bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of Temperature and Pressure Fall-Off during Shut-In and Slow-Down for SAGD Wells with Top Water
Authors: Wang Yong , Ferrise Alison , Huang Yinghui
Published: February 2018

In in-situ oil sands operations using Steam Assisted Gravity Drainage (SAGD), understanding the temperature and pressure responses during periods of shut-in and slow-down is crucial for effective steam chamber management. The corresponding operating strategy should be based on the temperature and pressure performance.

At Nexen’s Long Lake in-situ project, there are a number of pads with extensive top water in contact with the target bitumen interval. Along with the rest of the wells in operation at Long Lake, these SAGD wells have experienced several periods of shut-in and slow-down due to maintenance operations and other surface constraints. Surface and downhole sensors and other real-time monitoring technologies provide opportunities to monitor temperature and pressure during these time periods, which help to better understand the impact of surface activities on steam chamber development, particularly in areas with extensive top water present.

This paper presents the temperature and pressure responses over time at different elevations within the reservoir. It compares temperature and pressure responses for the wells with top water and without top water and 4D seismic is also integrated to analyze the causes for the different temperature and pressure responses. Review of the data shows that shut-in has a more significant impact on temperature and pressure in the steam chamber than slow-down. Wells with top water experience severe temperature drops while slow-down wells do not. After long periods of shut-in, areas with thicker top water may take additional time to heat up and reach steam conditions again, resulting in higher steam injection requirements. The collected data suggests that continuous steam injection is crucial to maintain steam chamber with top water.
Solvent Process for Reservoirs with Top Water
Authors: Sood Arun , Gupta Subodh
Published: February 2018

SAGD is an energy and emissions intensive process for bitumen recovery. The situation is worse for reservoirs with lean zones. Industry is looking for ways to make these projects more environmentally friendly and economic by reducing energy intensity and emissions. Previously we have shown that for reservoirs with top water, SAGD is a viable option. Active de-watering of the lean zone can be accomplished using fence wells and air injection, though some water would remain. A new process is presented in which vaporized solvent is used in such a way that it helps keep water ingression into the drainage chamber at bay.

The process is initiated as conventional SAGD. Once steam chamber breaches the de-watered lean zone, one of the previously drilled wells for de-watering is converted to solvent injection while steam injection is ceased. Solvent is injected as vapor at such a rate that it forms a gas blanket over the steam chamber and condenses further away due to cooler temperature in the lean zone. The combined effect of solvent injection pressure and an oil bank formedat the edges of the solvent blanket keep the water at bay. Within core of the vapor chamber, solvent vapor makes contact with cold bitumen, dissolves in the oleic phase and reduces its viscosity. The mobilized oil moves down to the producing well by gravity drainage.

Simulation results show that using propane as the solvent, energy consumption of the process will be reduced by 80% as compared to SAGD (which is still being optimized via simulations), while the average production rate is doubled. Past the SAGD phase, since no steam is injected and the condensed solvent bank is effective in blocking the lean zone water, produced water to oil ratio is very low. Once economic recovery is achieved, propane retained in the reservoir can be recovered by a variety of ways that are discussed in the paper.

The process described above can reduce the capital cost of a green field project by minimizing the water handling facility and significantly reduce the carbon footprint.
Measurement of Non-Equilibrium Solvent Release from Heavy Oil during Pressure Depletion
Authors: Bryan J. , Butron J. , Nickel E. , Kantzas A.
Published: February 2018

Cyclic solvent injection (CSI) is a promising technology for enhanced production of heavy oil in post-CHOPS (Cold Heavy Oil Production with Sand) fields. The first stage of a CSI cycle involves the injection of solvent vapour, which re-energizes the reservoir and dissolves into oil, reducing its viscosity. The second stage of a CSI cycle involves dropping the pressure to flow the solvent-diluted oil back to the well. This is the solvent analog to cyclic steam stimulation (CSS). A key difference between solvent and steam is that the heat from steam stays in the oil even during production, while in solvent-diluted oil, if solvent comes out of solution as pressure drops, oil viscosity will increase again and one of the main benefits of the solvent will be lost. Solvent selection in CSI needs to consider which solvents have non-equilibrium properties, specifically delayed release during pressure depletion.

This study presents a set of low field nuclear magnetic resonance (NMR) tests that were run on a 3,370 mPa·s viscosity heavy oil and several solvents: methane-propane and methane-CO2. NMR measures the relaxation rate of protons in the presence of magnetic fields. When fluid viscosity decreases, the fluid signal relaxes more slowly. A properly calibrated NMR model can be used to measure the viscosity of the liquid phase in a solvent-oil mixture as pressure drops and gas leaves solution. This approach does not require flow, and can also be used to measure the in-situ viscosity of oil in the sand.

Tests were run using methane-CO2 solvents with varying CO2 concentration to study the impact of live oil viscosity on the rate of solvent release. For lower initial live oil viscosity, the solvent is able to more quickly leave solution from the oil. Additional tests run using a methane-propane solvent demonstrate the impact of varying solvent type for the same initial solution viscosity. Both CO2 and propane show significant non-equilibrium solvent release during depletion.

Measurements of non-equilibrium solvent release from oil are an important piece in the understanding and modeling of heavy oil CSI. Equilibrium PVT data shows how different solvents can affect heavy oil systems, but the non-equilibrium solvent release is crucial for these solvents to work as recovery agents in the field. The results presented in this study provide useful data for CO2 and propane as potential CSI solvents, and help in the understanding of the role of viscosity vs. solvent type in the diluted oil response.
Effects of Rock Mechanical Properties and Deformational Behavior on Caprock Integrity in Thermal Operations
Authors: Li Qiuguo , Rivero Jose
Published: February 2018

As a critical input in determining the maximum steam injection pressure, caprock integrity assessment in thermal operations has become increasingly important because of the potential severe consequences of a caprock integrity breach on the environment, safety and project economics. Because of the complex thermo-poro-mechanical coupling of the thermal stimulation process, numerical simulation is required in evaluating caprock integrity.

Thermal stimulation of heavy oil reservoirs significantly alters the pore pressure and in-situ stresses not only in the reservoir, but also in the caprock. Rock mechanical properties also change with temperature, pore pressure, stresses and rock deformation. Accurate characterization of reservoir and caprock mechanical properties and constitutive behavior is critically important in caprock integrity analysis. Through geomechanical and fluid flow coupled simulation of a steam-assisted gravity drainage (SAGD) case using commercially available reservoir simulator and finite element geomechanical simulator, this paper discusses the physical processes that occur in thermal operations, including stress and strain change, rock volume change, and rock failure, in both the reservoir and the caprock. The effects of rock elastic and strength properties, constitutive model, coefficient of thermal expansion, thermally induced pore pressure, and steam injection pressure on reservoir deformation and caprock integrity will be explained through simulation cases.
Lessons Learned from Extending Run Life for Hundreds of ESPs in a Heavy Oil Environment
Authors: Mogollon M. , Arguelles A. , Rodriguez A. , Anaya O. , Miranda S. , Velasquez E. , Villalobos J.
Published: February 2018

Electric submersible pump (ESP) applications with heavy oil pose substantial technical challenges: decreased pump head capacity, increased power requirements, and poor cooling capacity. This paper shares experiences, lessons learned, equipment standardization exercises, and improvements performed in a field with heavy oil (13º API to 15ºAPI) to extend mean time between failures (MTBF) in more than 3,000 days in a high ESP population with an average of 500 wells. To achieve production goals and extend ESP run life, the project tracks five elements of the ESP life cycle: design, optimization, failure analysis, monitoring, and equipment standardization.

As the field evolved, ESPs faced the challenges such as: increased production with increasing water cuts to higher flow rates in horizontal completions with high dogleg severity. Chronological performance of pump mean time between failure is shown before and after improvements. The ESP lifecycle is used as the basis to analyze several factors that caused either total system failure or inability to meet production expectations. This paper explains the implications of each factor and how they affect ESP components, through case studies of representative or repetitive failures and examples of how they were remediating without incurring the expense of oversizing the ESP equipment or completion.

This paper shares lessons learned in a five-year, dynamic heavy oil project and includes practical tools to improve ESP run life and optimize well production, which are applicable across the industry and around the world.
On Temperature Fall-Off Interpretation in Circulation Phase of Steam-Assisted Gravity Drainage Process
Authors: Irani Mazda , Ghannadi Sahar
Published: February 2018

Steam-assisted gravity drainage (SAGD) is the method of choice to extract bitumen from Athabasca oil sand reservoirs in Western Canada. Bitumen at reservoir condition is immobile due to high viscosity and its saturation is typically large that limits the injectivity of a steam at in-situ condition. In a current industry practice, steam is circulated within injection and production wells. In theory wells, should be converted to SAGD production mode once bitumen at interval is mobile and communication is established between the injector and the producer. Operators try to use temperature fall-off data to predict successful conversion time. Although the bitumen heating sounds simple approach recently three wells fails after steam injection due to steam break-through or sand production. And they are periodically returned to circulation to ramp up production rates and heal the hot spots. Most such failures are associated with early conversion to full SAGD. This paper presents a method to describe physics based initial steam injection timing and describes different Suncor assets viscosity variation with temperature and a proper interval temperature for initiation of steam injection in SAGD process. In this study an analytical tool is developed using time-of-flight (ToF) concept to match the temperature fall-off data. The tool is used to discuss successful and failed cases in Suncor McKay River asset.
Dimethylether-A Promising Solvent for ES-SAGD
Authors: Haddadnia Ali , Zirrahi Mohsen , Hassanzadeh Hassan , Abedi Jalal
Published: February 2018

Co-injection of solvent with steam is one of the promising methods to recover bitumen. The major operational cost for these projects is related to steam generation, water treatment and solvent. Propane and butane have shown desirable performance as solvent. In this work, we introduce dimethyether (DME) as an alternative solvent because of its lower cost compared to propane and butane.

We evaluate the capability of DME as a solvent for bitumen recovery processes. To investigate the performance of solvents, a series of experiments were conducted using a 2D sand-pack saturated with Athabasca bitumen. In these experiments, co-injection of steam with DME was compared with steam and steam/butane injections. The steam injection was conducted at 1 MPa and solvent concentration of 5 vol.% was tested in solvent/steam co-injection experiments. The cumulative bitumen production and bitumen production rate for each scenario were measured and compared with SAGD.

Experimental results revealed that using butane and DME as the additives to steam will improve the bitumen recovery. DME showed a performance close to butane. Since the cost of DME is lower than butane, it can be expected that production cost with DME injection is lower than butane. Considering that vapour pressure and density of DME are close to LPG products, its handling and transportation is as easy as LPG. Moreover, availability of DME is another advantage compared to butane. DME can be produced from natural gas or from renewable sources such as waste, wood, and agricultural products using well-established processes. A mobile production unit can be used to convert the produced solution gas to DME, which can reduce the methane emission and the costs of solvent injection.
Factors Affecting Electromagnetic Wave Penetration in Heavy Oil Reservoirs
Authors: Morte M. , Bloom E. , Huff G. , Dean J. , Hascakir B.
Published: February 2018

Electromagnetic waves as a viable means of introducing heat energy to reservoirs to allow for transmission of heavy or extra-heavy oil have been gaining prominence and notoriety in recent years due to its applicability to a wide variety of reservoirs. However, how reservoir properties affect the electromagnetic wave penetration is not well defined. This study investigates the impact of different reservoir rock and fluid combinations on the electromagnetic wave penetration and also introduces the dependency of dielectric properties on pressure. Several different reservoir rock samples (quartz rich, carbonate rich) with varying lithology and porosity were used in this study. The contribution of the fluid type was investigated by saturating the cores with water as well as measuring the responses on dry cores as a control. Air and water saturated rock samples were irradiated electromagnetically at varying frequencies (200 MHz to 6 GHz) under pressure. Frequency dependent dielectric properties were measured for each sample utilizing a coaxial dielectric probe and a vector network analyzer. Dielectric constant (ε′), loss index (ε″), and loss tangent of test mediums were utilized to generate the penetration depth of each sample as a function of frequency. The loss index and dielectric constant comprise the complex permittivity which is the foundation for microwave absorbance and penetration depth. Penetration depth is highly frequency dependent and exhibits an exponential decay where as the wave travels further into the sample more energy is gradually absorbed by the material and thus the energy content of the wave continually diminishes. With lower frequencies, higher penetration depth was obtained for all samples where less energy has been dissipated and absorbed by the formation. The utilization of both water and air represent both a very effective absorber of microwaves as well as a material transparent to microwaves respectively. Therefore, the dry cores (air saturated) realized greater penetration depths as less attenuation occurred due to the transparent nature of the saturating fluid. The quartz rich sandstone achieved lower penetration depths than the limestone core utilized which is indicative of greater capability of the sandstone samples to absorb microwave energy. Reservoir properties will affect the dielectric response of the material and so it becomes necessary to account for the presence of pressure due to overburden while taking laboratory measurements. The pressurized samples for both the sandstones were found to cause disparity between the control experiments when saturated with water. Introducing pressure of the water saturated sandstone samples effectively lowers the loss tangent resulting in a decreased capability to absorb microwave energy.
Three Approaches to Predicting ESP Pump Failures During SAGD Operations
Authors: Fedenczuk Leon , Graham John , Pehlke Trent
Published: February 2018

This paper presents a novel approach to a time scale discretization when predicting ESP pump failures at different scales. This study proves that models can be used to formalize failure predictions, prevention, and lead to optimizing the ESP's replacement and/or maintenance. The target parameters reflected two different time scale ranges. In the first approach ‘Time to Failure’ and its corresponding ‘Active Time to Failure’ were predicted. The second case excluded time periods when a well was off-line for other reasons than failure. These two targets (modeling parameters) represented low frequency events and were developed using geological or/and well geometry parameters. The Total Time to Failure model (Production Period model) based on a combined trajectory and geology data set showed acceptable and stable performance. A corresponding model with wellhead parameters summarized across each production period was introduced to complement the large scale analysis.

A second group of models of higher resolution was designed to detect failures in real time. In these cases estimations for the probability of a failure at a specific time using the most recent wellhead data while excluding well's non-active time periods related to workovers and other non-productive time periods.

These models used pre-processed wellhead data from a few selected wells and pads. Well data required pooling large amounts of data and developing a parameter summarization in time periods based on uninterrupted Motor Current Time Periods. These discrete time periods represented events with or without a failure depending on a reason for the current value to be zero. The probability of a pump failure was estimated using two approaches. In the first approach only the last two ‘periods’ that corresponded to non-failure and failure periods respectively were used. The second approach involved all non-failure periods leading to each corresponding failure period. The first approach overestimated the failures while the second approach overestimated the non-failure events.

Initial probability models predicted events with a relatively high success rate. However, more data and additional data transformations are required to verify the practicality of our approach. More refined sub-period estimates in each Current Time Periods may help in developing improved models.
Christina Lake Early Rise Rate Solvent Aided Process Pilot
Authors: Chen Sam , Seib Brent , Ben-Zvi Amos , Robinson Travis
Published: February 2018

Solvent Aided Process (SAP) combines benefit of using steam with solvents and has the potential to substantially improve SAGD performance with lower energy intensity and impact on the environment. Cenovus has been developing a SAP since 1996 and has conducted a few successful pilots (Senlac 2002, Christina Lake A0101 2004-2005, Christina Lake A0202 2009-2016). Cenovus has planned to implement a SAP in the Narrows Lake development when that project is sanctioned.

The general practice for SAP is to co-inject solvent with steam after the SAGD peak rate is reached as steam is most effective for the vertical growth of steam chamber. However, by injecting solvent during the rise rate phase, there could be a large facility saving by not requiring an additional solvent line to each wellhead. Rather, solvent can be added to the steam header immediately after steam leaves the steam generation plant and distributed to all wells, regardless of their vintage. To de-risk the addition of solvent at the steam header, Cenovus implemented an early rise rate phase SAP pilot at Christina Lake A0201 well pair. The objective of this field pilot was to investigate the effects of butane injection during the SAGD early rise rate phase.

This paper describes the implementation and results of the Christina Lake A0201 early rise rate SAP pilot. Presented in this paper are the results of this field test showing that no adverse effects on SAGD performance were observed when injecting solvent during the rise rate phase. This paper also shows the history match of field production data using CMG CMOST simulation.

The findings of this investigation add to the knowledge base of information related to the optimal solvent injection timing in a SAP process. Insights into performing SAP history matches are also presented based on the simulation study that was undertaken.
Phase Behaviour and Viscosity of Bitumen-CO2/Light Hydrocarbon Mixtures at Elevated Temperatures: A Cold Lake Case Study
Authors: Eghbali Sara , Dehghanpour Hassan , Dragani Jarrett , Zhang Xin
Published: February 2018

Co-injection of CO2 or light hydrocarbons with steam in the SAGD process may improve SAGD efficiency and lead to lower greenhouse gas emissions through reduced Steam Oil Ratios (SORs). Various additives are postulated to have differing effects on bitumen recovery, depending on the nature of the reservoir, the operating conditions, and the API gravity of the oil. A PVT study was conducted to investigate the phase behaviour of CO2-, C3-, and C4-bitumen systems at varying concentrations, representing the edge of a SAP steam chamber with the expected temperature range of 70°C to 160°C.

A produced and dewatered bitumen sample was collected from the Cenovus Osprey Pilot in the Cold Lake oil sands region and characterized. Constant Composition Expansion (CCE) experiments were conducted on solvent-bitumen systems in the temperature range of 70°C to 160°C. Filtration tests were also conducted at high temperature and reservoir pressure to investigate the effect of solvent type and concentration on asphaltene precipitation. A Peng-Robinson Equation of State (PR-EOS) model was calibrated to measured data for CO2-, C3-, and C4-bitumen systems. Viscosity of the bitumen saturated with CO2, C3, and C4 was measured with an electromagnetic-based viscometer elevated temperatures. Phase equilibrium calculations were performed using the calibrated EOS to predict the solubility of the solvents in bitumen. A correlation was fitted to the measured viscosity data to predict the liquid phase viscosity as a function of solvent solubility and temperature for each solvent.

From the CCE tests, two equilibrium phases (i.e., liquid and vapour) were observed for the C3- and CO2-bitumen systems. Three equilibrium phases were observed for the C4-bitumen system at high C4 concentrations. These three phases include a bitumen-rich heavy oil phase, a solvent-rich lighter oil phase, and a vapour phase. Due to the extracting/condensing mechanism and asphaltene precipitation, the bitumen-rich phase formed in C3-bitumen system was lighter than the one in C4-bitumen system. Filtration tests showed more asphaltene precipitation by C3 and C4 dissolution than CO2. Moreover, C3 has more potential for asphaltene precipitation than C4.

Viscosity measurements showed that dissolution of C3 and C4 in bitumen resulted in greater viscosity reduction than CO2 dissolution. This difference was more pronounced at lower temperatures. The highest C4 solubility in bitumen and C4 potential for forming a C4-rich liquid phase showed stronger condensing and extracting effect of C4 than C3 and CO2 in solvent-bitumen interactions. Moreover, C4 lead to more bitumen swelling than C3 and CO2. EOS predictions and viscosity measurements indicated that increasing the solvent concentration in a solvent-bitumen system beyond a defined Threshold Solvent Concentration (TSC) has an insignificant effect on solvent solubility and bitumen viscosity reduction.
Sand Control Testing for Steam Injection Wells
Authors: Fattahpour V. , Mahmoudi M. , Roostaei M. , Wang C. , Kotb O. , Nouri A. , Sutton C. , Fermaniuk B.
Published: February 2018

Injector wells in thermal field developments in Western Canada are usually completed by slotted liners. The purpose of liner installation is preventing sand production after a shut-in, keeping a stable wellbore, and providing an appropriate steam distribution. The objective of this paper is to quantify the role of slot width and slot density on the sanding performance of the liner in cycles of injection and shut-in in a SAGD injection well, through a series of laboratory sand control tests.

A large-scale sand retention testing facility was developed and employed to conduct a series of tests on slotted liner coupons with different slot widths and densities. These tests were tailored to simulate steam injection and backflow during the shut-in. Three representative particle size distributions for the McMurray Formation were used in this study ranging from coarse to fine sand. The experimental set-up allows to measure the amount of produced sand.

Since the produced sand in steam injection wells is not usually cleaned out, the acceptable threshold for sand production in the injector should be more conservative than the same for producer wells. Testing results indicate that the sand control performance of the liner is governed by the slot width and density, and formation particle size distribution. Results indicate a negligible amount of produced sand with gas backflow for a properly designed liner even at very high gas velocities.

Historically, there has been little attention to the sand control design for injector wells. This work highlights the significance of slot density and slot width in the sand control performance for steam injection wells. The paper provides the basis for the proper design of an effective sand control in SAGD injectors.
Cold Solvent Process For Heavy Oil Recovery
Authors: Sood Arun , Gupta Subodh
Published: February 2018

A solvent process for heavy oil recovery is described in which an infill injection well is used to inject a cold solvent into neighboring steam chambers once they merge. Simulation results are presented summarizing acceleration in oil recovery and the beneficial impact on energy consumption.

Approximately 60% of injected energy in SAGD process is retained in the reservoir. If a cold solvent is injected into a SAGD formation, it will use the stored energy to vaporize and spread within the steam chamber, while at the same time effectively cooling it. An infill injection well is drilled near the top of the rich pay zone and half way between two neighboring SAGD well pairs. Once the steam chambers merge, cold solvent is injected targeting the outer peripheries of the steam chamber. A small amount of non-condensable gas can also be added to help with pressure maintenance. Cooling of steam chamber enhances solubility of solvent in the bitumen phase and accelerates recovery. Once a secondary peak oil rate is observed due to the cold solvent, proportion of non-condensable gas to solvent in the injected fluid is steadily increased and eventually steam injection is completely ceased and the process switches to blow down phase with 100% non-condensable gas injection.

Simulation results show that injection of liquid propane and traces of non-condensable gas through the infill injection well provides pressure support and immediately reduces the amount of steam injection required through the primary SAGD injection well by 40-60%. This is followed by a steady increase in oil production rate aided by the viscosity reduction due to propane solubility. A secondary oil production rate peak, comparable to the original peak observed with steam, is achieved. A variation of this process was also simulated for mature SAGD formations, where cold propane injection is accompanied by total steam injection cessation, showing advantageous results.

Cold Solvent Process separates out injection of solvent from steam resulting in a much simpler facility design. No additional energy is used to vaporize the solvent at the wellhead. Unlike steam/solvent co-injection processes, solvent is delivered to the cold bitumen interface directly and extracts useful energy from the residual heat in the rock matrix.
Organic Alkali as a Steam Additive for Improved SAGD: Experimental Study of Emulsion Phase Behavior and Viscosity
Authors: Baek Kwang Hoon , Argüelles-Vivas Francisco J. , Okuno Ryosuke , Sheng Kai , Sharma Himanshu , Weerasooriya Upali P.
Published: February 2018

Water is the most dominant component in steam-based oil recovery methods, such as steam-assisted gravity drainage (SAGD). The central question that motivated this research is whether in-situ bitumen transport in SAGD can be substantially enhanced by generating oil-in-water (o/w) emulsion, in which the water-continuous phase acts as an effective bitumen carrier. As part of the initial stage of the research project, the main objective of this paper is to present the ability of organic alkali to form oil-in-water (o/w) emulsions that are substantially less viscous than the original bitumen.

Experimental studies were conducted for emulsion phase behavior and viscosity for mixtures of Athabasca bitumen, organic alkali, and NaCl brine. Experimental variables included brine salinity, alkali concentration, water-to-oil (WOR) ratio, temperature, and sample-aging time.

The phase behavior study indicated that conditions conducive to o/w emulsions are low alkali concentrations at salinities below 1,000 ppm. At a WOR of 7:3, a single phase of o/w emulsion was observed for 0.5, 1.0, 2.0 and 5.0 wt% alkali with no NaCl, and 0.5 wt% alkali at a salinity of 1,000 ppm at 373 K. At lower temperatures, 323 K and 298 K, flocculation of emulsions in these samples resulted in separation between the bitumen-rich and water-rich o/w emulsions. However, essentially all bitumen content was measured from the bitumen-rich o/w emulsion. The oil contents in these emulsions were more than 70 vol.% at 298 K and 57 vol.% at 323 K. Viscosities of these o/w emulsions ranged between 85 cp and 115 cp at 1.0 s−1, and between 31 cp and 34 cp at 10.0 s−1 at 323 K. At 298 K, they ranged between 105 cp and 250 cp at 1.0 s−1 and between 48 cp and 74 cp at 10.0 s−1. Results in this research show that, in comparison with the original bitumen, bitumen-rich o/w emulsions were 3 to 4 orders of magnitude less viscous at 298 K, and 2 orders of magnitude less viscous at 323 K.
Engineering Prediction of Axial Wellbore Shear Failure Caused by Reservoir Uplift and Subsidence
Authors: Frash Luke P. , Carey J. W.
Published: February 2018

Injection and production can cause significant regional uplift or settlement. We analytically evaluate the potential for cement-annulus failure in response to injection-induced deformation in a coupled casing/cement/rock poromechanical vertical-well system. Deformation is calculated with respect to the initial near-wellbore stress state, occurring immediately after cement curing. Tensile-failure and shear-failure lengths along this well are predicted using a stress-development-length method. The analytical model is verified by Abaqus modeling. A sensitivity analysis identifies critical engineering-well-design parameters for ensuring wellbore-annulus integrity.
Characterization of ‘Castellana’ Virgin Olive Oils with Regard to Olive Ripening
Authors: Mena Carmen , González Alejandra Z. , Olivero-David Raúl , Pérez-Jiménez María Ángeles
Published: February 2018

The production of high-quality virgin olive oil from traditional olive (Olea europaea L.) varieties with peculiar and differential characteristics is of great interest for the olive oil market. ‘Castellana’ is an autochthonous variety mainly located in the center of Spain. The aims of this study were 1) the characterization of ‘Castellana’ virgin olive oils and 2) the evaluation of the influence of fruit ripening degree on the oil quality to establish an optimum harvest time for ‘Castellana’ olives. A wide range of physicochemical and sensorial quality parameters were assayed in oils produced at four harvest times during three crop seasons. ‘Castellana’ oils could be classified into the extra virgin category at all ripening degrees studied. This variety provides well-balanced oils from the sensorial point of view with an optimum chemical composition. Nevertheless, fruit maturation had a strong effect in various quality parameters, especially total phenol content, total tocopherol content, sensorial quality, and to a lesser extent in fatty acid composition. Loss of antioxidants and decrease in sensorial quality take place during olive ripening, reducing the nutritional, sensorial, and commercial quality of virgin olives oils as the harvest is delayed. Results suggest that the production of optimal extra virgin olive oil requires that ‘Castellana’ olives should be harvested from the middle of November to the middle of December, coinciding with a ripening index between 3.1 and 4.1. These results are of great importance to the olive oil industry for improving the quality of virgin olive oils produced from ‘Castellana’.
Response of Japanese Privet to Plastic Mulch Applied over Nonspaced Containers
Authors: Steed Shawn T. , Bechtloff Allison , Koeser Andrew , Yeager Tom
Published: February 2018

Mulches have many positive benefits for the production of plants, ranging from weed suppression to water conservation. In this study, a novel method of using plastic film mulch for container-grown plants was evaluated. Plots of 25 japanese privet (Ligustrum japonicum) in #1 (2.5 qt) nonspaced containers were wrapped with 1.25-mil white or black plastic mulch over the top and sides of containers. Small plants were planted through the plastic and grown for 22 weeks with overhead irrigation. Water application amount was determined by moisture sensors placed in the substrate of each treatment. Plant growth, dry weights (DWs), weed fresh weights, weeding time, substrate electrical conductivity (EC), substrate temperature, total water applied, and mulch costs were determined. Black plastic (BP) and white plastic (WP) mulch reduced water applied by 82% and 91%, respectively, compared with the nontreated control (NT). Nontreated control plants grew faster and had greater DW at the end of the experiment. Mulched containers had fewer weeds and required less labor to remove weeds than the NT treatment. Substrate EC level was greater in BP and WP treatments than for the NT after 20 weeks, and plastic mulch did not result in different substrate temperatures. Plastic mulch added $4.94/1000 containers ($2.24 input cost and $2.70 removal cost) to production costs, not including disposal costs. This novel method of mulching nonspaced plants reduced irrigation water, herbicide applications, and weeding labor, but probably added 2–3 weeks to finish time.
Blueberry Producers’ Attitudes toward Harvest Mechanization for Fresh Market
Authors: Gallardo R. Karina , Stafne Eric T. , DeVetter Lisa Wasko , Zhang Qi , Li Charlie , Takeda Fumiomi , Williamson Jeffrey , Yang Wei Qiang , Cline William O. , Beaudry Randy , Allen Renee
Published: February 2018

The availability and cost of agricultural labor is constraining the specialty crop industry throughout the United States. Most soft fruits destined for the fresh market are fragile and are usually hand harvested to maintain optimal quality and postharvest longevity. However, because of labor shortages, machine harvest options are being explored out of necessity. A survey on machine harvest of blueberries (Vaccinium sp.) for fresh market was conducted in 2015 and 2016 in seven U.S. states and one Canadian province. Survey respondents totaled 223 blueberry producers of various production sizes and scope. A majority (61%) indicated that their berries were destined for fresh markets with 33% machine harvested for this purpose. Eighty percent said that they thought fruit quality was the limiting factor for machine-harvested blueberries destined for fresh markets. Many producers had used mechanized harvesters, but their experience varied greatly. Just less than half (47%) used mechanical harvesters for fewer than 5 years. Most respondents indicated that labor was a primary concern, as well as competing markets and weather. New technologies that reduce harvesting constraints, such as improvements to harvest machinery and packing lines, were of interest to most respondents. Forty-five percent stated they would be interested in using a modified harvest-aid platform with handheld shaking devices if it is viable (i.e., fruit quality and picking efficiency is maintained and the practice is cost effective). Overall, the survey showed that blueberry producers have great concerns with labor costs and availability and are open to exploring mechanization as a way to mitigate the need for hand-harvest labor.
Consumer Perceptions of Landscape Plant Production Water Sources and Uses in the Landscape during Perceived and Real Drought
Authors: Knuth Melinda , Behe Bridget K. , Hall Charles R. , Huddleston Patricia , Fernandez R. Thomas
Published: February 2018

Water is becoming scarcer as world population increases and will be allocated among competing uses. Some of that water will go toward sustaining human life, but some will be needed to install and support landscape plants. Thus, future water resource availability may literally change the American landscape. Recent research suggests that consumers’ attitudes and behavior toward potable water supplies have changed in other countries because of greater social awareness and increasingly widespread exposure to drought conditions. We conducted an online survey of 1543 U.S. consumers to assess their perceptions about landscape plants, the water source used to produce them, and plant water needs to become established in the landscape. Using two separate conjoint designs, we assessed their perceptions of both herbaceous and woody perennials. Consumers placed greater relative importance on water source in production over water use in the landscape for both herbaceous and woody perennials included in this study. They preferred (had a higher utility score for) fresh water over recycled water and least preferred a blend of fresh with recycled water for perennials and recycled water used for woody perennial production. In addition, the group that did not perceive a drought but experienced one placed a higher value (higher utility score) on nursery plants grown with fresh water compared with those which were actually not in drought and did not perceive one. Educational and promotional efforts may improve the perception of recycled water to increase the utility of that resource. Promoting the benefits of low water use plants in the landscape may also facilitate plant sales in times of adequate and low water periods.
Sensory Comparison of Ciders Produced from Machine- and Hand-harvested ‘Brown Snout’ Specialty Cider Apples Stored at Ambient Conditions in Northwest Washington
Authors: Alexander Travis Robert , Ross Carolyn F. , Walsh Emily A. , Miles Carol A.
Published: February 2018

Machine harvest of ‘Brown Snout’ specialty cider apple (Malus ×domestica) has been shown to provide yield and juice quality characteristics similar to that of hand harvest. In this 2-year study, the sensory perception (color, aroma, flavor, mouthfeel, taste, and aftertaste) of ciders produced from machine-harvested and hand-harvested fruit that were ambient stored (56 °F) 0–4 weeks postharvest were compared using a trained panel and electronic tongue (e-tongue). For nearly all sensory attributes evaluated, the trained panelists scored the 2014 machine-harvested samples higher than the 2014 hand-harvested samples. Some of the key sensory differences included a darker color, a more astringent and heated mouthfeel, and a more sour taste of the machine-harvested samples than the hand-harvested samples. Trained panelists perceived no differences due to the harvest method among the 2015 samples for any of the sensory attributes evaluated. The e-tongue demonstrated good discrimination (index value = 95) of 2014 samples, but poor discrimination (index value = −0.5) of 2015 samples, mirroring the year-to-year variation experienced by the trained panelists. Overall, the e-tongue demonstrated a response to metallic and sour that was more associated with the machine-harvested samples and a response to sweet and umami that was more associated with the hand-harvested samples. These results demonstrate that cider made from machine-harvested fruit can have a different sensory profile than cider made from hand-harvested fruit. A consumer tasting panel should be conducted next to provide an indication of market response to the differing sensory profiles, qualifying the impact of harvest method. Results also indicate that ambient storage (56 °F) of fruit up to 4 weeks may not impact cider sensory attributes; however, cider apple growers should avoid ambient storage of machine-harvested fruit given the significant yield losses demonstrated in previous studies. Variation in cider quality due to year of harvest was most likely a result of differences in the hand-harvest technique between the 2 years, specifically more fruit bruising in 2014 than in 2015, demonstrating the importance of harvesting fully mature fruit with a standard protocol so as to supply a consistent raw material to cider producers. The e-tongue produced variable results compared with trained panelists and more development is needed before it can be incorporated into cider sensory evaluation protocol.
The Potential Use of Metamitron as a Chemical Fruit-thinning Agent in Mandarin
Authors: Stander Ockert P.J. , Botes Johané , Krogscheepers Cornelius
Published: February 2018

Under conditions of profuse flowering and excessive fruit set, citrus (Citrus sp.) fruit need to be thinned to increase the size of remaining fruit, reduce the intensity of alternate bearing, or both. Metamitron was recently developed as a chemical fruit-thinning agent for apple (Malus ×domestica) and pear (Pyrus communis), and it inhibits photosynthesis and is thought to transiently reduce the carbohydrate pool in fruit trees. Citrus trees are sensitive to carbohydrate stress during and immediately after flowering, but the response of citrus to foliar treatment with a photosynthesis inhibitor, such as metamitron, is unknown. The purpose of this study was to evaluate metamitron for its effects on leaf carbohydrates and its ability to chemically thin citrus fruitlets. Significant fruit-thinning effects were found in all the experiments conducted over two seasons. A 300 mg·L−1 metamitron treatment reduced leaf sugars and leaf total carbohydrates, and consistently reduced the total number of fruit per tree in both seasons in ‘Nadorcott’ mandarin (Citrus reticulata), irrespective of the timing of application. In the second season, a reduction in fruit yield was reported with an increase in metamitron concentration, both in mass and number of fruit per tree. A 150 mg·L−1 metamitron treatment in November had no fruit-thinning effects, and fruit yield was not different from the control. The application of metamitron did not increase the fruit size of ‘Nadorcott’ mandarin and had no direct effect on other fruit quality attributes in either season. Metamitron can be used as a chemical fruit-thinning agent to reduce fruit numbers in ‘Nadorcott’ mandarin, but an increase in fruit size or quality should not be expected.
The integrated approach to teaching programming in secondary school
Authors: Martynyuk Aleksej Anatolevich
Published: February 2018

The article considers an integrated approach to teaching programming with the use of technologies of computer modeling and 3D-graphics, allowing to improve the quality of education. It is shown that this method will allow you to systematize knowledge, improve the level of motivation through the inclusion of relevant technologies, to develop skills of project activities, to strengthen interdisciplinary connections, and promotes professional and personal self-determination of students of secondary school.
Creative thinking as the key to the successful development of the personality of junior schoolchildren
Authors: Lunina Galina Vladimirovna
Published: February 2018

This article discusses different points of view on the problem of creative thinking of the younger students. The result of the development of this kind of thinking is the ability of each student to discover their talents, realize their creative potential. The author shares her experience and writes about the techniques and methods of creative thinking development, talks about solutions to non-standard tasks using an original approach based on finding innovative solutions to difficult problems.
The model of information system supporting Russian international scientific and educational communications with the countries of Latin America
Authors: Bychkova Natalia Aleksandrovna , Eliseeva Natalia Vladimirovna
Published: February 2018

The article presents the concept and principles of creating a system of international scientific and educational cooperation between Russia and Latin America, as a common information space for professional communication and search for partners. This system will become a single information space for universities, scientific organizations, enterprises, venture and investment funds for the exchange of scientific and educational information, promising scientific research, technological solutions and training programs.
Effects of recognition of Jerusalem as the capital of Israel
Authors: Shemeneva Anastasia Valerievna , Soldatova Elizaveta Aleksandrovna
Published: February 2018

The authors note that the status of East Jerusalem, and especially its holy places, remains a key and very controversial issue in the Israeli-Palestinian conflict and the subject of heated debates. According to the Resolution of the UN General Assembly No. 181 of November 29, 1947 known as the “Resolution on the partition of Palestine”, the international community will take control of the future of Jerusalem after the end of the British mandate (May 15, 1948).