagated by a shear stress acting parallel to the plane of the crack and perpendicular to the crack front) are of import in the present study.

To test under which conditions this assumption may hold, cylindrical specimens of different rock types including plugs with an intact matrix and plugs with a natural fracture propagating through their body were selected. When possible, the plugs were grouped in pairs so as to form homogeneous sets characterized by a coherence in specific matrix properties (porosity, density, permeability), with each pair including a plug containing a natural fracture. Induced Mode I and Mode II fractures were then propagated axially through the intact specimens and each plug set was tested for SDk. All of the tests were run under similar triaxial test conditions.
Steam Chamber Description Using Seismic and Production Data
Authors: He Weisheng , Wang Yan , Wang Huifeng , Wang Yongjun , Pan Tingting , Deng Zhiwen
Published: April 2019

A heavy oil field is developed with the Steam Assisted Gravity Drainage (SAGD). Since the start of oil production, the oil production amount of the studied reservoir has been lower than that of the surrounding oil fields. The development of the steam chambers are relatively poor, and the spatial distribution of the steam chambers is not clear. In order to describe the shape of the steam chambers accurately, a novel method of monitoring the steam chambers is proposed by using broadband, high-density seismic data and dynamic production data. Broadband, high-density seismic data are acquired. Firstly, seismic horizons are well interpreted, and multiple seismic attributes are analyzed in combination with well data to understand the seismic response of the steam chambers. Then, several seismic inversion methods are tried to obtain high-resolution impedance, and they are compared with each other to find optimal inversion result for steam chamber prediction. Finally, the shape of the steam chambers are delineated with seismic attributes, inverted impedance, production data, and temperature logs of observation wells. The predicted steam chamber has good agreement with the temperature logs of observation wells. The result shows that the appearance of steam chambers has an obvious impact on seismic signals, and broadband, high-density seismic data make great contributions to the description of the steam chambers. The proposed method reduces the uncertainty in steam chamber prediction with single data source, and is applicable to other oilfields using steam injection.
Anti-Gas Channeling Cementing Technology for Ultra-Deep High Temperature and High Pressure Gas Wells
Authors: Zeng Yijin , Gao Yuan , Zhou Shiming , Tao Qian , Sang Laiyu , Yang Guangguo , Lu Peiqing
Published: April 2019

Many challenges exist in ultra-deep high-temperature and high-pressure gas well cementing, such as, high-temperature, active gas layer, narrow density window, and seal integrity failure of cement sheath, which brings huge difficulties in anti-gas channeling cementing. By selecting the nano-liquid silicon and latex anti-gas channeling agents, and synergistically enhancing the anti-gas channeling performance of cement slurry, the mechanical properties of cement set is improved; by optimizing the compounding and dosage of silicon powder with different particle sizes, the high-temperature stability of cement set is enhanced. Via the selection of inorganic fiber cracking-prevention and plugging system, the crack propagation is inhibited, and the leakage resistance of cement slurry and the impact resistance of cement set are improved. Hence, a high-temperature resistant latex anti-gas channeling cement slurry system was developed. The cement slurry system has the following properties: API water loss of <50 mL at 180 °C, SPN value of <1, cement set compressive strength of 39.3 MPa under 200 °C×21 MPa×60 d, Young's modulus of 6.9 GPa, gas layer permeability of 0.004×10-3 μm2, and its comprehensive mechanical properties are better than that on the 30th day. The cement sheath seal integrity evaluation shows that the 26.7 mm sheath can achieve an effective seal effect under the cyclic loading process (peak pressure is 90 MPa). Combined with the staged gas layer stability prediction, the pressure management cementing technology under unsteady conditions was proposed, which solves the problems of gas channeling and leakage prevention in ultra-deep high-temperature and high-pressure reservoirs with enriched fracture-cavity. The anti-gas channeling cementing technology has been used in the Shunnan and Shunbei plays of Sinopec Northwest Oilfield Company, and it can provide references for the cementing of similar gas wells.
A Semi-Analytical Model for Complex Fracture Geometries with Fracture Hits
Authors: Chen Zhiming , Xie Jianyong , Liao Xinwei , Li Xiaofeng , Zhang Jiali , Li Rongtao , Li Lang
Published: April 2019

In this study, we develop a new model for the complex fracture geometries with fracture hits using an efficient semi-analytical model. The semi-analytical model has the capability to simulate shale well performance by considering complex non-planar hydraulic fractures and fracture hits. By combining nodal analysis and Laplace transforms, the pressure transient solution of the diffusivity equation is obtained. The semi-analytical model is verified against the numerical models. Then, we apply the model to analyze pressure testing data of a parent well and a child well. Results show that the flow regimes of complex fracture geometries with fracture hits include wellbore storage, skin effect, fracture bilinear flow, "fluid feed", pseudo-boundary dominated flow, unconnected fracture (UF) impact, and pseudo radial flow. During the flow regime of UF impact, the pressure derivative curves exist a second "V-shape", as the UF improve the matrix permeability and the pressure depletion will be reduce once the flow reaches the UF. Those flow regimes provide good guidelines for identification of complex fracture networks with fracture hits.
A Fundamental Model for Wormhole Formation Including Multiphase Flow
Authors: Cheng Haoran , Schwalbert Mateus Palharini , Hill A. Daniel , Zhu Ding
Published: April 2019

The industry has been developing numerical models to simulate the wormholing phenomenon in carbonate matrix acidizing, both to save cost and time with experiments and to upscale the laboratory results to the field scale. The Two-Scale Continuum Model is a fundamental model that has been successfully used for this end. Previous studies with this model only simulated single-phase flow: injection of acid into a water saturated rock. However, significantly different behavior is observed experimentally by injecting acid into oil or gas saturated cores. In this work a fundamental multiphase model for wormhole formation is presented using the two-scale continuum approach, allowing the simulation of the wormholing for acid injection into oil or gas bearing rocks, with different saturations.

The two-scale continuum model represents the fluid flow and acid transport in the porous medium in the Darcy scale, but calculates the acid-rock reaction with dissolution of the rock in the pore scale. This model was implemented in transient three-dimensional anisotropic form. Each different phase occupies a volume fraction in each grid block, defined by the porosity and fluids saturations. The fluid flow is calculated by solving the Darcy-Brinkman-Stokes equation, where the relative permeabilities are functions of the saturations. The acid transport and reaction equations are solved, and as the acid injection proceeds and the rock is dissolved, the porosity increases in the grid blocks where dissolution occurs. The pore properties such as permeability, pore radius, and specific surface area are updated as porosity evolves, being upscaled from pore to Darcy scale. The simulation keeps track of the different fluid phases by calculating the saturations using the Implicit Pressure Explicit Saturation (IMPES) method.

The developed model was implemented in an open source Computational Fluid Dynamics package and validated against experimental data. For the validation, the adjustable parameters in the model were calibrated so that the simulation results represent the different dissolution patterns and correctly reproduce the acid efficiency curves obtained experimentally. The same calibrated model was used to simulate the core flooding experiments with water and oil saturated cores. The dissolution patterns (face dissolution, conical wormhole, dominant wormhole, etc) and acid efficiency curves predicted by the new model match the experimental data. Other simulations presented include the shift in the acid efficiency curves observed for different oil viscosities, residual oil saturations, and different water saturations.

To the authors’ knowledge, this is the first two-scale continuum model to simulate wormhole propagation including multiphase flow. With adequate history match, it was shown to accurately predict the acidizing results for different fluid saturations, as observed in experiments.
KPI Based Standardizing Static Geomodeling Practices for QA and QC of Models
Authors: Dhote Prashant , Al-Adwani Talal , Al-Bahar Mohammad , Al-Otaibi Ahmad , Chakraborty Subrata , Stojic Slobodan
Published: April 2019

Subsurface petroleum industry is burdened with uncertainties in every aspect from exploration to production due to limitations of accessibility to reservoir and technology. The most important tools used to understand, quantify and mitigate the uncertainties are geostatistical static modeling and numerical dynamic simulation geomodels. Geomodels are widely used in the industry for characterizing the reservoir and planning favorable development strategy. It is vital instrument for maximizing asset value and optimize project economics.

Static geomodels are foundation for all the advanced numerical and analytical solutions to solve the intricacies of reservoir performance. At the same time, it is where all the static and dynamic geological and engineering observations get integrated to develop common understanding of the reservoir for future studies. Understanding of the above observations and imaging of reservoir framework by individual is the basis for building static geomodels. Hence, at time, the process is highly subjective and proper QC'ing of the models to achieve the general and specific modeling objectives becomes imperative. Simple Questionaries’ based QC'ing and ranking methodologies are also controlled by subjectivity and individual preferences.

In the present endeavor, quantitative ‘Key Performance Indicators (KPIs)’ based standard static geomodeling practices and QC'ing methodologies at corporate level are developed in specially designed "Process Implementation Project (PIP) – Hydrocarbon resource and Uncertainty Management"’ under the aegis of ‘Kuwait Oil Company (KOC) - Reservoir Management Best Practices Steering Committee'.

The main objectives are to establish a practical modeling process, workflows and criteria to standardize modeling processes. A structured self-guidling modeling document has been developed with self-assemment guidelines and questionary. Finally, for each individual process a set of KPIs are specified as minimum standard to meet to obtain the approval of static model.

The present efforts are important for any geologists, geomodelers and reservoir engineers dealing with geostatistical and numerical reservoir modeling and will provide the KPI's based general practices for quality assurance (QA) and QC'ing of the models.
Benchmarking of State-of-the-Art Assisted History Matching Methods Under Reservoir Uncertainty on a Complex Water-Flooding Process
Authors: Maucec Marko , Saffar Ali , Turki Ali , Fahmy Ismail
Published: April 2019

In this paper we present the framework and results of a benchmarking study to validate performance of conceptually different methods for computer-assisted history matching (AHM) under reservoir uncertainty on an example of complex waterflooding process.

Traditionally reservoir models were manually reconciled with production data, relying mostly on workflows based on engineering judgment and established best practices. The main disadvantage of the manual HM process is that the reservoir simulation disengages from the geological model and fails to quantify reservoir uncertainty. The oil and gas industry has advanced in developing methods for AHM that enable producing geologically-consistent reservoir simulation models with robust uncertainty quantification and high predictive value. In our study we build distinctive, computationally-intensive AHM workflows covering global multi-objective stochastic optimization and streamline sensitivity-based inversion to perform dynamic real-field model update and history matching.

We use the model of faulted reservoir under a waterflooding improved oil recovery regime. A comprehensive geo-modeling workflow incorporates facies, petrophysical properties, and saturation height function with uncertainty quantification performed on rock types, porosity, permeability, Kv/Kh, water saturation and fault transmissibility. During dynamic model update, the uncertainty workflows were executed as data assimilation on the sufficiently diverse prior ensemble of geomodel realizations, and as a Closed (Big) Loop process, where geomodel realizations are parameterized and updated simultaneously (on-the-fly) using global optimization. The misfit function, subject to minimization, incorporates oil and water rates and static wellhead pressure.

The study concludes that different AHM techniques demonstrate different convergence performance. The overall success dramatically depends on the uncertainty quantification of the initial geomodel. Practical reservoir simulation times were achieved through utilization of a Massive Parallel Processing deployed on an HPC cluster. However, most importantly we demonstrate that, by deploying advanced AHM workflows, the updates of geologically and structurally complex models, with tens of millions grid-cells and large number of matched wells can render geology well-conditioned realizations, without necessity of introducing non-geological features in order to achieve a satisfactory match. Thus, the validated practices add a tangible business value to the process of integrated reservoir modeling by delivering a robust simulation model with high predictive value for future field development planning.
Experimental Investigation on Wellbore Strengthening Mechanism and Tight Fracture Plugging Drilling Fluid Based on Granular Matter Mechanics
Authors: Liu Junyi , Guo Baoyu , Qiu Zhengsong
Published: April 2019

With the promotion of oil and gas development around the world, the exploration scope has been gradually extended to complicated geological reservoirs, such as deep or ultra-deep, unconventional, deep-water reservoirs, and lost circulation and wellbore instability have been becoming the most serious problems, which puts forward higher requirements on the drilling fluid technology. In order to solve these technical problems, the wellbore strengthening mechanism, tight fracture plugging methods and simulation experimental method for drilling fluids were studied respectively in this paper.

Firstly, the wellbore strengthening mechanism of the stress cage method that improves wellbore pressure containment was firstly investigated based on ABAQUS finite element modeling analysis. It was found that wellbore pressure containment could be improved by enhancing plugging performance of drilling fluids to plug and prop natural or induced fractures to eliminate fracture propagation and increase hoop stress. The key performance of loss prevention materials has been proved to play a prominent role to achieve wellbore strengthening effect and strengthen the wellbore. According to the basic principle of "force-chain" in granular matter mechanics, the key fine technical indices were proposed to evaluate the particle strength, particle resiliency and surface friction of loss prevention materials. Meanwhile, the corresponding physical model of tight fracture plugging zones was established to reveal the tight fracture plugging mechanism at micro scale and the optimization method of tight plugging drilling fluids was also put forward, and it was concluded that using reasonable particle type, particle size distribution and concentration control, rigid particles, resilient particles and fibers were synergized to plug fractures, so as to form tight pressure containment plugging zones with a strong force chain network and greatly improve the wellbore pressure containment.

The novel experimental apparatus for evaluation and dynamic simulation on the plugging characteristics of drilling fluids was developed, which could simulate the loss and plugging process of fractures with different openings under different formation pressures and temperatures. Using this novel experimental apparatus, the strengthened tight plugging formulas were also optimized for drilling fluid at the wedge fractures with different widths, which exhibited tight plugging characteristic self-adapting to different openings with pressure resistance up to 8MPa, thus improving loss-prevention ability of drilling fluid and significantly enhancing wellbore pressure containment of subsurface formation.
A New Reservoir Prediction Method Based on Geological Seismic Conditioning for Complex Barrier Island and Its Application at H Oil Field
Authors: Chen Xin , Zhang Suhong , Ou Jin , Ye Yufeng , Xu Lei , Ma Yingze , Wei Xiaodong , Yang Ke , Chen Gang , Zhou Guofeng , Xia Yaliang , Yan Xiaohuan , Zhang Zeren , Liu Jingluan , Zhou Xiaoming
Published: April 2019

In order to improve the accuracy of reservoir prediction results, the conventional method usually include seismic inversion, and seismic attribute analysis. Due to the limitation of the vertical resolution of seismic data, it is hard to identify the thin reservoir by seismic attributes directly. In order to improve the prediction accuracy of reservoir, this paper show a new reservoir characterization technique based on geological seismic conditioning. The new method mainly includes five steps. The first step is sedimentary facies classification based on the geological seismic analysis, such as core data, thin section analysis, FMI logging, NMR logging and conventional logging. The second step is modern sedimentary model optimization and forward modelling. In order to establish a reasonable sedimentary facies model, a similar barrier island modern sedimentary model was chosen. To understand the geological significance of seismic data, two different dominant frequency were designed for forward modelling based on the sedimentary facies model and petrophysical analysis. The third step is seismic conditioning under the guide of sedimentary facies model forward modelling. The next step is seismic constraint stochastic inversion, and the last step is reservoir characterization and new well confirm. The application of this method in A oilfield shows that the techniques not only improved the identification ability of the reprocessing seismic data, but also improved the prediction accuracy of the reservoir characterization results. This new reservoir characterization technique can integrated multidisplinary information, such as modern sedimentary model, well data and seismic data, to establish a reasonable sedimentary model, to enhance the resolution of seismic data by conditioning, and get an reasonable reservoir characterization results based on the seismic inversion.
Integrated Multi-Disciplinary Analysis on Flow Characteristics in Transition Zones: Case Studies in Offshore Malaysia
Authors: Marzuki Izral Izarruddin Bin , Masoudi Rahim , Murugesu Thanapala Singam , Ranjan Rakesh , Johare Dzulfadly
Published: April 2019

Transition zone (TZ) refers to a certain height above the Free Water Level (FWL) where both hydrocarbon and water could potentially flow together. The two phases flow is not the definite situation based on the actual fields’ performance observation and it is an ongoing common misunderstanding with broad level of subjectivities for years. Lack of relevant experimental data and the insufficient physical understanding of the characteristics of the transition zone makes the modeling of both 3D static and dynamics to be challenging, subjective and finally uncertain when it comes to predictive capability.

The recent studies by the team and this paper aim to illustrate that in the transition zone due to the relatively lower capillary force, oil has usually occupied the bigger pores compared to the intervals above the transition zone and hence the oil is more prone to move. Also, under enough drawdown and differential pressure level where it could be sensed by aquifer, water could also be fed by aquifer through the established water film by capillary. However, the water saturation in the transition zone will not be reduced through production compared to the initial water saturation. Hence, the relative permeability curves should be cautiously developed to represent the flow condition in the transition zone.

Three oil rim developments in Malaysia with established transition zone and enough production & relevant surveillance history have been selected for this study. There is evidence from actual production data on dry oil recovery from transition zone between one to two years after those wells were put into production. Depending on the standoff of bottom perforated interval with oil water contact (OWC), water production onset may vary with time. Some of the fields have been placed with several horizontal wells in tapping the oil within transition zone to maximize recovery.

This paper will discuss an integrated multi-disciplinary views on understanding the flow characteristics and dry oil production from transition zone. Understanding the capillary pressure, depletion and drawdown strategy together with well completion design as well as location in respect with height above Free Water Level (FWL) is crucial in successful monetization of the transition zone.
Oil Detection Based on Layer Buried-Depth Corrected Elastic Inversion in Deepwater of the Pearl River Basin
Authors: Liu Xumin , Chen Zhaoming , Liu Hao , Zhang Wenzhu
Published: April 2019

Because of the high drilling expense and fewer wells having been drilled in Deepwater of the Pearl River Basin, the complexity and difficulty of oil and gas exploration in this area always restrict our development procedure. In order to overcome these problems in oil and gas exploration, this paper will propose a comprehensive and feasiable approach, which makes full use of both well logging data and seisimic data and combine techniques of rock physical modelling and seismic pre-stack inversion. Such a well-orgnised technical system searching is conducive to reduce exploration risk and promote success rate of hydrocarbon discovery. To illustrate the overall implementation procedure, a case study is applied and composed by 3 corresponding aspects: (1) based on well elastic parameters analysis, LamdaRho (Lame coefficient* Density) is inferred as the sensitive parameter of reservoir and hydrocarbon; (2) With the help of rock physic modeling and fluid substitution, we confirm that LMR is the most sensitive hydrocarbon parameter, and the LMR response varies from substituted fluid type;(3) Considering the difference of layer's buried-depth between evaluated structure and drilled wells, a buried depth correction is applied to eliminate its caused uncertainty of hydrocarbon predition.