bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constant GOR as an Infinite Acting Effect in Reservoirs Producing Below (Dew/Bubble) Saturation Pressure
Authors: Zhang Miao , Ayala Luis F. 
Published: September 2015

Abstract
In recent years, constant producing gas-oil-ratio (GOR) trends have been repeatedly observed in many unconventional oil and gas reservoirs. This effect can last many years, even after the depleting system is believed to have crossed its saturation pressure. In this study, we corroborate that constant GOR could indeed be expected in depleting reservoir systems exhibiting early-transient infinite-acting flow under constant bottomhole pressure (BHP) production constraint for both linear and radial flow geometries. This effect had been shown to be present in infinite-acting linear systems by previous authors; but this study shows how this GOR trend and value can be fully predicted prior to availability of production data. Focusing on liquid-rich gas systems, we start with the applicable multiphase governing flow equations and provide semi analytical and rigorous solutions. Similarity theory is applied to transform the resulting system of equations and achieve the multiphase solution. The results show that a constant GOR effect could be maintained as long as the flow regime remains infinite-acting, which is a typical condition to be found in unconventional systems. Also, it is found that, in both linear and radial multiphase systems, this constant or stabilized GOR is shown to be present regardless of condensate phase mobility at sandface conditions.
Logging Services: Towards the 3D Measurement of Formation Properties in High-Resolution with a Continuous Depth of Investigation
Authors: Walker Kristoffer , Granville John , Kainer Gary , Cheng Arthur 
Published: September 2015

Abstract
The Xaminer Sonic is a new wireline acoustic logging tool that represents the culmination of 4 years of computer modeling, engineering, lab testing, field surveys, and data analysis from fast and slow formations. Spanning a total of 52 ft, the tool includes a 6-ft-long array of 13 rings of eight azimuthally separated receivers located every 6 in. along the axis. There are a total of 104 individual receivers, each a piezoelectric hydrophone with a precisely matched response from 300 to 25,000 Hz. Four monopole piezoelectric sources and two orthogonal dipole shaker sources are located at different offsets to and different sides of the receiver array, permitting an advanced, multi-scale, 3-D interrogation of the formation's elastic properties with a continuous depth of investigation. These sources transmit a modally pure, full spectrum of acoustic energy into the formation using minimum phase and chirp drive pulses. Substantial modeling and engineering efforts have produced a tool structure design that mitigates the effects of the tool and enables broadband measurement of formation compressional, Stoneley, and flexural wave dispersion. By virtue of this unique tool design, load-bearing axial stresses are automatically transferred from the weaker inner tube to the stronger outer structure when hostile logging loads are encountered, thereby reducing the risk of tool loss or damage. All recordings are saved in high fidelity to tool memory, permitting full decomposition and analysis in post processing. Examples of waveforms, dispersion curves, sonic logs, and anisotropy measurements are presented to demonstrate the quality of the acoustic recordings.
Study on the Behaviours of Settled Heavier Phase in Two Phase Flows in Pipelines
Authors: Koguna Aminu J. , Yeung Hoi , Lao Liyun 
Published: September 2015

Abstract
Pipelines transfer production fluids from the well head to the platform and from the platform to process facilities. Water, sand or liquids like condensate could settle at the bottom of pipelines especially at low flow velocities and this has implication for flow assurance. During shutdown the settled heavy liquid (e.g. water), could result in corrosion in pipelines, while following restart stages the settled water could form a water plug that could damage equipment, while settled sand could also form a blockage that needs to be dispersed into the flowing fluid. This study looked at cases of low water cut in oil flows and, low sand concentrations in water flows. Conductive film thickness probes were used to obtain oil and water interface height and the water film velocities in water in oil flows.
Similarly values for the sand in water, sand layer profiles and sand dune velocities were investigated respectively. Comparisons are made between two cases in order to gain better understanding of the dispersal process of low loading heavier phase in two phase flows.
A New Algorithm for Multiphase Fluid Characterization for Solvent Injection
Authors: Kumar Ashutosh , Okuno Ryosuke 
Published: September 2015

Abstract
Compositional simulation of solvent injection requires reliable characterization of reservoir fluids using an equation of state (EOS). Under the uncertainty associated with non-identifiable components, reservoir fluids are conventionally characterized on an ad-hoc basis in the absence of universal methodology. This is true even for relatively simple fluids involving only the gaseous (V) and oleic (L1) phases. No systematic method has been presented for characterization of more complex fluids, exhibiting three hydrocarbon phases: the V, L1, and solvent-rich liquid (L2) phases.
This paper presents a new algorithm for systematic characterization of multiphase behavior for solvent injection simulation. The reliability of the method comes mainly from the binary interaction parameters (BIPs) newly developed for the Peng-Robinson (PR) EOS to represent three-phase behavior, including critical endpoints, for n-alkane and CO2/n-alkane binaries. The regression part in fluid characterization broadly follows the concept of perturbation from n-alkanes, which was successfully applied for simpler two-phase fluids in our prior research. The algorithm, in its simplest form, uses only the saturation pressure and liquid density at a given composition and reservoir temperature.
Case studies are presented to demonstrate the reliability of the algorithm for 90 reservoir fluids and their mixtures with solvents. Predictions are compared with experimental data for up to three phases. Results show that the simple algorithm developed in this research enables the PR EOS to predict multiphase behavior in spite of the limited data used in the regression. It is straightforward to implement the algorithm in existing software that uses the PR EOS.
Forecasting of Steamflood Performance in a Heavy Oil Field
Authors: Rubin Eugene , Izgec Omer 
Published: September 2015

Abstract
Low oil recovery reached after more than 60 years of production in a rather deep heavy oil (9.5-11 °API) field in South America encourages looking for a thermal method (steamflood) which potentially promises a tenfold increase in the recovery factor.
Steamflood forecasting for such a large field is highly challenging. Direct thermal reservoir simulation seems impractical because of the size of the model (about 120 million grid-blocks). A recently developed correlation-based probabilistic technique has met the forecasting challenge. First, a relatively small set of thermal reservoir simulation runs with sector models provided a basis for production/injection correlations between key rates as well as cumulative quantities and the models' geologic and engineering input. All the runs included pressure depletion and steamflood stages. Next, about 350 forecasting elements (1 sq. km each) covered the entire Northern part of the field, which was subject of the forecasting; every element received probabilistic distributions of the key geologic parameters involved in correlations. Then, the Monte-Carlo simulation united the correlations with the distributions and allowed selecting combinations of the parameters corresponding to P10-P50-P90 probabilities of the dynamic performance. Reconstruction of oil and water production as well as steam injection P10-P50-P90 time-profiles completed preparation of the forecasting elements.
Reservoir depth and quality cut-offs restricted the area of the potential future steamflood application. For several sets of the cut-offs, wells were placed within the areas in accordance with inverted 7-spot patterns at either 8 or 24 acres/pattern. Every well adopted production or injection profiles from its forecasting element-host. Drilling timetable controlled the wells coming on primary production. Steamflood started in a 100-pattern cluster after 4-5 years of primary production. Heat management governed time-profile of steam injection into the cluster. On reaching a steam-oil-ratio cut-off, steam injection shifted to the next 100-pattern cluster. Summarizing individual well production or injection time-profiles, arranged in accordance with the drilling schedule, generated field P10-P50-P90 forecasts for several cases of interest.
Using Embedded Discrete Fracture Model (EDFM) and Microseismic Monitoring Data to Characterize the Complex Hydraulic Fracture Networks
Authors: Shakiba Mahmood , Sepehrnoori Kamy 
Published: September 2015

Abstract
Microseismic monitoring is widely used in petroleum industry to image the created hydraulic fracture networks. In this technology, the recorded seismic information during hydraulic stimulation is analyzed to locate the rock deformation and to characterize the failure mechanism. Over the last few years, various approaches have been proposed to calibrate the corresponding discrete hydraulic fracture networks (DFN) with the measured microseismic pattern to study long-term reservoir production. However, due to complexity of the problem and the limitations of reservoir simulators, the direct application of such complex DFNs has been highly restricted. Instead, the spatial extent of microseismic cloud has been often used as a direct measure to assess the efficiency of the treatment. Such interpretation techniques without further modeling and simulations of hydrocarbon production and pressure drainage fail to represent an accurate view of connectivity and complexity of the fracture system.
In this paper, we present a recently developed Embedded Discrete Fracture Model (EDFM) to capture the realistic geometry of fractures. In EDFM, each fracture plane is embedded inside the matrix gird and is discretized by the cell boundaries. Using EDFM, we study a series of reservoir simulation examples, in which the complex hydraulic fracture networks calibrated by microseismic monitoring are considered. We investigate different DFN realizations in both planar and complex fracture configurations. We explore the impact of network geometry and fractures properties on the overall performance of the reservoir.
The simulation results indicate that the efficiency of well treatment is strongly controlled by fractures connectivity and the distribution of conductivity within the network. When the spatial extent of microseismic cloud is fixed, by changing the degree of connectivity, a wide range of production response is observed. For instance, when the interconnection between the fracture planes is weak, the observed drainage volume is much smaller compared to the one predicted by microseismic monitoring. On the other hand, taking into account the role of aseismic deformations (such as tensile openings) improves the cumulative production. Even in the case of bi-wing hydraulic fracture planes, it is displayed that neglecting the effect of small-scale fissure openings may lead to underestimation of stimulation efficiency.
Although the microseismic monitoring depicts a preliminary view of the induced fracture network, more information can be obtained through numerical simulation of fluid transport inside the facture system. Modeling the complex DFNs shows that an accurate production forecast can be achieved using simulation models rather than direct application of total stimulated reservoir volume. Integrating the Embedded Discrete Fracture Model (EDFM) and the microseismic data provides a robust and efficient approach to investigate different DFN realizations.
Thermodynamic Analysis of Solvent Assisted Steam Injection
Authors: Memarzadeh Arash , Rahnema Hamid 
Published: September 2015

Abstract
The use of steam injection for high viscosity oil fields is popular in the petroleum industry due to its success in increasing bitumen recovery rates. Recent studies in the past decade, including simulations, experiments and pilot tests suggest that the co-injection of hydrocarbon solvents can further increase production rates over steam alone. However, the immiscibility and equations of state (EOS) discontinuity between hydrocarbon solvents and water makes predictions for thermodynamic property changes difficult. As a result, the selection criteria for finding the optimum molecular weight of the co-injecting solvent is often based on a “guess and check” approach through both reservoir simulators and laboratory testing.
In order to properly determine a beneficiary solvent for co-injection with steam, the thermodynamic principles and physical interactions between the separate phases of the injected fluids must be fully understood. Unfortunately, commercial thermal simulators do not accurately determine compositional changes within a thermal setting as such programs utilize K factor compositional equations which is far more error prone EOS based compositional equations. This research demonstrates the thermodynamic mechanisms occurring between the different phases of water and solvent through a thermodynamic simulation program. This program couples EOS with saturated water correlations to mechanistically model the characteristics of all fluids and phases individually while still considering their interactions. The composition and phase changes of the system during the heat transfer process are also identified, enabling EOS calculations to be updated with more accurate fluid data.
Through detailed calculations of thermodynamic processes, an explanation is given to exactly why temperature changes are observed in steam when in the presence of a light hydrocarbon. This allows for the fundamental understanding of the physical interactions that occur within the injected fluids of a solvent assisted steam injection, particularly in a controlled setting such as an experimental reservoir model. However the program may still be used independently from any experimentation to gain a conceptual understanding of the thermodynamic interactions between steam and solvent during a condensation process.
Performance of Fiberglass Casing and Tubing in Highly Corrosive Environments
Authors: Rauf Ahmed Abdul 
Published: September 2015

Abstract
The UER formation in the Dukhan Field, Qatar has an aquifer associated with it. Since the 1950's the UER aquifer has been used for water-flood source water, produced water disposal, and is a loss circulation zone for drilling purposes. Over a period of years the carryover-oil and bacterial contamination from drill cuttings have soured the formation which has led to many corrosion related problems such as surface casing failure, resulting in a well lifetime of 3-10 years. The conductor pipe in the Dukhan field suffers from tidal oxidation-corrosion and will not usually last longer than 5-8 years. These field results are confirmed by casing-inspection logs.
Our research proposal was to replace these with fiberglass casing and tubing. Any casing that is replaced would need to withstand similar reservoir conditions as the original steel, and fulfill the same collapse and burst pressure functions. Despite plenty of mechanical testing data available on fiberglass as a material, there is very little existing research on cementing fiberglass casing in sour environments. Therefore, a field-specific, quantative and mechanical test on fiberglass casing and tubingwas performed. Before conducting physical research, we compiled industrial advantages of fiberglass through fiberglass-manufacturerguarentees and product ratings. In the laboratory, we re-established the high resistance to corrosion of fiberglass, and demonstrated comparable compressive and shear strengths of fiberglass piping to that of steel.
Our research revealed that latex cement would bond to the fiberglass casing as good as the expensive resin-based cement. The cement bonded very well and held even after until the piping had failed under compression. Surface casing and conductors made of fiberglass would not only be cheaper to transport and install, but also more resistant to all forms of corrosion, lighter to handle and easier to push into deviated or horizontal wells. (Williams 1987). Overtime, there will be a lower cost of corrosion-control and casing remediation. Indeed, fiberglass casing and tubing can be employed in the place of steel not only in the UER formation, but in a large number of highly corrosive environments, both downhole and in surface facilities.
Conceptualizing a Novel Method of Perpetual Energy Source from Gas Hydrates
Authors: Steffones K 
Published: September 2015

Abstract
Methane Gas Hydrates comprise of a single CH4 molecule enclosed in a cage of H2O molecules. These ice-like materials which represent the largest reserves of unconventional natural gas are formed under low temperatures and high pressure generally in the permafrost and the ocean floor region. Out of the many methods under development for production of methane from natural gas hydrates, one of the most promising methods involves the injection of a CO2 into a gas reservoir. By exposing the CH4 hydrate structure to a thermodynamically preferred hydrate former, CO2, it has been observed that a spontaneous displacement and conversion from methane hydrate to CO2 hydrate takes place. Many experiments have proved that large cavities of hydrates prefer occupation by CO2, giving out CH4. This study aims to evaluate the possibility of converting a CO2 hydrate formed in the recovery of CH4 back into CH4 and increasing the recovery & thus improving the efficiency of the methane recovery from CH4 hydrates. If the conditions in the reservoir prevails well then the CH4 formed can be converted to CH4 hydrate hence forming a ‘Perpetual Energy Source’. Microbial agents (psychrophilic methanogens) will be used for the in-situ conversion of CO2 to CH4 (requiring the presence of H2). This conversion process reduces CO2 emission and thus protects the environment. Further this study will develop and evaluate a conceptual model for stated the cyclic process. Development of such system which would combine the advantages of the two processes which will create a form of perpetual energy source and would substantially increase the production of natural gas from hydrate reservoirs and will act as form of Carbon-capture and sequestration(CCS). As conventional energy sources are fast depleting, energy requirements and the menace of global warming are rising the corner, it is about time we shift our attention to new and emerging sources like gas hydrates that provide the solution to satisfying the future's needs. This system will provide reliable and affordable energy so that economies of the world can prosper.
A 13-Year-Old Girl in Trigeminy During Anesthesia for Outpatient Dental Surgery: A Case Report
Authors: Waxman Bryan Neil 
Published: September 2015

Abstract
A 13-year-old girl presented to a private office for dental rehabilitation under general anesthesia. The patient had a previous uneventful anesthetic 5 years prior in the same office by another dental anesthesiologist. The patient was highly anxious and would not allow monitors placed prior to induction. After an uneventful mask induction with sevoflurane, nitrous oxide, and oxygen, monitors were placed and a 22-gauge intravenous cannula inserted. The initial rhythm on the electrocardiogram was trigeminy interspersed with normal sinus rhythm. The volatile anesthetic sevoflurane was discontinued immediately, and intravenous anesthesia was started but still the patient was consistently entering trigeminy. The patient was always hemodynamically stable and never hypoxic. An in-depth discussion of the case and discussion of ventricular dysrhythmias is presented.
Oral Sedation Postdischarge Adverse Events in Pediatric Dental Patients
Authors: Huang Annie , Tanbonliong Thomas 
Published: September 2015

Abstract
The study investigated patient discharge parameters and postdischarge adverse events after discharge among children who received oral conscious sedation for dental treatment. This prospective study involved 51 patients needing dental treatment under oral conscious sedation. Each patient received one of various regimens involving combinations of a narcotic (ie, morphine or meperidine), a sedative-hypnotic (ie, chloral hydrate), a benzodiazepine (ie, midazolam or diazepam), and/or an antihistamine (ie, hydroxyzine HCl). Nitrous oxide and local anesthesia were used in conjunction with all regimens. After written informed consent was obtained, each guardian was contacted by phone with specific questions in regard to adverse events following the dental appointment. Out of 51 sedation visits, 46 were utilized for analysis including 23 boys and 23 girls ranging from 2 years 2 months to 10 years old (mean 5.8 years). 60.1% of patients slept in the car on the way home, while 21.4% of that group was difficult to awaken upon reaching home. At home, 76.1% of patients slept; furthermore, 85.7% of patients who napped following the dental visit slept longer than usual. After the appointment, 19.6% exhibited nausea, 10.1% vomited, and 7.0% experienced a fever. A return to normal behavior was reported as follows: 17.4% in <2 hours, 39.1% in 2–6 hours, 28.3% in 6–10 hours, and 15.2% in >10 hours. Postdischarge excessive somnolence, nausea, and emesis were frequent complications. The time to normality ranged until the following morning demonstrating the importance of careful postdischarge adult supervision.
Population structure and distribution of Abies spectabilis (D. Don) in Central Nepal Himalaya: A comparison with the total woody vegetation of the forests at the three different elevation ranges in Manang District
Authors: Kharal D. K. , Bhuju D. R. , Gaire N. P. , Rayamajhi S. , Meilby H. , Chaudhary A. 
Published: September 2015

Population structure and distribution of vegetation are often affected by elevation induced climate variation in the Himalaya. This research aims at assessing the population structure and distribution of Abies spectabilis in three different elevation sites within the forests areas in Manang District of central Nepal. Vegetation sampling was conducted during Sept-Oct 2012 and the population information of all the woody vegetation from a total of 59 concentric circular sampling plots of 10 m radii along the transect line were collected. The middle elevation site was characterized by the highest density of seedlings (15,044/ha), saplings (1,629/ha), poles (272/ha) and trees (179/ha) of all woody vegetation. In this elevation, the highest proportion was contributed by A. spectabilis (54%) at combined-level in spite of the lack of large-sized stems (dbh > 70 cm). The proportion of A. spectabilis stem was nearly one-fourth of all the woody vegetation while its lowest proportion (15.5%) was found at the lower elevation at combined-level. On the contrary, its basal area proportion was nearly the half of all the woody vegetation at the lower elevation site, nearly one-third at the middle elevation site and less than 10% at the upper elevation site. There was a significant variation in mean density and basal areas of all stem categories among the sampled sites except the seedling density of all the woody vegetation between the lower and the middle elevations. The stem distribution of all the woody vegetation including A. spectabilis demonstrated the characteristics of normal (sustainable) forest in Manang District. The presence of only small-sized trees with good recent regeneration of A. spectabilis in the upper treeline ecotone revealed stand densification as well as its potential for upward migration in response to environmental change including climate change in future.Banko Janakari; A Journal of Forestry Information for Nepal Vol. 25, No. 1Page: 3-14