bluuebunny/crossref_metadata_2025_split huggingface dataset:
KERAGAMAN JENIS BURUNG AIR DI TAMAN NASIONAL WASUR, MERAUKE
Authors: Winara Aji 
Published: March 2017

Water birds is one of the featured biodiversity of Wasur National Park in Papua. Rawa Donggamit and Ndalir Beach is a habitat for water birds closest to residential areas and became the object of tourist attraction. This study aims to determine the species diversity of water birds and habitat conditions in Wasur National Park. The research was conducted in October 2010. The method was used is the exploration field. The results showed as many as 56 species of birds from 15 families found scattered in the area of Rawa Donggamit (50 species) and Ndalir Beach (22 species). The diversity level of bird classified as moderate with Shannon-Wienner value index (H ') of 1,72 to 2,81, Margalef richness index (R') is high for Rawa Donggamit (R '= 6,32) and moderate for Ndalir Beach (R '= 2,64). There are significant differences in the diversity between locations with Jaccard index value of 0,28. The condition of the habitat of water birds in the Rawa Donggamit suffered invasion some plant species with the widest level of invasion is kind of Fimbristylis sp. 25% of the forest habitat, while bird habitat in Ndalir beach was not much disturbed.Burung air merupakan salah satu keanekaragaman hayati unggulan di Taman Nasional Wasur Papua. Rawa Donggamit dan Pantai Ndalir merupakan habitat burung air terdekat dengan wilayah pemukiman dan menjadi objek daya tarik wisata. Penelitian ini bertujuan untuk mengetahui keragaman jenis burung air dan kondisi habitatnya di Taman Nasional Wasur. Penelitian dilaksanakan pada bulan Oktober 2010. Metode penelitian yang digunakan adalah penjelajahan lapangan. Hasil penelitian menunjukkan sebanyak 56 jenis burung dari 15 famili dijumpai tersebar di wilayah Rawa Donggamit (50 jenis) dan Pantai Ndalir (22 jenis). Tingkat keragaman jenis burung tergolong sedang dengan nilai indeks Shannon-Wienner (H’) sebesar 1,72-2,81, Indeks kekayaan Margalef (R’) tergolong tinggi untuk Rawa Donggamit (R’= 6,32) dan sedang untuk Pantai Ndalir (R’= 2,64). Terdapat perbedaan keragaman yang nyata antar lokasi dengan nilai Indeks Jaccard sebesar 0,28. Kondisi habitat burung air di Rawa Donggamit mengalami invasi beberapa jenis tumbuhan dengan tingkat invasi terluas adalah jenis Fimbristylis sp. mencapai 25 % dari luas habitat, sedangkan habitat burung di Pantai Ndalir tidak banyak terganggu.
Optimal Consumption and Portfolio Decision with Heston’s SV Model Under HARA Utility Criterion
Authors: Wang Chunfeng , Chang Hao , Fang Zhenming 
Published: March 2017

Abstract
This paper studies the optimal consumption-investment strategy with Heston’s stochastic volatility (SV) model under hyperbolic absolute risk aversion (HARA) utility criterion. The financial market is composed of a risk-less asset and a risky asset, whose price process is supposed to be driven by Heston’s SV model. The risky preference of the individual is assumed to satisfy HARA utility, which recovers power utility, exponential utility and logarithm utility as special cases. HARA utility is of general framework in the utility theory and is seldom studied in the existing literatures. Legendre transform-dual technique along with stochastic dynamic programming principle is presented to deal with our problem and the closed-form solution to the optimal consumption-investment strategy is successfully obtained. Finally, some special cases are derived in detail.
Using Grey Relational Analysis with Entropy to Predict the International Financial Center of China
Authors: Jiang Hang , Lin Jan-Yan , Jiang Peng 
Published: March 2017

Abstract
The establishment of the China Pilot Free Trade Zone (FTZ) has significantly promoted international trade, financial development, and economic growth. Building international financial centers (IFCs) satisfies the demand for FTZs to facilitate financial development, as well as promoting economic growth. Thus, successfully predicting the next IFC in China under the FTZ framework is an important issue. In this study, we applied grey relational analysis combined with entropy method to predict potential IFCs among seven FTZ cities. According to the results, our interesting findings include: 1) the “total stock turnover”, “total value of imports and exports”, and “Foreign Direct Investment (FDI)” are key indicators for determining future IFCs; 2) among seven cities, Shenzhen and Tianjin are highly likely to become the next IFCs, while Shanghai is already an IFC.
Estimating Effective Fracture Pore Volume From Flowback Data and Evaluating Its Relationship to Design Parameters of Multistage-Fracture Completion
Authors: Fu Yingkun , Dehghanpour Hassan , Ezulike Dannel Obinna , Jones R. Steven 
Published: March 2017

Summary
Flowback data from seven multifractured horizontal tight oil/gas wells in Anadarko Basin show two separate regions during the single-phase water production. Region 1 shows a dropping casing pressure, and Region 2 shows a flattening casing pressure. This paper investigates the flowback behavior of the two regions, and illustrates how flowback data can be interpreted to estimate effective fracture pore volume, and to investigate its relationship to completion-design parameters. We construct diagnostic plots to understand the physics of Regions 1 and 2. Region 1 represents pressure depletion in fractures, and Region 2 represents the hydrocarbon breakthrough into the effective fracture network. The results of our analyses indicate that the duration of Region 1 depends on initial reservoir pressure and hydrocarbon type. We apply a previous flowback model (Abbasi et al. 2012, 2014) on Region 1 to estimate effective fracture pore volume, and also propose a procedure to estimate fracture compressibility by use of diagnostic-fracturing-injection-test (DFIT) data. The results suggest that the estimated effective fracture pore volume is very sensitive to fracture compressibility, and is generally larger than the final load-recovery volume, and less than the total injected-water volume. The results also suggest that most of the effective fractures are unpropped, and host the nonrecovered fracturing water. We investigate the relationship between the estimated effective fracture pore volumes and completion-design parameters, including total injected-water volume, proppant mass, gross perforated interval, and number of clusters, by use of the Pearson correlation-coefficient method. The results show that total injected-water volume, gross perforated interval, and the number of clusters are among the key design parameters for an optimal fracturing treatment. Higher total injected-water volume and closer cluster spacing generally lead to a larger effective fracture pore volume.
A Novel Versatile LDHI to Treat Multiple Conditions
Authors: Lan Qiang , Monteiro Deepak , Ceglio Mark , Krishnamurthy Pushkala 
Published: March 2017

Abstract
Oil and water conditions can have significant impact on the performance of anti-agglomerant (AA) low-dose hydrate (gas hydrate) inhibitors (LDHIs). For example, chemistry that performs well in high water cut (WC) and high salinity might not be effective in conditions of low salinity. This paper discusses development of versatile AA hydrate inhibitor chemistry effective under various conditions, including condensate water/low WC, certain salinity/high WC, etc. A systematic study was also conducted on the structure-property relationship of hydrate inhibition performance and water quality.
A rocking cell was used to test the hydrate inhibition performance of the chemicals. The tests were conducted using black oil and condensate from a field under three different conditions using actual field operating temperatures, pressures, and water salinities. The results of the tests were graded using a pass (flowable hydrate slurries) or fail system (plugged systems) based on the visual observation of the movement of the ball and an indirect measurement of the viscosity of the oil/water/hydrate mixture. Water quality was also analyzed at different conditions by means of direct visual observation.
The systematic study discussed in this paper helps demonstrate that the structure of the molecules has a significant effect on performance. For such surfactant type molecules, the head and the length of the tail should be properly modified to work effectively for particular oil and salinity. Such knowledge enabled the development of products to treat single particular conditions. More importantly, it also led to development of a product capable of treating multiple conditions at the same time. The formulation presented here also helps improve the overboard water quality so that an emulsion breaker is not necessary to manage it, helping to minimize additional costs.
The AA chemistry discussed can be adjusted to a wide range of conditions from low to high WC and salinity. It is particularly advantageous when several different conditions exist for certain fields. A single product can be used, thus helping reduce the costs associated with using multiple products, as well as reducing storage space necessary on platforms.
On-Demand Water Control: Molecular Host-Guest Interaction for In-Situ Modification of Formation Fluid Permeability
Authors: Recio Antonio , Eoff Larry , Lewis Christopher , Reddy B. R. 
Published: March 2017

Abstract
Hydrophobically modified hydrophilic polymers (HMHPs) have numerous applications in the petroleum industry, among which stand out relative permeability modifiers (RPMs) for acid diversion, drilling, fracturing, water control, water-injection profile modification, or improved oil recovery (IOR) operations. The efficacy of the polymeric RPM is attributed to a bimodal mechanism of action, which involves the association of the hydrophobic appendages in addition to adsorption of the amphoteric material to the formation surface. As a result, one challenge associated with the use of HMHPs is the pressure increase often observed when the material enters the formation. A second limitation is the inability to reverse the effect of the treatment fluid, which can be significant when the HMHP is overdisplaced, resulting in a reduction of flowback fluid, or when operational requirements call for placement of a deactivated HMHP that can be selectively activated at a desired time and location.
Because of the self-diverting nature of the HMHP discussed in this paper, field deployment has been limited to near-wellbore (NWB) applications. Within this context, a linear surfactant additive [sodium dodecyl sulfate (SDS)] has been an effective mitigation strategy against such self-diverting characteristic; however, this also inhibits other desirable HMHP properties. Restoration of the native RPM properties was achieved using a surfactant control agent that allows on-demand RPM reactivation. Recently, it was realized that the sodium dodecyl sulfate has a much higher affinity for hydroxypropyl-β-cyclodextrin (HPCD) than HMHP.
This paper discusses developments that allow for improved injectivity of HMHPs when used as RPMs for water-control operations. In addition, this study attempts to advance the existing understanding of the performance and associative mechanism of action of RPMs. Currently, there is a lack of consensus about the role hydrophobic modifications play in HMHP performance. Using host-guest attraction, the nature of the hydrophobic moieties is revealed, which compliments the current body of literature related to the use of HMHP in the petroleum industry. To this end, adsorption, fluid loss, and coreflow results prove the increased affinity of the surfactant for HPCD serve to release HMHP from the HMHP/linear-surfactant complex, reactivating the HMHP to its original associative mechanism-based RPM-performance profile.
Iron Sulfide Precipitation and Deposition under Different Impact Factors
Authors: Liu Y. , Zhang Z. , Bhandari N. , Yan F. , Zhang F. , Ruan G. , Dai Z. , Alsaiari H. A. , Lu A. Y. , Deng G. , Kan A. T. , Tomson M. B. 
Published: March 2017

Abstract
Iron sulfide scale is a serious concern to flow assurance in the oil and gas production, which is especially true for oil wells with high concentration H2S. FeS is oil wet and can cause emulsions, leading to operational problems and impairing oil quality. FeS accumulation on tubular can reduce oil production efficiency and may cause further corrosion to tubulars. To tackle FeS problems, it is essential to understand how FeS precipitates and deposits under various operation conditions.
In this study, we developed a strictly anoxic plug flow reactor to study FeS precipitation kinetics. Argon gas is used to remove oxygen in the solution and apparatus, and acetic acid and sodium acetate are used for pH control. We studied the impact of temperature, ionic strength, Fe(II) to S(-II) concentration ratio, steel type, and FeS dispersant on FeS precipitation kinetics and deposition.
It was observed that FeS precipitation is pseudo 1st order when Fe(II) to S(-II) concentration ratio is below 1:5, although the precipitation rate is extremely fast. At temperature range of 23 - 100 °C, freshly precipitated FeS was found to be mackinawite or amorphous FeS. A strongly attached FeS layer can form on both mild steel C1018 and corrosion resistant hastelloy C-276 alloy. FeS precipitation kinetics can be strongly accelerated by temperature or IS increase. [Fe(II)] / [S(-II)] ratio surprisingly does not affect FeS precipitation kinetics. FeS deposition can be significantly inhibited by low temperature, extra high IS (≥ 4 mol/L), and a FeS dispersant. H2S corrosion of mild steel C1018 coupon and FeS scale retention on the coupon were also investigated. We found that high temperature and moderately high IS (e.g. 2 mol/L) promotes H2S corrosion and FeS scale retention, but the FeS dispersant can effectively inhibit FeS scale retention.
This study contributes valuable data of FeS precipitation kinetics and deposition, which is rarely reported but essential for FeS prediction. Also, it has never been systematically investigated howdifferent factors affect FeS precipitation and deposition, but it is rather valuable for FeS control in the oil and gas production. Moreover, the developed strictly anoxic apparatus provides a reliable way for FeS research and FeS inhibitor or dispersant testing.
Employing an Arrhenius Rate Law to Predict the Lifetime of Oilfield Resins
Authors: Jones Paul , Boontheung Charm , Hundt Greg 
Published: March 2017

Abstract
In recent years, the use of polymer resins in oil and gas well cementing operations has increased. Unlike cement, resins do not have wide spread, vast case histories spanning 100 years, which leads to questions about their lifespan. The degradation kinetics of a commercially available oilfield resin system was studied and modeled to predict resin system lifetime as a function of temperature. Chemical degradation was monitored above the glass transition temperature using isothermal thermogravimetric analysis (TGA). The rate of weight change as a function of temperature was used to determine the reaction rate constant at various temperatures. This information was used to determine the activation energy and pre-exponential constant. These important parameters were then used to model the degradation reaction using an Arrhenius equation to predict the material lifetime as a function of service temperature. For selected resin systems, the degradation kinetics data were also collected at elevated pressure. The rate of weight loss strongly increased with increasing temperature; however, in experiments where pressure was applied under isothermal conditions, this rate was observed to be reduced. The degradation process was observed to follow a first order rate law. Comparing calculated rate constants to experimentally obtained rate constants yielded good correlation. The formulation of the resin system as well as component selection was observed to have a significant effect on material lifetime at downhole temperatures. The glass transition temperature of the resin system was not determined to directly correlate with degradation kinetics, and in some cases, increasing the glass transition temperature was not determined to increase the lifetime of the resin system at the temperature range evaluated.
This work provides an experimental outline for the necessary data collection and evaluation techniques to predict the lifetime of various resin systems at downhole temperature conditions using classical chemical kinetic equations. This allows the service company and operator to determine under what conditions and applications usage of resin systems is appropriate.
Analysis and Optimization of H2S Scavenger Systems Using X-Ray Fluorescence Spectroscopy
Authors: Horton Dave , Bakuska Derrick , Soderberg Jeff 
Published: March 2017

Abstract
Field methods are available for the determination of dithiazine content in spent hydrogen sulfide scavengers. While these methods are useful, accuracy of the assay and interference from other chemical species or matrix effects can limit the utility of these methodologies. Due to the limitations of these methods, alternate analytical techniques were investigated. An analytical method has been developed using x-ray fluorescent (XRF) techniques that rapidly provides accurate results for total sulfur content in these scavengers. The method uses analytical equipment commercially available for sulfur in oil analysis. Sulfur compound speciation is not possible with XRF techniques, however speciation is not a critical factor in optimization as the goal is to maximize sulfur uptake while limiting dithiazine content and available sulfur to form dithiazine. The method finds application in any other scavenger solutions where soluble sulfur species are present, for example, alkanolamines or solvent based such as polyethylene glycol methyl esters. Instrument calibration is dependent upon the matrix being analyzed; however the method is robust within similar matrices of material. Instruments used for this application are light, portable and easy to use in a laboratory environment or a field environment. The method has been applied in a variety of locations in the United States and Canada to aid in optimization of scavenger application. Verification of the accuracy of the method was confirmed by random sampling and combustion analysis of the random sample of spent scavenger at Alberta Sulphur Research.
A Predictive Equation-of-State for Modeling Microemulsion Phase Behavior with Phase Partitioning of Co-Solvent
Authors: Basilio Enoc , Mu Binbin , Jin Luchao , Jamili Ahmad 
Published: March 2017

Abstract
Co-solvents are widely used to improve chemical flooding formulation design, but their partitioning between phases has great impacts on microemulsion phase behavior. Therefore, it is critical to accurately model microemulsion phase behavior with phase partitioning of co-solvents in a compositional chemical flooding simulator, in order to correctly predict oil recovery and better evaluate the performance of the designed formulation.
We use the physics based HLD-NAC EOS implemented with the co-solvent partitioning model developed by Biais et al. (1981) and Hirasaki (1982) to model microemulsion phase behavior with cosolvents. The HLD-NAC model can determine microemulsion phase type by correlated phase behavior dependent variables and can calculate the overall interfacial area and sizes of micelle by characterized surfactant properties. To accurately estimate the interfacial area taking into account the contribution of co-solvents, an interfacial pseudophase composed of surfactant and co-solvents is defined. Partitioning coefficients of co-solvents between interfacial pseudophase and bulk pseudophase are experimentally measured. This novel model has only one fitting parameter, which is the tail length (Lsurf) of surfactant mixtures.
We used five microemulsion systems to examine the developed approach. Solubilization ratios under a salinity scan of these systems are reproduced. Without using the co-solvent partitioning model, the matched Lsurf is dramatically underestimated for each system due to assuming all co-solvents are adsorbed onto the interface. With the improved model, the matched Lsurf is more physically representing the actual surfactant tail length. Microemulsion compositions predicted by the novel HLD-NAC EOS is in a good agreement with the experimentally measured microemulsions at all phase behavior types from Winsor Type I, through Winsor Type III to Winsor Type II. The results prove the physics based HLD-NAC EOS coupling with the thermodynamic co-solvent phase partitioning model can accurately simulate phase behavior of surfactant/co-solvent/brine/crude oil systems.
The novelty of the present work is to exercise the physics-based HLD-NAC EOS to model the phase behavior of the aforementioned systems considering co-solvent partitioning. The new model can be used in compositional chemical flooding reservoir simulation to improve the predictability of surfactant floods.
Development and Execution of Sand Control Gas Completions in the York Field, UK Southern North Sea
Authors: Langford Marc , Couper Christopher , Tovar Juan 
Published: March 2017

Abstract
York field is located in the Southern North Sea (SNS), within the UK offshore license blocks 47/2a, 47/3a, 47/3d, and 47/3e. The field lies 40 km east of the Humberside coast in a water depth of 42 m, approximately 25 km northeast of the Yorkshire coast and adjacent to the Rough Gas storage field.
York field has been in production since 2012. The field consists of four production wells from a normally unmanned installation (NUI). All four wells have active downhole sand control and long horizontals drilled and completed in the reservoir section.
This paper presents the design phase and execution for sand screen completions and provides an in depth process of the selection criteria for the lower completions performed in York field.
Findings are presented along with analyses of the design methodology and installations to date. In addition, results of the well post-completions data are discussed.