bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical Alteration of Near-Wellbore Mineralogy for Improved Squeeze Performance
Authors: Fleming N.. , Ramstad K.. , Hoeth L. Wichers , Kidd S.. 
Published: August 2010

Summary
Squeezing of clean, high-permeability reservoirs frequently results in relatively short treatment lifetimes because of the low inhibitoradsorption rates achieved. One of the main controls on inhibitor retention is near-wellbore mineralogy. Clay-rich reservoirs that contain abundant kaolinite, for example, often have long squeeze lifetimes because enhanced inhibitor adsorption can occur on the clay surface. The occurrence of calcium carbonate (CaCO3) cement in the near-wellbore region can also enhance inhibitor retention by forming a Ca2+/inhibitor complex.
Previously published research (Fleming et al. 2009a) demonstrated the potential to mechanically alter the near-wellbore region through incorporation of low concentrations of kaolinite and organosilane. The data presented in the present work show that the additional incorporation of calcium carbonate provides a step change in the potential squeeze lifetimes achieved. This paper will present the results of using low, nondamaging concentrations of kaolinite and calcium carbonate particles in the preflush followed by scale inhibitor and organosilane in the main treatment. The kaolinite particles are retained in the near-wellbore region by the organosilane and enhance the number of potential sites for inhibitor adorption. At the same time, dissolution of the calcium carbonate particles by the acidic scale inhibitor forms a Ca2+/inhibitor complex that further enhances inhibitor retention.
A review of the technology performance envelope has been made through coreflooding that includes optimizing the concentration of injection particles vs. permeability, the ratio of injected kaolinite to carbonate particles, and performance at elevated temperature (175°C) along with an assessment of how often a well would require retreatment with particles. The latter has involved successive coreflooding of the same plug with the full treatment package followed by brine flowback and retreatment with scale inhibitor alone or with organosilane. This information can be used by the assets in their evaluation on potential use of the technology.
Injection of Water Above Gas for Improved Sweep in Gas EOR: Nonuniform Injection and Sweep in 3D
Authors: Jamshidnezhad Mohammad , van der Bol L.. , Rossen W.R.. R. 
Published: August 2010

Summary
In gas-injection enhanced oil recovery (EOR), simultaneous injection of water and gas from parallel horizontal wells with water injected from the upper well [sometimes called modified simultaneous water and gas (SWAG) injection], can give deeper penetration of gas before gravity segregation than SWAG from the same well. Most previous studies of this process were limited to 2D, in which the injection rate is uniform along each well.
In 3D, we find that gas injection can be far from uniform, even in homogeneous reservoirs—which are the focus of this study. If gas injection is nonuniform in homogeneous reservoirs, it surely would be so in heterogeneous reservoirs. In some cases, there is an inherent instability in uniform injection along the gas well, even as the water well continues to inject nearly uniformly along its length. In our results, the uniformity of gas injection increases with increasing total injection rate and decreasing vertical distance between gas- and water-injection wells. The instability leading to nonuniform injection depends on the relation between gas saturation and gas relative permeability; we speculate that effects of gas flow on hydrostatic pressure, and therefore on gas-injection pressure, may also play a role. We find that in some cases, lateral movement of gas from the injection point partially mitigates the effects of nonuniform gas injection. Injecting gas from separate, independent segments along the horizontal well improves sweep somewhat by increasing the number of points at which gas exits the well.
Simulation and Optimization of Trapping Processes for CO2 Storage in Saline Aquifers
Authors: Nghiem Long , Shrivastava Vijay , Kohse Bruce , Hassam Mohamed , Yang Chaodong 
Published: August 2010

Summary
This paper describes the modeling of the main processes for CO2 trapping in saline aquifers, namely solubility trapping, residual gas trapping and mineral trapping. Several important aspects of CO2 storage are presented. It has been found that the total amount of CO2 trapped as a soluble component, and as residual gas, can be enhanced by injecting brine above the CO2 injector. An optimization technique is used to adjust the location and rate of the brine injector to maximize the total amount of CO2 trapping. The security of the trapping process is then evaluated by taking into account the leakage of mobile CO2 through the caprock. For long-term CO2 storage, the conversion of CO2 into minerals is found to depend on the pre-existing minerals in the aquifer that provide the necessary ions for the reactions to occur.
Diffusivity of Citric Acid During its Reaction With Calcite
Authors: Alkhaldi Mohammed H. , Sarma Hemanta K. , Nasr-El-Din Hisham A. 
Published: August 2010

Summary
The mass transfer process during the reaction of citric acid with calcite was investigated using a rotating disk apparatus. The effects of disk rotational speed, initial citric acid concentration and temperature on the effective diffusion coefficient of citric acid were examined.
Using various citric acid concentrations (1 wt%, 2 wt%, 5 wt% and 7.5 wt%), the diffusion coefficient of citric acid was calculated at 25°C, 40°C and 50°C. The effective diffusion coefficient of citric acid was found to be a function of the interplay between the calcium citrate precipitation and the presence of the counter-calcium ions. At high-initial acid concentration (5 wt% and 7.5 wt%), the effects of calcium citrate precipitation and counter-calcium ions were significant and the calculated citric acid diffusion coefficients were not comparable with those obtained using the rotating disk. However, the effects of both the calcium citrate precipitation and the counter-calcium ions on the citric acid diffusivity were minimal at low-initial citric acid concentrations.
The effect of temperature on the diffusion coefficient of citric acid at a constant citric acid concentration was found to follow Arrhenius law, and the activation energy was 37.9 kJ/mol.
A Method for Estimating Hydrocarbon Cumulative Production Distribution of Individual Wells in Naturally Fractured Carbonates, Sandstones, Shale Gas, Coalbed Methane and Tight Gas Formations
Authors: Aguilera Roberto 
Published: August 2010

Summary
A method, based on factual observations of naturally fractured reservoirs in several countries, is presented for estimating distribution of hydrocarbon cumulative production in wells drilled in fractured reservoirs of Types A, B or C. These observations indicate that in reservoirs of Type C, most of the cumulative production is provided by just a few wells, while the majority of the wells contribute a small part of the reservoir cumulative production. In reservoirs of Type B, the number of wells contributing significantly to cumulative production becomes larger relative to the case of Type C reservoirs. Finally, in reservoirs of Type A, a large number of wells contribute to field production, as compared with Type B reservoirs.
The method is shown to be useful for tackling problems of practical importance in naturally fractured reservoirs, including performing or not performing infill drilling, estimating the variation in cumulative hydrocarbon production per well in a given reservoir and estimating the number of wells that might be required for a given field hydrocarbon recovery. The method is illustrated using data from various fractured reservoirs, including the Barnett shale and sandstone reservoirs in the United States, carbonate reservoirs in Mexico and Venezuela and coalbed methane reservoirs and tight gas sands in Canada.
Reservoir Modelling of Complex Geological Systems--A Multiple-Point Perspective
Authors: Eskandari Kiomars , Srinivasan Sanjay 
Published: August 2010

Summary
Accurate characterization of sub-surface oil reservoirs is an essential prerequisite to the design and implementation of enhanced oil recovery (EOR) scenarios. Specifically, in reservoir characterization, integrating static and dynamic data into reservoir models to construct accurate and realistic models has received considerable attention. Unlike most of the conventional geostatistical approaches of integrating data into reservoir models that are based on semi-variograms (two-point statistics) as a measure of spatial connectivity, a complete multiple-point (MP) statistic framework is presented in this paper. In contrast to two-point statistic methods, MP statistics-based methods are capable of reproducing curvilinear geological structures. The algorithm starts with extracting MP statistics from training images (TI) using an optimal spatial template. After collecting different patterns and building the MP histogram, the pattern reproduction process commences. This process begins from data locations and then grows to fill the whole reservoir domain. The algorithm accounts for three main practical issues: uncertainty in geological scenarios, scanning template and non-stationarity. The MP statistics algorithm (growthsim) is capable of integrating data from multiple data sources. Among these data types is dynamic data or flow history.
The conventional approach to integrate production information into reservoir models is by iterative perturbation of the reservoir model until the production history of the reservoir is matched. Iterative methods have been applied till date to random fields that are completely characterized by a two-point co-variance function. In contrast, this paper presents a forward modelling approach that investigates history matching within a MP modelling framework. A novel technique implemented in this research is based on the merging of MPs inferred from history matched and geological models. Pattern growth is performed subsequently by sampling from the merged MP histograms. History matched models using the presented approach show an excellent agreement with underlying geological descriptions and match production history.
Valuation of Oil Properties
Authors: Sheldon Dean H. 
Published: August 2010

Introduction
Those of the oil industry, who are concerned with the earning power of oilproducing properties, visualize a valuation report as a rather stereotypedpresentation of data in a form that engineers use to present the results of ananalysical engineering appraisal. Specifically an engineering appraisal is anestimate of future recoverable oil and the cash profit to be derived from theproduction and sale of that oil. It should present with clarity the differencebetween factual material and the opinions formed from the analysis of thatmaterial. In presentation the engineer should keep in mind the purpose of theappraisal and the background of the people to whom the report is addressed.

Factors Considered
The fundamental features of an engineering appraisal for oil producingproperties are:
The type of interest in oil production that is being appraised and thecontents of the documents which create the interest.
The acquisition of data on the physical aspects of the oil reservoir and theincome and expenses that are connected with the removal and marketing of theoil and its associated hydrocarbons and the use of such information to forecastthe probable future earnings of the property.
There are many types of interest that may exist in a piece of oil producingland. There is a mineral interest; a landowner's interest, an overridingroyalty interest, an operating or lessee interest, sometimes called the workinginterest, a carried working interest, and a participating interest.
Each has a distinctive character determined by the wording of the legaldocument or contracts which create and transfer its ownership from party toparty. Careful consideration of all the terms of a lease and their effect onthe earning power of an oil property from a lessor and lessee's point of viewis not feasible. Nor is it proper to attempt a review of the effect manyfeatures of operating agreements and assignments may have on the worth ofvarious interests in oil production. A brief examination of some of the termscommonly found in various contracts concerning oil properties might be ofinterest to engineers.
Covered Grains in Naked Oat: Environment and Herbicide Effects
Authors: Lanoie Nathalie , Vanasse Anne , Collin Jean , Reid Judith Frégeau , Pageau Denis , Lajeunesse Julie , Durand Julie 
Published: August 2010

ABSTRACTNaked oat (Avena sativa L.) grown in Québec, Canada, produces an average of 10% covered grains. The objectives of this study were to evaluate the effects of environment, herbicide, and genotype on the proportion of covered grains, to study the relation between the presence of awns and the proportion of covered grains, and to determine the location of covered grains on the plant (tiller) and on the panicle. Eight oat lines were evaluated over 2 yr at four experimental sites. Each line was treated with bromoxynil/MCPA, dicamba/MCPA, or thifensulfuron methyl/tribenuron methyl applied at Zadoks 12–13 and compared to a hand‐weeded check. The highest percentages of covered grains, 5.5 and 6.9%, were found at different sites in 2006 and 2007. The application of dicamba/MCPA increased the percentage of covered grains in the lines normally producing a higher proportion of covered grains, but low producing lines were less affected. Minor differences were found among the other weed control treatments. No relation was found between the presence of awns and the proportion of naked grains. Covered grains were mostly produced on the main stem and their position on the panicle depended on genotype and weed control treatment.
Agronomic and Seed Characteristics of Soybean Lines with Alleles for Modified Glycinin Concentration
Authors: Jenkinson Jonathan E. , Fehr Walter R. 
Published: August 2010

ABSTRACTSoybean [Glycine max (L.) Merr.] genotypes have been developed with increased β‐conglycinin (BC) and reduced glycinin to improve the quality and health benefits of food products containing soybean protein. The changes in protein composition are due to the five recessive alleles, gy1, gy2, gy3, gy4, and gy5, that modify glycinin concentration. The objective of this study was to evaluate the influence of the gy alleles on protein composition and agronomic traits. Nineteen lines in each of eight genotypic classes involving different combinations of gy alleles from five populations were evaluated for protein composition, seed yield, and maturity in 2008.The BC concentration of lines was maximized with the gy1,2, gy4, and gy5 alleles, but the gy3 allele also was required to obtain 0 g kg−1 of glycinin. The effect of the recessive alleles on the increase in BC concentration was greatest for gy1,2 (98 g kg−1), intermediate for gy5 (44 g kg−1), and least for gy3 (18 g kg−1). There were significant differences in mean protein and oil concentration, grain yield, and maturity among the eight genotypic classes; however, the differences were not consistent among the populations. It should be possible to develop soybean cultivars with increased BC and decreased glycinin concentration that have protein and oil concentration, grain yield, and maturity similar to cultivars with normal protein composition.
Genetic Diversity of Andean Tuber Crop Species in the in situ Microcenter of Huanuco, Peru
Authors: Malice M. , Bizoux J. P. , Blas R. , Baudoin J. P. 
Published: August 2010

ABSTRACTAndean tuber crop species oca (Oxalis tuberosa Molina), ulluco (Ullucus tuberosus Caldas), and mashua (Tropaeolum tuberosum Ruiz & Pav.) play major roles in Andean communities. These species show high variability but are threatened with genetic erosion. To study the management of genetic resources of neglected vegetatively propagated crop species, we studied genetic diversity and structure of these species in an in situ diversity microcenter (Huanuco, Peru). A sample of 15 varieties of oca, 15 of ulluco, and 26 of mashua was analyzed with the inter simple sequence repeats (ISSR) molecular markers. Mean genetic distances and global genetic diversities were high for the three species, with higher values for mashua than for oca and ulluco. Assignment technique divided both oca and ulluco samples into two genetic clusters; the mashua sample probably belongs to a single genetic cluster. Inter simple sequence repeats (ISSR) technique showed intravarietal genetic variability for most varieties, suggesting an underestimation of the in situ genetic variability. These results are discussed considering how variation in breeding systems and farmers' practice influenced patterns of genetic diversity. Our findings confirm the hypothesis of a considerable amount of variability found in neglected Andean tubers and are essential to deserve adequate conservation strategies and to maintain genetic resources of neglected Andean tuber crop species under a threat of genetic erosion.
Root Characteristics of Two Soybean Cultivars Grown in Fumigated Fields in Iowa
Authors: Murillo‐Williams Adriana , Kaspar Tom C. , Pedersen Palle 
Published: August 2010

ABSTRACTSoybean [Glycine max (L.) Merr.] yield is often limited by root‐infecting pathogens, mainly soybean cyst nematode (SCN; Heterodera glycines Ichinohe). The objective of this experiment was to evaluate differences in root characteristics and yield of NK‐S25J5 (SCN‐susceptible) and IA2068 (SCN‐resistant) soybean cultivars at three locations (De Witt, Nevada, and Whiting) in Iowa, in fumigated vs. nonfumigated soil. A 2‐ha section of a field was fumigated each year with Telone‐35. Root sampling was conducted at 21, 42, and 63 d after emergence (DAE). Initial SCN population densities (Pi) were 4790, 2590, and 825 eggs 100 cm−3 soil for De Witt, Nevada, and Whiting, respectively. Under the conditions of this experiment, there was no evidence of a decrease in Pi caused by fumigation. Fumigation was associated with an increase in final SCN population (Pf), a reduction in yield of NK‐S25J5 by 560 kg ha−1 at De Witt, and at 42 DAE, with an increase in root length density (RLD), and root surface area (RSA). The highest yields were obtained at Whiting, the location where the greatest Pf/Pi was observed for NK‐S25J5. Average yields for IA2068 and NK‐S25J5 were 4745 kg ha−1 and 3665 kg ha−1, respectively. We concluded that greater RLD could be the result of complex modifications of the environment where roots grow, mainly microbial populations, including SCN. Stress caused by SCN was associated with a decrease in yield in the susceptible cultivar.
Soybean Reproductive Sink Size and Short‐term Reductions in Photosynthesis during Flowering and Pod Set
Authors: Egli D. B. 
Published: August 2010

ABSTRACTThe number of pods and seeds produced by soybean [Glycine max (L.) Merr.] is related to canopy photosynthesis during flowering. The effect of low photosynthesis during only a portion of flowering (growth stage R1 to R5), however, is not well defined. Two field experiments were conducted at Lexington, KY (38°N), with seeds sown in mid‐May in 0.76‐m rows (20 seeds m−1 of row) and all plots irrigated as needed. In 2005/2006, plants (cultivars Pennyrile and Ripley) were shaded (60% in 2005 and 80% in 2006) for 4‐ to 9‐d periods just before or just after peak pod production. These treatments had almost no effect on seed number (significant reduction in only one of eight comparisons). In a second experiment (cv. Pennyrile, 2007/2008), shade cloth (60%) was placed over plants at growth stage R1.6 and removed at 7‐d intervals. The first 7 d of shade did not affect seed number, but 14 d of shade ending at roughly growth stage R3.0 reduced seed number by 16% and longer periods caused proportionally larger reductions. When shade cloth (80%) was put in place at 7‐d intervals (starting at R3.4) and left in place until maturity, seed number was reduced until the last treatment (put in place 4–7 d after the beginning of growth stage R6). Seed number was tolerant of short periods (4–9 d) of low assimilate supply during flowering, but could not recover from longer periods of shade (≥14 d), even when they occurred relatively early in the flowering period.
A New PCR‐Based Linkage Map in Pearl Millet
Authors: Pedraza‐Garcia F. , Specht J. E. , Dweikat I. 
Published: August 2010

ABSTRACTPearl millet [Pennisetum glaucum (L.) R. Br.] is a multipurpose cereal grown for grain, stover, and green fodder. Relative to other cereal species, it ranks sixth in annual world production. Use of molecular marker technology for pearl millet genetic improvement has been limited because of an insufficiently developed linkage map. The majority of the pearl millet molecular markers (RFLP and SSR) mapped to date are clustered around the seven pearl millet chromosome centromeres, and only a few marker loci are mapped to more distal regions. There is a need for more evenly distributed markers throughout the linkage map and greater marker coverage of the gaps in earlier established maps. The objective of this research was to develop a PCR‐based molecular marker linkage map for pearl millet on the basis of a recombinant inbred line (RIL) population resulting from a cross between Tift 23DB and PI 536400. This mapping effort involved 152 RILs and 196 PCR‐based DNA markers (66 SRAPs, 63 RAPDs, 27 ISSRs, 31 pearl millet, 6 sorghum, and 3 maize SSRs). The average genetic distance between markers was 9.2 cM, varying from 0 to 25.6 cM. The number of markers in each linkage group (LG) ranged from 6 to 35. The resulting map consisted of nine linkage groups that spanned about 1796 cM. The majority of the markers used in this study to construct the genetic linkage map were randomly distributed in each LG, which makes it useful in pearl millet mapping and breeding.
Effect of Maturity on Seed Sugars as Measured on Near‐Isogenic Soybean (Glycine max) Lines
Authors: Bellaloui N. , Smith J. R. , Gillen A. M. , Ray J. D. 
Published: August 2010

ABSTRACTThe objective of this study was to investigate the effect of maturity and field temperature on the concentration of sucrose, raffinose, and stachyose in soybean seed in two sets of near‐isogenic lines of Clark and Harosoy. The maturity of each line within each set varied, but all lines from each set shared a common genotypic background. The results showed that in the Clark isoline set, maturity had a negative linear relationship (sugars decreased as days to maturity increased) with the concentration of sucrose (r2= 0.83 in 2004;r2= 0.94 in 2005), stachyose (r2= 0.51 in 2004;r2= 0.51 in 2005), and combined sugars (sucrose+raffinose+stachyose) (r2= 0.83 in 2004;r2= 0.91 in 2005). In the Harosoy set, there were significant negative relationships between maturity and sugars only in 2005 for sucrose, stachyose, and combined sugars. In the Clark set, temperature had a significant positive relationship with sugars in 2004 (sugars increased as temperature increased), but significant negative relationship in 2005. In the Harosoy set, there was a significant negative relationship between field temperature and sugars only in 2005. The contribution of maturity to the total variation in sugars was significantly higher than temperature. It was concluded that the effect of genotypic background and maturity genes on sugar concentration depended on the type of sugar.