bluuebunny/crossref_metadata_2025 huggingface dataset:
Desenvolvimento profissional docente na educação a distância: relatos de uma pesquisa participante
Authors: Silva Ketiuce Ferreira , Prata-Linhares Martha Maria
Published: March 2017

Este artigo apresenta resultados de uma pesquisa que teve como objetivo compreender o contexto que permeia o desenvolvimento profissional de professores e tutores de um curso de Pedagogia, em uma universidade pública, oferecido na modalidade a distância. O problema motivador da investigação foi buscar responder como tem ocorrido o desenvolvimento profissional docente na Educação a Distância (EaD) e o que fazer para melhorar esse processo. Com uma abordagem qualitativa, pesquisa participante e bibliográfica, identificou-se que,  embora as políticas públicas relativas ao contexto do Sistema Universidade Aberta do Brasil (UAB) demonstrem fragilidades que desfavorecem  o desenvolvimento profissional da docência universitária na EaD, das análises dos dados surgem caminhos para minimizar as dificuldades enfrentadas nesse processo como um maior comprometimento institucional com a EAD e reforço do trabalho  coletivo entre professores e tutores a distância.
EVALUATION OF EFFECTIVENESS IN A NOVEL WOUND HEALING OINTMENT-CROCODILE OIL BURN OINTMENT
Authors: Li Hua-Liang , Deng Yi-Tao , Zhang Zi-Ran , Fu Qi-Rui , Zheng Ya-Hui , Cao Xing-Mei , Nie Jing , Fu Li-Wen , Chen Li-Ping , Xiong You-Xiong , Shen Dong-Yan , Chen Qing-Xi
Published: March 2017

Background: Crocodile oil and its products are used as ointments for burns and scalds in traditional medicines. A new

ointment formulation - crocodile oil burn ointment (COBO) was developed to provide more efficient wound healing

activity. The purpose of the study was to evaluate the burn healing efficacy of this new formulation by employing deep

second-degree burns in a Wistar rat model. The analgesic and anti-inflammatory activities of COBO were also studied

to provide some evidences for its further use.

Materials and methods: The wound healing potential of this formulation was evaluated by employing a deep

second-degree burn rat model and the efficiency was comparatively assessed against a reference ointment – (1% wt ⁄ wt)

silver sulfadiazine (SSD). After 28 days, the animals were euthanized and the wounds were removed for transversal

and longitudinal histological studies. Acetic acid-induced writhing in mice was used to evaluate the analgesic activity

and its anti-inflammatory activity was observed in xylene -induced edema in mice.

Results: COBO enhanced the burn wound healing (20.5±1.3 d) as indicated by significant decrease in wound closure

time compared with the burn control (25.0±2.16 d) (P
Effect of Co-Curricular Activities on Academic Achievement of Students
Authors: Singh Ananya
Published: March 2017

Development of child’s body and mind demand proper nurturing of its physical and intellectual qualities as few of the major determinants of his personality. Therefore, modern approaches of education emphasize on all round development of the child. The process of education is not something static or one time measure rather, continuous and life long endeavor that can be divided in two parts; curricular activities and co-curricular activities. . Co-curricular activities, as the name implies, are those, not directly related with the prescribed curriculum and include; sports, athletics, scouting, cubing, various hobbies, excursions literary societies, dramatics, debates etc. to bring social and physical adjustments in the child.

The study concluded that in wholesome the overall effect of co-curricular activities on the student’s academic performance and personality development is positive. And it compliments the academic activities in attainment of education’s main goal of bringing change in student’s behavior.
Managing Risk Around Offshore Installations Using Autonomous Marine Vehicles While Conducting Exploration Activities
Authors: Pai Sudhir
Published: March 2017

The use of autonomous marine vehicles (AMVs) to do work in marine environments is a new and novel technology approach that reduces the presence of humans and improves safety withour compromising quality of service delivery. Over the last four years, this technology has grown and matured from a level of skepticism to full maturity. One particular AMV glider harnesses kinetic energy from wave action to produce forward propulsion in an environmentally friendly manner. This glider is a hybrid sea-surface and underwater vehicle that has taken the concept of autonomy beyond that of the autonomous underwater vehicle (AUV). This wave-powered sensor platform enables collection and transmission of data gathered at sea on missions lasting up to a year. It is capable of crossing thousands of kilometers of ocean to gather oceanographic data, as well as maintain a stationary position while taking meteorological readings, or it can circle a rig at a preset distance to provide early warning of security or environmental threats. Once deployed, the glider uses no crew, requires no fuel, and produces no emissions, thus eliminating both risks to personnel and impact on the environment.

During a marine seismic survey, the worst possible nightmare is to have any of the seismic survey vessel assets, in particular the streamer spread, collide with the client's installations. This type of collision can occur due to metocean changes and feathering, unpredicted changes in the profile of currents, and the onset of cyclones and hurricanes. Typically, the knowledge of currents around platforms during seismic close pass acquisition (CPA) is provided by acoustic Doppler current profilers (ACDPs) that are bottom mounted on vessels that hold station just outside the 500-m exclusion zone, thus providing real-time currents information to help the seismic fleet navigate. This conventional method is an expensive use of the vessels held on station. Such vessels cost USD10 to 20 thousand per day, and typically these are chase vessels that have been pulled away from their primary duty, which is to chase away unwanted visitors in the area. The AMV provides an alternative; it replaces the vessel and performs the same work more efficiently at a much lower cost. At the same time, the AMV glider lowers HSE risk and reduces the environmental impact.

To date, 35 missions have been completed using this technology, which has resulted in an operational savings of 2 to 3 days per month on average through better management of the CPA and line changes. Slowly, operators are accepting this technology as a viable replacement for vessel-mounted ADCPs.
Mitigating Downhole Vibrations in Bottom Hole Assemblies Using Finite Element Analysis
Authors: Marquez Antonio , Omojuwa Emmanuel , Teodoriu Catalin
Published: March 2017

Mitigating downhole vibrations is paramount to safe and cost-effective drilling. Excessive vibrations in bottom hole assemblies (BHA) generated from rock-bit interactions can be quantified and hence minimized using finite element dynamic analysis as a tool. Hence, improving rate of penetrations (ROP), minimize BHA failures, high cost savings and ultimately eliminate drilling accidents. Extensive research has been done in order to better understand the three main modes that drive these vibrations to undesired magnitudes. These modes are: axial, lateral and torsional vibrations. Axial vibrations are better known as ‘bit-bouncing’, lateral as ‘bit whirling’ and torsional vibration are known as ‘stick-slip’ which is the most common of these three. Previous research has focused on these modes individually and coupling of two of these, but no study using Finite Element Analysis (FEA) has been done considering these three in the same model.

The modern finite element analysis tool utilized in this study provides an opportunity to couple axial, lateral and torsional vibrations for planning and optimization of bottom hole assemblies. This is possible due to the newest developments in computing power and better discretization algorithms. A superimposition of all three vibration modes allows the user to physically see where and when the composite resonance will be generated.

In this paper, three vibration modes will be coupled using (FEA) in an attempt to mitigate vibrations affecting the drillstring and BHA by optimizing the amount and positioning of stabilizers. This analysis is focused on the lower portion of the entire drillstring where the vibrations are generated. This holistic approach is beneficial in design safer well plans and bottom hole assemblies
Getting Ahead of the Curve : Front End Loading HSSE Management Planning in Major Capital Projects
Authors: Wharton Andrew
Published: March 2017

Recent data shows confirmed underperformance in HSSE outcomes in major capital LNG projects, with supply chain HSSE culture being a key risk to large capital project developments. The evidence indicates that starting HSSE related activities and effort in line with construction results in poor HSSE performance characterized by an operating mode of reaction and recovery. However, a proactive approach in working with EPC contractor bidders to ‘front end load’ work on HSSE strategies and plans, and so gaining alignment and contractual agreement up front well before construction work begins, will pay dividends.

This paper discusses why sending the workforce home safely at the end of every day should not be seen as a competitive advantage by a mature organization. Lessons can and should be shared from major capital projects certainly within an organization but also within the LNG industry more widely. Anonymous examples are presented covering the safety outcomes of projects that started robust front end HSSE management systems, practices and initiatives too late (in line with the construction phase start, for example) and of the intervention plans that were then required to recover to acceptable levels of HSSE performance.

Specific lessons learnt from past and current LNG projects will be discussed. This experience and knowledge has helped formulate the HSSE Management strategy and plans for the Lake Charles Liquefaction (LCLNG) Project, known as "Getting Ahead of the Curve". The HSSE front end loading work described in this paper, which is aligned to the LCLNG Project’s overall Performance Management Philosophy, includes but will not be limited to the following: Requirement for strong Project Management Team leadership and an in-depth understanding of the workforce culture on the US Gulf CoastAgreeing training requirements and timing (well up front, before workers arrive at the point of risk)Agreeing minimum HSSE and overall supervision ratiosAgreeing KPIs for HSSE management as part of the overall Project performance management plan, including occupational safety and process safetyEnsuring HSSE plans are project specific and not the typical ‘boiler plate’ corporate materialGetting all requirements agreed with the EPC bidders and embedded into the signed off contract, and so being ‘up front and baked in’Following up with robust EPC bid evaluations, focusing on HSSE management planningGantt chart illustration submission requirement with risk profile changing as the Project moves from construction to introduction of hydrocarbons and onto commissioning and start-up, thus enabling successful HSSE campaigns ahead of key risk activitiesSetting up of the Gulf Coast LNG Safety Leadership Forum with other LNG development proponents

The HSSE management goals of the LCLNG Project will be discussed. It is the intention that actual performance can be reported in subsequent updates as the Project progresses, so that further lessons learnt can be discussed and shared with the SPE HSSE Management community.
The Efficacy of Market-Based Emission Control Systems: A System Dynamics Approach
Authors: Rafieisakhaei Mohammadhussein , Barazandeh Babak
Published: March 2017

Climate change poses a global threat to the sustainable development of human societies. If not controlled, its impacts can threaten a vast range of human life including economic, social welfare, and public health. Most of the human-made part of this phenomenon is caused by the excessive greenhouse gas emissions (GHG), particularly carbon byproducts. Several solutions have been proposed to reduce the carbon emissions. In this paper, we investigate the effectiveness of an Emission Trading System (ETS), with a case study on the European implementation of this approach.

Our approach is based on the system dynamics methodology. First, we perform a literature study on the main sources of carbon emissions, and investigate the key factors involved in the carbon cycle. Then, we extract the casual relations between the derived factors and parameters. On top of the casual model, we build a stock and flow model in which the stock variables are related to their rate variables through a differential equation whose coefficients are time-varying and determined in the model itself. The whole model is reduced to a system of differential equations with variable coefficients, and is solved numerically using methods such as Runge-Kutta. The mathematical relations between the main variables are derived using regression analysis on the available historic data which are used to train the model. For the set of variables where analytic relations cannot be derived or are not suited, look-up tables are utilized.

The main procedure involved in the ETS is providing an Emission Allowance (EA) trading system, by placing a price on the volumes of the emissions. Thereby, financially incentivizing the main entities that emit large amounts of CO2 (or other GHGs in equivalent volumes of CO2) to reduce their emissions. An economic model between the EA Price, Demand and Supply is derived, where the supply is determined according to the regulations (reduced by 1.74% annually), and the demand is proportional to the actual carbon emissions. All main sources of emissions such as the power sector (whose main player is the electricity demand), manufacturing industries and construction, transport sector, aviation, etc., are included in the demand side. For our case study, the data and reports of Eurostat are used and the model is simulated.

A system dynamic model to determine the relations between the emissions production, demand and allowance prices is provided, which implements the method described in the EU ETS. The European data is used to simulate the model. Our simulations show that the EA pricing system can be increasingly effective to control the emissions though the EA prices, by consistently covering more industries (currently only 45% are covered) and reducing the allowance allocations. The possible implications of such a system for the US are investigated.
The Carrot and the Stick of the Electronic Logging Device Mandate
Authors: Seidl John
Published: March 2017

The ELD mandate Final Rule was published in December 2015. While some fleets may not like the FMCSA's Stick, they will ultimately reap many benefits from the use of ELDs – the Carrot. We describe them here, and include best practices for successful ELD implementation.
Leading Indicators For Onshore Drilling HSE Outcomes
Authors: Jablonowski Christopher J.
Published: March 2017

This investigation specifies and estimates regression models to test several hypotheses about the operational and managerial drivers of HSE incidents with emphasis on the identification of potential leading indicator variables. A leading indicator, or precursor, provides a signal of an increase in the likelihood of HSE incidents for future activity. The results of this investigation suggest several viable candidates for precursor variables in onshore drilling, including impending rig moves, changes in supervision, and operator-contractor cumulative experience. The results empower engineering and operations personnel to intervene and initiate mitigation activities. While the investigation was completed for one operator in one geographic area, it is believed the results are generally applicable to other regions, other operators, and very likely to similar industrial sectors.
Analytical Approach to Determine the Degree of Interference Between Multi-Fractured Horizontal Wells
Authors: Molina Oscar , Zeidouni Mehdi
Published: March 2017

Economic development of unconventional reservoirs heavily relies on hydraulic fracturing of horizontal wells in multi-well pads. The application of this technology poses the challenge of determining optimum well spacing. For this reason, well interference analyses have recently gained increased attention in the industry.

The objective of this study is to present an analytical well interference model that is aimed to diagnose interwell communication between multistage-fractured horizontal wells (MFHW) in liquid-rich shales in a dual-well system via fracture overlapping or fracture "hits". The mathematical model is based on the application of the trilinear flow model to two parallel MFHW connected through the inner fracture tips. This situation is represented mathematically using a semi-permeable boundary condition. This condition features a constant α, called the well interference coefficient, which allows history-matching the analytical model with pressure-transient data. Once α is obtained, the degree of well interference is measured using the parameter δw, representative of the fraction of the fractures in comunication. Pressure-transient data is generated numerically for four different dual-MFHW systems with 5, 10, 20 and 50 fractured stages. Fractures half-length also changes for each case study. Petrophysical data from the Lower Eagle Ford shale found in the literature is used to build the reservoir model.

It is shown that the analytical well interference model accurately captures the characteristic pressure-transient behavior of interwell communication due to fracture hits byhistory-matching α with well data for each system. Various degrees of interference are allowed in all system so that a relationship between α and δw is established for each case. Therefore, the degrees of interference δw systematically computed by history-matching α with numerical pressure-transient data from a parent multi-stage fractured system may be extended tomulti-well systemsregardless of thenumber of fractures, so long as both wells have similar characteristics, including reservoir properties and fracture half-length.
Modeling of CO2 Flooding and Huff and Puff Considering Molecular Diffusion and Stress-Dependent Deformation in Tight Oil Reservoir
Authors: Kim Tae Hong , Cho Jinhyung , Lee Kun Sang
Published: March 2017

Recently, the potential of enhanced oil recovery (EOR) with CO2 injection in tight oil reservoir has drawn attention. Most of previous studies for CO2 injection in tight oil reservoir have considered only huff-and-puff process. However, CO2 flooding could show further improvement depending on the fracture-reservoir system. To investigate the effects of CO2 flooding and huff-and-puff processes in tight oil reservoir, numerical models incorporating molecular diffusion and stress-dependent deformation mechanisms were generated. In order to model the realistic tight oil reservoir, core and reservoir models were constructed with data from Bakken shale field. Coand counter-diffusive transport is depicted by Sigmund and Wilke correlation. Stress-dependent deformation in tight reservoir is considered by exponential correlation coupled with linear-elastic model. The developed models were used to investigate major factors affecting CO2 injection process such as molecular diffusion, stress-dependent compaction, and conductivity of fracture system. In the proposed model, about 8% of hydrocarbon was recovered during the primary production. Recoveries with CO2 flooding and huff-and-puff following primary production are increased to 18 and 15%, respectively. The main factor which facilitates CO2 flooding is the fracture conductivity of unstimulated zone. Because the middle Bakken formation shows relatively higher permeability and fracture conductivity than other ultra-tight reservoirs, the CO2 displaces the oil between wells with flooding. In case of the reservoir with lower fracture conductivity, on the ther hand, huff-and-puff process is better than flooding process for EOR. In addition, CO2 flooding process showed higher CO2 storage than huff-and-puff process. CO2 flooding method stores 1.7 times higher CO2 than huff-and-puff method. About 91% of injected CO2 is stored for CO2 flooding and about 54% of injected CO2 is stored for huff-and-puff. Therefore, the need to develop CO2 flooding techniques is evident in order to improve not only the oil recovery but the CO2 storage. The investigation of CO2 flooding and huff-and-puff with comprehensive numerical model suggests better understanding and design of CO2 injection in order to improve the efficiency of CO2 EOR and storage in tight oil reservoirs.
Design and Execution of an MEOR Huff and Puff Pilot in a Wintershall Field
Authors: Aditama P. , Avbelj E. , Reimann S. , Dopffel N. , Mahler E. , Poulsen M. , Jelinek W. , Alkan H.
Published: March 2017

Wintershall is conducting a technology project for development and field application of MEOR (Microbiologically Enhanced Oil Recovery) in collaboration with BASF. The successful results of the laboratory phase led to a first small confined pilot Huff'n’ Puff (HnP) in a Wintershall mature oil field to prove that the laboratory-developed concept works in the field under reservoir conditions.

A suitable well for the MEOR operation was selected in the studied field based on selection criteria. The selected well is a former producer approximately 900 m deep. After a USIT run it was decided to recomplete it. Prior to MEOR HnP pilot, an injectivity test was performed to allow for re-assessment of the current petrophysical and geological properties around the well. In order to establish the baseline for the pilot evaluation, a comprehensive monitoring program consisting of microbiological, chemical and petrophysical surveys commenced just after the well recompletion.

The surface set-up designed for follow-up MEOR field operations was installed in the field. The mixing of the MEOR solution with the injection water was regulated automatically by measuring the injection rate. The injection took four days, followed by an incubation period of five weeks. During the nutrient injection, the injectivity was significantly lower than the one obtained from a previous injectivity test. As a result, the total volume of injected nutrient was lower than initially planned. Nevertheless, the volume was sufficient to achieve the pilot objectives.

The injection was carried out under matrix conditions by keeping the pressure below the fracture pressure. The injected fluid temperature was somewhat lower than planned, but according to downhole measurements, still high enough for microbial growth. It was observed that there was an oxygen ingress into the system through the injection pump, however no detrimental effect was seen on microbial activity. After the shut in period, a comparable volume of the injection fluid was produced back. The tracer concentration in the back produced fluid was used to calibrate the chemical and microbiological effects of MEOR.
Maximizing the Value of Matrix Acidizing Treatments in Carbonate Reservoirs
Authors: Shirley R. M. , Zhu D. , Hill A. D. , Da Motta E. P.
Published: March 2017

It has been well-understood that there exists an optimal condition in matrix acidizing in carbonate formations. When a treatment is not pumped at the optimal conditions, the efficiency of the stimulation suffers. A cost-effective procedure for maximizing matrix acidizing treatment results in carbonates is proposed. This procedure includes a systematic approach to altering the acid schedule, pump schedule and the placement technique. The procedure is particularly important for high temperature or long treatment intervals where achieving optimal injection rate is difficult.

Injecting acid below the optimal injection rate in matrix acidizing of carbonates can negatively impact productivity/injectivity by significantly limiting the final skin reduction. To design a treatment that creates dominant wormholes to improve well performance, the optimal pumping rate must first be determined based on the field conditions which can be scaled up from laboratory core flood data. For cases where the optimal injection rate cannot be achieved because of the limitation of pumping equipment, this paper proposes a counter-intuitive procedure for altering the treatment design. There are means to reduce optimal injection rate for a treatment, such as changing acid concentration, acid type or additives. Reducing acid strength can lead to a slower reaction rate and deeper wormhole penetration. There is however a limit since reducing the acid strength will not only reduce the optimal interstitial velocity but also increase the acid volumes required for breakthrough because of lower acid dissolving power. If the optimal pumping rate cannot be sufficiently reduced, then the placement techniques must be modified to facilitate higher injection rates. Furthermore, the pump schedule must also consider heterogeneity and this may require the use of multiple stages. Using published core flood data along with hypothetical well designs, various acid treatments have been simulated, and the results are presented in terms of skin factor along the well length for each injection strategy. The study demonstrates the application of the proposed procedure.

The results of the study showed that in cases where the pumping rate is less than optimal, simulation results show less than optimal skin factors are predicted. When pumping at low rates, using the highest concentration of acid does not necessarily result in the most efficient wormhole creation and propagation. There is a clear limit to which reducing acid strength can benefit the degree of penetration for a given injection rate. The proposed procedure is a practical means of creating a cost effective acidizing design that not only removes formation damage but creates deep dominant wormholes that minimize the skin factor.
Waterflood Performance Diagnosis and Optimization Using Data-Driven Predictive Analytical Techniques from Capacitance Resistance Models CRM
Authors: Kansao Rami , Yrigoyen Andres , Haris Zameel , Saputelli Luigi
Published: March 2017

Quick evaluation of reservoir performance is one of the main concern in decision making. Time consuming data preparation and processing, and data uncertainty (geological, petrophysical, reservoir engineering) limit the use of numerical simulators in addition to long term response for reservoir management. Effective reservoir management needs quick action regarding injected fluid distribution to improve areal and vertical sweep efficiency during secondary and tertiary recovery processes. Therefore, simpler methods that provide quick results to complement or substitute reservoir simulation are important for reservoir monitoring and management. Capacitance Resistance Model (CRM) is one proven method to address the above challenges. The CRM model is based on the hypothesis that reservoir performance can be inferred from analyzing production and injection data and a simplified analytic model structure. CRM is an input-output and material balance based model that use continuity equation to quantify the connectivity among injector and producer wells, time constant and productivity indices.

In this study, a CRM model was generated to build a forecasting waterflood model by to matching historic production and injection data. After history matching, the model can be used to: (1) effectively forecast oil and water production, (2) evaluate reservoir and production-injection data uncertainties, and (3) optimize injection settings to improve oil recovery factor. CRM methodology is used as a cooperative approach to reservoir simulator generated streamlines.

Different case studies were designed to investigate the robustness of CRM by providing different levels of complexities as compared with numeric simulation results. In the first case, a constant flowing bottomhole pressure and injection rate was considered, and in the second case, changes to flowing bottomhole pressure, injection rate and productivity index per each time step were considered. The CRM was able to replicate the synthetic historic data generated using numerical simulator within a satisfactory error, i.e. less than 7% in the worst case. The CRM injector producer allocation factors were also in line to those computed using streamlines. In both cases, the CRM model showed a higher allocation factor for the injector producer pairs which had better connectivity allowing the evaluation of waterflood performance by pattern while identifying the poor sweep efficiency areas. In a later optimization exercise, a dry oil production objective function was maximized subject to the constraints in the injection system. Thus, strategies derived from CRM model increased production in the range of 12% with associated water cut reduction just by reallocating injection rates.
Increasing Drilling Operational Margins of an Onshore Mature Field in Pakistan by Including a Dynamic Drilling Modeling Approach
Authors: Vielma W. E. , Quijada R. , Feltracco D. , Mittiga V. , Mosti I. , Nergaard K.
Published: March 2017

Access to new reserves and subsequent production is becoming a challenging scenario for oil and gas companies all over the world. In this particular context, a major operator planned an onshore well in Pakistan (located 350km north of Karachi) as part of a revamped drilling campaign in this mature field. However, in previously drilled wells in the vicinity several drilling issues were encountered including, but not limited to, a challenging drilling window with kicks and losses. These are mainly due to formation structural conditions that require very strick control of the equivalent circulating density (ECD) and the equivalent static density (ESD) for new wells drilled in the area.

If successful operationally and if reserves prove economically exploitable, this well will be used as potential reference for future infill drilling in this reservoir. To overcome the issues and ensure the greatest potential to successfully drill this well, it was decided to use managed pressure drilling (MPD) equipment for the last two challenging well sections.

Because of this, a full dynamic drilling modelling solution was selected to support the planning phase and subsequently, the decision process during the operations. The dynamic models applied include consideration of temperature, pressure, mud compressibility and rheology as well as gel breaking effects in a transient simulation. For well control considerations a two-phase model considers both influx of the reservoir fluid and modelling of the fluid properties by equation of state as well as distribution and migration of the influx in a drilling kick scenario.

As direct result of this study, it was decided to revise and slightly adjust the optimized drilling fluid weight to better manage the ECD/ESD, thereby avoiding compromising the integrity of the well during the operations. Some of the specific parameters were re-defined based on the modelling results, providing enhanced best practices for the MPD utilization.

The implemented approach required the drilling practices to be tailored for this particular well and opened the opportunity to implement the lessons learned into the company well design process and drilling practices. For this, a multi-domain collaboration is key to minimize the uncertainty associated with the behavior of the drilling dynamics with respect to the drilling window and the overall operational system. In addition it requires the inclusion of dynamic modelling to provide a more realistic planning approach makes it possible to consider different drilling opportunities in mature fields with challenging profiles.

This paper will describe the analysis done using this dynamic drilling modelling approach, with focus on the primary and secondary well control.
Assessing the Value of Information According to Attitudes Towards Downside Risk and Upside Potential
Authors: Santos Susana M. , Schiozer Denis J.
Published: March 2017

The Value of Information (VoI) analysis typically assesses information opportunities to manage uncertainty. The VoI is traditionally estimated using the expected monetary value (EMV), which overlooks the decision maker's (DM) attitude towards upsides and downsides. In this study, we assess the VoI for DMs with different attitudes, under different levels of information reliability. We define attitude to be as: neutrality to upsides and downsides, aversion to downside risk, and willingness to exploit upside potential. We applied a simple and flexible formula, which incorporates EMV with lower and upper semi-deviations from a benchmark, to quantify downside risk and upside potential. We determined VoI using many uncertain scenarios to maintain interactions between parameters instead of deterministically isolating the uncertainty under analysis. To accelerate analysis and reduce computational costs, we used a set of candidate production strategies optimized for extremely different scenarios. Our case study was the UNISIM-I-D, a benchmark reservoir model with a key structural uncertainty affecting production strategy selection. We used an appraisal well as an information source, and four hypothetical DMs with different attitudes. Our results showed that these DMs value information differently, that one DM may decide to acquire information while another may not, for the same situation. In our case study, information reduced downside risk but did not increase upside potential, meaning that information was more valuable to risk-averse DMs (which was up to 20 times higher), and less valuable to DMs exclusively focused on maximizing upsides.
Numerical Modeling of Mineral Dissolution of Carbonate Rocks During Geological Co2 Sequestration Processes
Authors: Yuan Tao , Ning Yang , Qin Guan
Published: March 2017

Carbonate formation is an ideal candidate for geological CO2 sequestration (GCS) because of its large storage capacity. One of the important issues is the CO2 leakage through highly conductive pathways. During a GCS process, the dissolved CO2 can form a weak acid in brine that can dissolve carbonate rocks by various geochemical reactions. Carbonate rocks are composed of a variety of minerals, including calcite, quartz, clay, etc. Such dissolution process may enhance the existing natural fracture system to eventually form highly conductive pathways for possible CO2 leakage.

In this paper, we have developed a numerical model that couples the Stokes-Brinkman equation instead of the Darcy's Equation and a reactive transport equation, and applied for modeling of the coupled process consisting of fluid flow, solute transport, and chemical reactions. Compared to the Darcy's equation, the Stokes-Brinkman equation is a unified approach for modeling fluid flow in both porous media and free flow regions, which is an ideal candidate for modeling of porosity alteration and fracture enhancement due to mineral dissolution. The nonlinear reactive transport equations are derived for primary species from mass balance equations. In the numerical model, the Stokes-Brinkman equation and the transport reactive equations are solved by a mixed finite element method and the control-volume finite difference method, respectively, in a sequential fashion.

The numerical model is validated using a CO2-saturated brine flooding experiments from the existing publications. Good agreements of effluent concentrations of aqueous species can be found between our simulation results and experimental observations. The numerical simulation study focuses on core-flooding scenarios with different mineral volume fractions and different injection rates in fractured rocks composed of multiple minerals. The preliminary results demonstrated that the mineral volume fractions have significant impact on the porosity alteration and fracture propagation. The calcite dissolution is preferred in acidic fluids over less reactive minerals including quartz and clay, and the rock properties are altered accordingly. The competitive coupling between the flow and chemical reaction rates is another important factor for mineral dissolution in our simulation study. In addition, the simulation results demonstrated that mineral dissolution processes can be altered by controlling the injection rates because the chemical reactions in the GCS processes are reversible.

This work presents a mathematical model allowing us to simulate the dynamic behavior of natural fracture evolution during the GCS processes, and provides some important guidelines for the GCS implementation. Currently, we are trying to apply the simulation technology for solving some real-world problems.
Polynomial-Chaos-Expansion Based Integrated Dynamic Modelling Workflow for Computationally Efficient Reservoir Characterization: A Field Case Study
Authors: Patel Rajan G. , Jain Tarang , Trivedi Japan J.
Published: March 2017

Assisted history matching which integrates production data dynamically in reservoir modelling has been used to reduce uncertainty in reservoir geological properties which leads to credible production forecasting. For largescale heterogeneous heavy oil reservoirs, typically thousands of full physics simulation runs of multimillion grid reservoir models might be required to accurately probe the posterior probability space given the production history of reservoir, therefore not practical. In this paper, a unique approach for computationally efficient dynamic data integration is presented which includes construction of a proxy model that can replace reservoir simulator. Realizations are first parameterized using Karhunen-Loeve (KL) transformation and represented in terms of few uncorrelated random variables. Considering these random variables as input and production parameters as output, a mathematical model based on Polynomial Chaos Expansion (PCE) is constructed using deterministic coefficients and orthogonal polynomials which is further employed in assisted history matching instead of computationally expensive reservoir simulator. History matching of a SAGD field located in northern Alberta is performed using proposed KL-PCE framework and results are compared with the base case that uses commercial reservoir simulator. Ensemble Kalman Filter (EnKF) is used for assisted history matching due to its ability to assimilate data in large-scale nonlinear systems. Effectiveness of proposed idea is evaluated based on the following criteria: (1) Does KL-PCE framework reduce computational cost significantly, and (2) does proposed workflow produce satisfactory history matching results? It is observed that KL-PCE based proxy model provides similar performance as a commercial simulator in terms of ensemble convergence. Also, uncertainty in geological parameters is reduced significantly which is evident from convergence of updated ensemble towards the true value. Furthermore, computing cost of assisted history matching is reduced by almost 95% as training of PCE needs only few full physics simulations. Finally, proposed surrogate-accelerated integrated dynamic modelling can be used in greenfield closed-loop optimization workflows and uncertainty assessment with minimal use of numerical simulator which ultimately maximize the benefit in monetary terms.
Calibration of the Mixing Parameter Model for Viscous Fingering for Varying Water Alternate Gas WAG Ratios and Slug Sizes
Authors: Al-Haboobi Zainab Imad , Christie Mike , Arnold Dan
Published: March 2017

Water alternating gas (WAG) injection is a method of controlling the viscous fingering impact in a miscible flooding processes to improve the volumetric sweep efficiency. The WAG technique is a mix of two conventional techniques: gas injection to improve the microscopic displacement efficiency and water flooding to improve the sweep efficiency. Overall, WAG improves the oil recovery.

Conventional reservoir simulation is too coarse to resolve fingers accurately at field scale. This is because the fingers maybe smaller than field scale grid blocks. Instead, empirical models are used to describe the fingers and to allow simulators to predict realistic recovery.

Effective parameter models such as Todd and Longstaff (1972) are used to model the effects of viscous fingering in field scale. This model is the most commonly used among different reservoir simulators, because it requires the selection of a mixing parameter, ω, whose value includes all of the factors affecting fingering. Additionally, it incorporates a method to calculate the effective viscosity when mixing occurs between oil and gas phases.

Todd and Longstaff (1972) recommended a mixing parameter ω = 2/3 for miscible injection to match the recovery of oil from Blackwell et al.'s (1959) experiments. They recommended ω = 1/3 - 2/3 to account for field scale heterogeneities.

Blunt and Christie (1993) showed that the mixing parameter, ω, needs to be calibrated for WAG injection. They calibrated the value of the mixing parameter, ω, as a function of the fractional flow of injected water. These equations are self-consistent, modified from the effective Todd and Longstaff mobility ratio and have been precisely solved in one dimension to account for fingering in three component systems. But their work was limited to simultaneous injection of water and gas.

In this paper we examine how calibration of ω varies with finite slug size for different WAG ratios using a 1D model. The results show that as the slug size increases, the value of mixing parameter ω, decreases. The value of mixing parameter ω is computed to match the concentration and saturation profiles from 2D simulation.
Updating Reservoir Simulation Models with Well Test Information for Reduction of Uncertainties in Early Field Development
Authors: Toledo S. , Avansi G. D , Schiozer D.
Published: March 2017

The high level of uncertainties during early phases of oilfield projects makes economic decisions challenging. One effective way to reduce uncertainties is gathering reservoir information from dynamic sources, such as well tests and production logging. This data must be incorporated into reservoir characterization integrated studies to generate probabilistic simulation models (scenarios). The objective of this work is to develop a procedure to update reservoir simulation models during reservoir characterization including well test and production logs, aiming better production forecasts.

The proposed methodology consists in generating phi vs. log(k) equations derived from well test and production logging interpretation to update the permeability distribution in probabilistic scenarios without losing geological consistency. We also establish criteria for selecting wells to be tested based on openhole log data. We evaluate the result of the well this data incorporation in a synthetic field based on data from a real reservoir located in Campos Offshore Basin, Brazil. Then, we compared the results with the same reservoir model using classical phi-log(k) equations from laboratory experiments.

Results showed that well test and production logging incorporation can improve the performance of the field measured by the risk curve of the net present value compared to the case without tests. We also showed how the history matching of the pressure derivatives can reduce variability of the prediction of the reservoir future behavior.

The main contribution of this work is to evaluate how new information derived from well test and production logging improves the consistency of geomodels in early development of petroleum fields. Besides this improvement, the results also indicate that this methodology is an efficient way of reducing variability in the production forecast when integrated to other techniques such as history matching. The use of a benchmark case allowed us to show the influence of the quality of the simulation model in the process.
A New Environmentally Friendly Technique to Extend the Limits of Transient Pressure Testing and Sampling Using Pipe Conveyed Open Hole Wireline Formation Testing Tools
Authors: Ayan Cosan , Mishra Vinay , Eriksen Kåre-Otto , Van der Hoek Jeroen , Thorne Tyson
Published: March 2017

Transient well testing is one of the most critical components of reservoir evaluation due to its impact on a project's key economic parameters such as reserves and producibility. A conventional cased hole well test involves casing off the well, installing process equipment, completing the well perforating, flowing the well to surface and flaring the produced fluids. While the data acquired from conventional well tests is very useful; a large number of wells are not tested due to time, cost and regulatory constraints. In such situations with no well test, operators are obliged to take important decisions from a relatively small amount of reservoir information and hence take risks associated with subsurface uncertainties. To help reduce the development risks, a new pipe conveyed testing tool referred as Formation Testing While Tripping (FTWT) was developed. The new testing tool integrates a number of innovations allowing pumping large fluid volumes at higher rates with extended testing time and improved well noise control. This is done by circulating the produced fluids out of the wellbore during pumping out formation fluids. The new hardware can be combined with wireline sampling and downhole fluid analysis modules allowing to achieve overall well testing objectives; including collecting pressure transient data, real time fluid typing and capturing cleaner and larger volume fluid samples, while increasing the radius of investigation for better characterization of any reservoir heterogeneities compared to conventional wireline formation testing techniques.

In this paper, we introduce the new testing technique, which has recently been utilized in the Norwegian sector of the North Sea and offshore Canada. In one well, following the FTWT surveys, Drill Stem Tests (DST) were also conducted for comparison. The field examples and comparison with DST's indicated that the new method can provide valuable reservoir information while also showing its current limitations.
Well, Reservoir and Facility Management – Process, Practice and Impact
Authors: Vliet J. P. , Male P. T.
Published: March 2017

This paper presents an overview of how the Shell Group of Companies has implemented the Well, Reservoir and Facility Management (WRFM) methodology in its Upstream assets. It discusses the different parts of the WRFM Value Loop, and presents case histories and successes from within the Group.

Effective Well, Reservoir and Facility Management requires the integrated contributions of Petroleum Engineering, Production, Facilities and Process Engineering, and Well Services. The detailed WRFM plan defines the type and frequency of the surveillance and data acquisition activities that need to be carried out in order to optimise the production from the asset, and to manage the uncertainties that remain in the development of the asset. WRFM is a structured and integrated approach to data gathering and data management, modeling and interpretation, identification of production enhancement opportunities, and intervention to deliver the opportunities to maximise asset value. This process is represented as the WRFM Continuous Improvement loop, or Value Loop. WRFM targets are set on a yearly basis and progress is measured against the targets. Information and best practices are shared laterally and through the company's global WRFM team.

The various segments of the WRFM loop are presented below in detail, and are illustrated by appropriate case histories. Rigorous application of the WRFM methodology has resulted in considerable improvements in production gains and water injection performance.