bluuebunny/crossref_metadata_2025 huggingface dataset:
Systematic Laboratory and Modelling Study of Kaolinite in Rocks on Formation-Damage-Fines-Migration Non-Equilibrium Effects, Analytical Model
Authors: Russell Thomas , Chequer Larissa , Badalyan Alexander , Behr Aron , Genolet Luis , Kowollik Patrick , Zeinijahromi Abbas , Bedrikovetsky Pavel
Published: January 2018

The main objective of this work is to characterize the formation damage induced by fines migration in reservoir rocks with different kaolinite contents. The problem is particularly important for water production during oil and gas well operations, and for injectivity and sweep during low-salinity waterflooding.

We perform laboratory corefloods using aqueous solutions with different salinities in engineered rocks with different kaolinite content, yielding fines migration and permeability alteration. A novel methodology of preparing artificial sand-packs with a given kaolinite fraction has been established. Sequential injections of aqueous solutions in order of decreasing salinity were performed in five sand-packs with different kaolinite fractions varying from 1 to 10 weight percentage. Severe permeability decline was observed when deionized water was injected into the cores.

A new analytical model that captures the effects of fines release with delay and their re-entrapment by the rock has been developed. The new model allows for explicit expressions for the attached, suspended, and strained particle concentrations, as well as the pressure drop across the core. The analytical model shows good agreement with the laboratory-observed phenomena across a wide range of kaolinite concentrations. The model constants are presented for each of the five cores and lie within typically reported values.

The laboratory protocol and mathematical model allows for reliable prediction of fines-migration related formation-damage during waterflood, EOR, and commingled production of low-salinity water with oil or gas.
Improving Well Productivity of Tight Gas Reservoirs by Using Sodium Silicate in Water-Based Drill-in Fluid
Authors: Jafarov T. , Mahmoud M. , Al-Majed A. , Elkatatny S. , Bageri B.
Published: January 2018

The main objectives of this work are to prevent water blockage problem of wells drilled to tight gas reservoirs by minimizing fluid invasion and to reduce solid invasion with the optimized sodium silicate concentration in actual drill-in fluid and ultimately, improving well productivity by obtaining high return permeability after forming the very thin, impermeable and easily removable filter cake.

Static filtration tests were conducted on 0.25″ tight cores at 300°F under 300 psi ΔP with 250 psi back pressure and 500 psi inlet pressure to collect filtrate volumes. Rheology tests were performed up to 140°F under atmospheric and at 300°F under 300 psi pressure. Rheology experiments were performed for base fluid and with 0.05, 0.075, 0.1 wt%, while filtrations were also performed for 0.5, 1 and 1.5 wt% sodium silicate concentrations. Initial and return permeabilities were measured by injecting 3 wt% KCl through 2″ core sample under constant flow rates after damaging it. CT numbers were obtained before and after damaging 2″ core by doing CT Scan.

Filtrate volume and cake thickness reduced by 53% and 65% with 0.075 wt% (3.5 ml & 0.7 mm), respectively, compared than base fluid (7.4 ml & 2 mm). 0.075 wt% determined as an optimum concentration. Water blockage problem of tight gas wells prevented by minimizing the fluid invasion. Measured initial and return permeabilities of 2″ core remained same as 1.3 mD. This result proved that no solid invasion occurs with 0.075 wt% sodium silicate and in case of 100% filter cake removal, return permeability will be 100%. Forming filter cake with 0.7 mm thickness lets us to claim that it can be completely removed by washing with 15 wt% HCl. Obtained CT numbers confirmed return permeability measurement as well.

Barite flotation recovery and solubility concentration of silica with PH are the two approaches that should be considered together to explain the mechanism of 0.075 wt% sodium silicate. Polymerization effect shows itself for ≤0.075 wt%, while amorphous silica effect occurs for >0.075 wt%. Polymerization effect became the evidence of obtaining 100% return permeability.
Chelate Based Acidizing Fluid Provides HSE Advantages in Successful North Sea Application
Authors: Santos A. Dos , Oliveira E. , Stanitzek T. , Hoq A. , Doghmi A.
Published: January 2018

Matrix stimulation is commonly utilized to increase well productivity and it is a process in which fluid selection plays a key role in treatment success. However, in offshore fields, the acid formulation must not only be effective in damage removal but it also has to meet stricter HSE regulations while safeguarding expensive and complex installations from corrosion impact. In high temperature environments or where sensitive metallurgy is deployed, higher doses of corrosion inhibitors are required as well as additional additives in order to avoid unwanted reactions, further complicating the handling and HSE aspects of such acids.

The environmentally friendly chelate, glutamic acid N,N-diacetic acid GLDA, has been examined as an alternative for acidizing and descaling treatments, demonstrating good field performance in terms of productivity and injectivity increase. All this achieved while providing a safe and convenient system for handling, due its low toxicity, fewer required additives and biodegradability. Numerous laboratory tests have measured and confirmed considerably less corrosion risk, across a wide range of conditions, when compared to conventional formulations based on both HCl and organic acids. Within this paper, the field performance of the GLDA system will be evaluated under even more challenging conditions, endured during the acidizing of an offshore well in the North Sea.

The wellwork programme for the low rate gas producer consisted of performing two new perforation runs, followed by the injection of the GLDA treatment, which was then bullheaded into the formation with a nitrogen assist. The treatment formulation consisted of GLDA diluted in fresh water with trace amounts of surfactant and mutual solvent to aid in the flow-back of the spent acid.

Due to an unexpected power failure on the platform, the treatment remained stagnant in the tubing for some 28 hrs at 300°F. As this was the first GLDA treatment in this field, this situation appropriately raised potential well integrity concerns; as would most certainly have been the case with a conventional HCl acid package. However, once the operation was restarted the acid was successfully bullheaded into the formation and no issues resulted with the low carbon and CRA based metallurgy of the completion even after this extensive unplanned exposure. Additionally the treatment resulted in a significant productivity increase.

These operations and results demonstrated not only the gentle nature of GLDA for integrity considerations; but also an effective cleanout of perforations and near wellbore area as required from a replacement system. The success of the treatment proved the intrinsic value and reduced risk that can be accessed by use of such systems.
Improving Well Injectivity by Surfactant Flushing - A Digital Rock Study
Authors: Bautista J. F. , Xu R. , Fager A. , Crouse B. , Freed D.
Published: January 2018

There are many causes for injection wells to perform poorly; in this paper, we address the effect of residual hydrocarbons near the wellbore, which reduce the rock's effective permeability to brine, thus decreasing well injectivity. Immobile hydrocarbon saturations are found around injection wells when these are drilled above the water-oil contact level, which arises when a producer well is switched to injection, or the formation's underlying aquifer is hard to reach. Furthermore, oil can accumulate around a wellbore when produced brine containing even trace amounts of hydrocarbons is used as the injection fluid. To address this problem, it is possible to flush out hydrocarbons around the wellbore by periodically injecting small amounts of surfactants for short periods. This technique leverages the capillary desaturation behavior of a multi-phase fluid mixture, wherein increasing the capillary number of a rock-fluids system beyond a threshold value will decrease the residual hydrocarbon saturation. The capillary number, which characterizes the ratio of viscous to capillary forces, can be increased by injecting surfactant loaded brine; this reduces the hydrocarbon-brine interfacial tension which reduces the capillary forces, decreases the system's residual hydrocarbon saturation, and increases the brine's effective permeability. To efficiently assess the impact of a surfactant flush, we perform digital rock multi-phase flow simulations on Berea and Fontainebleau sandstones at different capillary numbers. The simulations provide the residual hydrocarbon saturation and the brine's effective permeability as a function of capillary number, which is related to the amount and type of surfactant. These results are then used in a radial wellbore simulation to compute the attainable injection rate for a maximum allowable pressure drop. Since the largest pressure drop occurs very close to the wellbore, the surfactant flush is very effective even though it only affects a few feet from the wellbore. For the specified scenario we observe a potential well performance improvement ranging between 20% and 150%. By using digital methods, this study was performed in about two weeks, at lower cost than Special Core Analysis Laboratory (SCAL) physical testing, and with ideal reproducibilty since the capillary number can be modified without affecting the sample or any other aspect of the test procedure.
Effect of Fracturing Chemicals on Well Productivity: Avoiding Pitfalls in Big Data Analysis
Authors: Khvostichenko Daria , Makarychev-Mikhailov Sergey
Published: January 2018

A statistically rigorous assessment of the effect of fracturing treatment chemical additives on well productivity was performed. The dataset for analysis consisted of over 4,500 slickwater-treated wells in the lower 48 US states. All wells were treated by a single service company within a 5-year period. The analysis focused on two distinct additives, namely, linear guar gels and surfactant-based flowback aids, in slickwater treatments. A method and workflow to quantify the effects of completion parameters on well productivity were developed in this work. The statistical t-test was used to assess the statistical significance of differences in aggregated production metrics between datasets based on the observation that production data were distributed log-normally. The proposed workflow addresses many common issues a reservoir engineer faces during data sourcing, preprocessing, evaluation, and interpretation and further highlights the importance of proper statistical approaches. The analysis results emphasize the benefits of proper job design even in relatively simple slickwater treatments.
Lowering Fresh Water Usage in Hydraulic Fracturing by Stabilizing scCO2 Foam with Polyelectrolyte Complex Nanoparticles Prepared in High Salinity Produced Water
Authors: Hosseini H. , Tsau J. , Peltier E. , Barati R.
Published: January 2018

Polyelectrolyte complex nanoparticle (PECNP) systems compatible with produced water were developed to improve supercritical CO2 (scCO2) foam stability and to reduce fluid loss for fracturing applications. Foam viscosity, stability, fluid loss properties and cleanup of injected liquid through the formation were enhanced by PECNP-surfactant systems prepared in produced water medium. Taking advantage of produced water as energized fluids for fracturing requires enhanced compatibility of gas/liquid mixture. Two produced water recipes of 33,333 and 66,666ppm TDS were used to prepare 1 w/w% surfactant solutions. PECNP was formed as a mixture of positively- and negatively- charged polyelectrolytes. Experimental setup was designed to determine the aqueous foam stability at actual reservoir conditions. Rheological measurement was performed to measure the stability of the bulk foam under shear and to evaluate the foam texture properties. The improved viscosity of different proportions of PECNP-Surfactant (9:1, 8:2, 7:3, and 6:4) in aqueous foam mixtures was observed as compared to surfactant stabilized CO2 foam. The flow consistency index observed in the shear thinning region was also increased from 1184.3 to 2916.4 Pa sn in 33,333ppm and from 1035.7 to 1683.1 Pa snin 66,666ppm brine solutions. The view cell results revealed the high stability and longevity of scCO2 foam employing various proportions of surfactant to nanoparticle as oppose to surfactant generated foam in which the foam height shortened faster. The presented scCO2 generated foam can preserve the foam cellular structure in absence of crude oil. The PECNP-Surfactant system successfully lowered the interfacial tension to up to 74% and 93% for 33,333 and 66,666ppm brine salinity, respectively. Fluid loss was measured to evaluate fluid leak-off from a core when the high flow velocity along the core exists. The fluid loss for both CO2 and water leak-off were also lowered employing PECNP- Surfactant containing foam.
A Large-Scale Sand Retention Test Facility for Evaluation and Selection of Optimal Standalone Sand Screen for Injection Wells in Thermal Operations
Authors: Mahmoudi M. , Fattahpour V. , Wang C. , Kotb O. , Roostaei M. , Nouri A. , Fermaniuk B. , Sauve A. , Sutton C.
Published: January 2018

Sand production is not usually considered a major concern during the injection phase in injection wells. However, well shut-in for service requirements or sudden pump failure, hence the backflow towards the wellbore and potential generation of water hammer pressure pulsing, can lead to massive sand production under favorable conditions. With the aim of sanding prevention, this paper examines the design criteria for standalone screens (SAS) in injection wells using a novel sand control testing facility.

This paper presents a new large-scale sand retention testing (SRT) facility to simulate the effect of pressure pulsation and backflow in injection wells on the sand control performance of SAS. The SRT facility can be used in the selection of the best sand control method for injector wells. It can be also used to provide further understanding on the impact of formation damage on well injectivity decline, as well as study the effect of water hammer pressure pulsation on sand production in injection wells.

Test results show a rapid fall off in the pressure and drastically high backflow rates due to the sudden shut-in. Higher pressure drops are observed to result in a greater backflow volume and a longer backflow period. Results also show that the slot width has a drastic influence on the sanding performance of the screen. Testing observations, for the studied PSD, indicate that the injection well requires narrower slots 1.4 D10 to meet the sand production requirements due to a high fluidization potential in the near-screen zone. Higher flow velocities during the backflow period and the tossing effect caused by the pressure waves increase the sanding potential. The produced sand during the backflow period, is observed to mainly relate to the ratio of the slot width to the mean formation grain size. It is observed that higher effective stresses around the screen work towards stabilizing the sand bridges and reducing the amount of produced sand.

This paper presents a new experimental test facility for the sand control type selection and evaluation for injection wells with the aim of limiting the amount of produced sand and sustaining the wellbore injectivity. The proposed testing facility allows the performance comparison of different sand control devices and designs.
Formation Damage Circumvent in HP-HT due to Pore Pressure Regression
Authors: Shaker Selim S.
Published: January 2018

One of the main causes involved in reservoir formation damages is the excessive mud filtrate during drilling with an overbalanced mud weight. Results show reservoir pressure retreat due to geological structural failure can leads to a large disparity between MW and PP especially in HPHT environment.

This new approach focuses on the geological structural failure that causes the well bore trajectory to cut through different transgressive and regressive pressure envelops. If the mud program, based on the pre-drill pore pressure model, did not account for a pressure retreat, a sizeable lost circulation can take place. Mud fluid invasion to the open borehole wall can decrease permeability, impact logs measurements and potential production. Moreover, thick mud cake causes bore-hole tight spots, excessive torques and pulls. Incorporating the subsurface geological structure features to the seismic driven pre-drilling models can foresee the unexpected mud weight overbalance intervals.

In relative old sediments, such as Oligocene and Miocene in the offshore shelf areas, a substantial mud weight (MW) increase of 2-5 ponds is needed to penetrate the top of geopressure (TOG). The deeper geopressured compartments are usually drilled with MW that sometimes reaches 18 pounds per gallon. Moreover, temperature can range from 300 to 350 degrees Fahrenheit. Formation damages and serious challenges take place where the MW is overbalance juxtaposing a regressive permeable rock sequence. Study the relationship between geopressure compartmentalization and drilling challenges of multiple wells in East – West Cameron, offshore Louisiana sheds light on one of the important causes of formation damages, tight spots, high torque and pulls. Pay zones were partially masked due to deep mud filtrate invasion with frequent use of oil-base to reduce pulls in the tight spots. Sidetracks usually was the ultimate remedy for some of the wells that did not reach their objective TD. The case histories shown in this study illustrate that exploring the depth to the possible regression zones before drilling in conjunction with the pre-drill pore pressure model could have alerted drillers for MW amendment to avoid lost circulation.

The benefit of correlating the bore-hole trajectory to the seismic semblance associated with the geopressure profile is a resourceful method of foreseeing the troublesome intervals. In real time, calibrating the MW derived from the seismic pre-drill model is another deterrent process to avoid utilizing excessive overbalanced MW.
High-Temperature Viscoelastic Surfactant Fluids with Low Scaling Tendency and Based on Seawater, Produced Water, or Brines
Authors: Li Leiming , Liang Feng
Published: January 2018

The viscoelastic surfactant (VES) fluids have been widely used in oilfield operations due to their advantages over polymer-based linear or crosslinked fluids that include low formation damage, good proppant suspending and carrying ability, strong tolerance to low-quality water, to name a few. Most of the conventional VES fluid systems, however, have upper temperature limits at around 250°F, beyond which the fluid performance and stability quickly deteriorate.

In this paper, a new type of VES fluids formulated with seawater, produced water, or brines showed excellent performances at 350°F or higher, while at the same time had low scaling tendency upon mixing with high-TDS formation water downhole. To reduce the chemical cost of the new VES fluids, a number of novel and low-cost additives were successfully identified that significantly increased the fluid viscosity at elevated temperatures, resulting in similar or better fluid performances with reduced dosages of the VES molecules.

The selected VES-enhancing additives strengthened the VES fluids formulated with various sources of water including low-quality water like seawater or produced water at high temperatures up to 350°F or more. In one example, when additive-I was added at the dosage of about 0.8% by weight, the VES fluid viscosity was enhanced by about 35% on average between 300 and 350°F. At 350°F, the viscosity enhancement was about 50% with the same loading of additive-I. The overall cost of the additive-I applied was below 3% that of the baseline VES fluid. In another case, compared with the baseline VES fluid, additive-II at the dosage of about 0.8% by weight raised the fluid viscosity at 350°F to over four times. The cost of the additive-II used in the case was also trivial when compared with that of the baseline fluid. The fluid viscosity could also be enhanced when a number of other selected additives were added to the VES fluids at appropriate dosages. The additive-enhanced VES fluids, in the meantime, caused only minimal damage to the formation, as the regained permeability was about 90%.

The novel VES-enhancing additives might have, through van der Waals forces, simultaneously attached to multiple VES micelles in the fluids, thus strengthening the three-dimensional network of the VES micelles. This way, the overall fluid viscosity could be increased. Further discussions about the enhancing behaviors and mechanisms of the selected additives in the VES fluids formulated with seawater, produced water, or brines, and the laboratory test results will be presented in detail.
Effect of Multi-Stage Hydraulic Fractures on Performance of Naturally Fractured Tight Oil Reservoirs with Bottom-Water
Authors: Prasun Samir , Ghalambor Ali
Published: January 2018

Water coning is a major concern in any oil reservoirs with bottom-water. Stimulation techniques such as multi-stage hydraulic fracturing in a horizontal well can accelerate water coning, but uncertainty prevails over the increased recovery under bottom-water support. This paper studies the effect of hydraulic fracture (HF) design properties combined with the matrix and natural fractures properties in tight reservoirs on water-cut and recovery. Ultimately, the results can be applied in deciding the feasibility and design parameters of multi-stage hydraulic fracturing in these reservoirs.

The paper presents a 3-D Cartesian simulation model, which is run for different fracture half-length, fracture height, HF conductivity, natural fractures permeability and matrix permeability, to represent wide variety of hydraulically fractured reservoir systems. Dual porosity-dual permeability (DPDP) model is used to simulate natural fractures inside water-wet reservoir matrix. In a constant pressure bottom-water reservoirs, where the reservoir pressure remains more or less constant and so there is a minimal change in effective stresses with production time, any effect of these stresses on the variation of fracture conductivity or productivity can be ignored.

Results show that although there is a severe water-cut problem associated with hydraulic fracturing a tight oil reservoir with bottom-water, recovery increase is much higher than that without bottom-water, demonstrating the viability of the project. Based on the simulation results on the sensitivity of HF conductivity on water-cut and recovery, lower HF conductivity with smaller fracture width should be preferred which would further reduce the cost associated with the proppants required. Higher matrix permeability enhances the ultimate recovery, whereas tighter zones brings more water-cut problem. Further, studies showed that HF half-length should not be too low to result in low recovery (at10 years) or should not be too high to give rise to low ultimate recovery. Operators should be concerned about the height of HF, as they should not allow it to propagate beyond the upper oil-zone either to transition-zone or water-zone that can severely mitigate the recovery rate as well as ultimate recovery with severe water-cut problems.

This study which is based on sensitivity analysis, can be used to design the fracture half-length, height, and conductivity in bottom-water-tight reservoirs. The study can provide a boost to operators who are reluctant to hydraulically fracture a bottom-water reservoirs.
Laboratory Investigation of Zinc and Lead Sulphide Inhibition
Authors: Al-Harbi Bader G. , Graham Alexander J. , Sorbie Ken S.
Published: January 2018

The formation of zinc sulphide (ZnS) and/or lead sulphide (PbS) has been a persistent problem, particularly in high temperature high pressure HT/HP fields. ZnS and PbS deposition can pose safety hazards and have serious economic consequences including reduction in well productivity and may require the implementation of an effective scale mitigation and removal strategy. HT/HP fields are prone to critical changes in temperature and pressure and, in addition, they usually have high salinity brines; indeed they are often referred to as HP/HT/HS systems. When these factors (pressue/temperature/salinity) vary together, they tend to trigger the formation of inorganic scales including sulphides. Apart from the role of temperature and salinity in scale formation, these (HT/HS) conditions often negatively impact scale inhibitor performance due to chemical degradation or incompatibility.

The objective of this study was to investigate ZnS and PbS formation (as single or combined scales) and inhibition over a range of parameters including pH, temperature, salinity, time and initial Zn, Pb and H2S concentrations. Polymeric and phosphonate scale inhibitors (SIs) were tested using static scale formation experiments, with samples being analysed by inductively coupled plasma (ICP) analysis, Environmental Scanning Electron Microscopy (ESEM), pH and particle size distribution measurements.

Of the seven scale inhibitors tested, only two demonstrated inhibitory capacity at active concentrations of 100 ppm or below. SI-2, a high-molecular weight polymer, was remarkably effective in preventing both zinc and lead sulphide deposition regardless of the final supernatant pH. SI-3 showed more limited efficacy compared with SI-2 with its highest inhibition being achieved at low pH values.This information is important to consider when designing scale inhibitor treatments; as carbon dioxide liberates from produced water due to decreasing pressureit causes the pH to increase, which may cause a drop in the inhibition efficiency of some scale inhibitors. Increasing the brine salinity had a detrimental impact on the performance of the tested scale inhibitors. Neither SI-2 nor SI-3 were able to prevent PbS deposition by ionic displacement of Zn from ZnS by Pb2+ despite the fact that both scale inhibitors were effective against PbS under the same conditions using the conventional scale inhibition experiments.

The particle size distribution of the partially inhibited ZnS and PbS particulates was found to be dependent on the type and concentration of the scale inhibitor, the final pH and salinity. The difference in particle size could have significant effects on in-line filter blocking tests and produced water quality issues.
An Improved Ball Sealer Model for Well Stimulation
Authors: Tan Xuehao , Weng Xiaowei , Ahmed Tausif Khizar , Bukovac Tomislav , Enkababian Philippe
Published: January 2018

Ball sealers are commonly applied in fracturing and acidizing treatments for diverting treatment fluid to the desired zones by plugging perforations. It has proven that injecting ball sealers is a low-cost and efficient method for diversion. To predict the effectiveness of ball sealers, an improved ball sealer seating model is developed by introducing the maximum seating efficiency and random functions to capture the stochastic nature of ball-sealer plugging. The new model can predict ball sealer performance with different ball densities in vertical, deviated and horizontal wells.

The traditional ball sealer model was originally designed for vertical wells, where ball sealers with different densities have similar behavior. However, for deviated and horizontal wells, the seating of buoyant and dense balls is more complicated. Buoyant balls tend to plug the perforations at the top of wellbore, and dense balls tend to plug the perforations at the bottom of wellbore. Thus, the traditional ball sealer model cannot be applied in these wells. A maximum seating efficiency for each ball is introduced in the new model, which is obtained by correlations based on experimental results. To describe the stochastic nature of ball sealer seating on perforations, a random number is assigned to each ball sealer, and a range is assigned to each perforation based on the ratio between flow rates through the perforations and flow rate in the wellbore.

With the improved model, it can predict seating efficiency of ball sealers for all types of well with buoyant, neutral and dense balls. The results are showing that the seating efficiency of ball sealers predicted by the model can match the experimental results, which validates the model. Based on the simulation results, when ball sealers with mixed densities are pumped into deviated or horizontal wells, the seating efficiency is better than pumping ball sealers with only one density. For vertical wells, the benefit of mixing densities is minimal.
Nanomaterials-Enhanced Hydrocarbon-Based Well Treatment Fluids
Authors: Li Leiming , Ozden Sehmus , Al-Muntasheri Ghaithan A. , Liang Feng
Published: January 2018

The introduction of water-based fracturing fluids to water-sensitive formations may cause formation damages and thereafter lower the production numbers. Due to the advantages such as low formation damage, good proppant suspending and carrying ability, good compatibility with water-sensitive formations, etc., the waterless, hydrocarbon-based fluids are routinely used in fracturing, sand control, coiled tubing cleanout, and other oilfield operations.

To better generate fractures and place proppant, the phosphate esters-based gelled oil fluids have been preferred since they are more robust and cost-effective compared to other types of hydrocarbon-based fluids. Phosphate esters are commonly used with metal crosslinkers such as iron or aluminum compounds to form gelled oil fluids. Since phosphate esters may cause fouling in refinery equipment, the dosage should be reduced to the minimum but without compromising the fluid performance. A number of novel additives have been identified that could maintain or even enhance the rheological properties of the gelled hydrocarbon fluids with reduced usage of the phosphate esters.

When doped with the novel functional nanomaterials, the rheological properties of the gelled hydrocarbon-based fluids were enhanced from room temperature to 250°F or above. The selected nanomaterials could have van der Waals-like forces, thus strengthening the three-dimensional network of the metal-crosslinked phosphate esters in the gelled hydrocarbon fluid. This way, the overall viscosity of the hydrocarbon-based fluid could increase with lower amount of phosphate esters. For example, the addition of 30ppt (pounds per thousand gallons) of additive-A synergistically improved the viscosity of the gelled oil fluid by about 73% compared to the baseline gelled fluid that did not contain the additive. With additive-A at 30ppt, the amount of the phosphate esters in the fluid could be reduced by 25% without affecting the fluid performance. Besides additive-A, other types of functional nanomaterials including additive-B, additive-C, and additive-D were all found to enhance the rheological properties of the gelled hydrocarbon fluids by as much as about 45%.

The novel gelled hydrocarbon fluid formulas were successfully applied with the crude oil from the field, resulting in viscosity boosts up to about six times. Further discussions about the enhancing behaviors and mechanisms of the selected novel additives in the gelled hydrocarbon fluids and the laboratory test results will be presented in detail.
AGRICULTURE OF THE KEMEROVO REGION
Authors: Столбова Ольга , Stolbova Olga , Рябов Валерий , Riabov Valerii
Published: January 2018

The article presents the characteristics of modern agriculture, which is the basic link of the agroindustrial complex of the Kemerovoregion. It examines the factors that determine its specialization and the main industry of rural economy of Kuzbass. Agriculture plays an important role in ensuring food security in the region. The leading industry is beef farming, beef and dairy cattle, arable farming and grain growing. The Kemerovoregion achieves self-suffi in many agricultural products, some products are exported outside of the region. Prospects of development of agricultural production in Kuzbass are associated with the development of private fodder industry based on the cultivation of forage crops and legumes for intensive and industrial pig, poultry, and beef and dairy cattle breeding and production of succulent feeds for dairy and beef cattle. The development of agriculture will lead to the creation of new processing industries, the formation of a developed agro-industrial complex in the region, which will increase the level of socio-economic development of the region.
Water resource system vulnerability assessment of the Heihe River Basin based on pressure-state-response (PSR) model under the changing environment
Authors: Men Baohui , Liu Haoyue
Published: January 2018

As one of the most important inland rivers in China, the shortage of water resources and ecological deterioration of the Heihe River has increasingly attracted attention, and it is very significant to undertake the water resources sustainable utilization for its vulnerability assessment in the river basin. Using the pressure-state-response (PSR) model, a vulnerability index of the water resources system was developed and used to carry out a vulnerability assessment on the Heihe River in the current year (2010) and the comparison year (2003). The PSR of water resource vulnerability included 11 indexes, which are domestic water quota of urban residents, rural water quota of urban residents, million yuan GDP water consumption, per capita water consumption, ecological water proportion, drought index, per capita water resources, water modulus, water quality grade, water saving irrigation rate, per capita GDP, respectively. The vulnerability of water resources was evaluated by the attribute recognition model. The results show that water resources in the Heihe River Basin were in a quite vulnerable state in both 2003 and 2010 according to the values of scenario A1 (not vulnerable) and scenario B1 (severely vulnerable). It is urgent to protect and restore the water resources system in the Heihe River Basin.
Correlation between nitrous oxide (N2O) emission and carbon to nitrogen (COD/N) ratio in denitrification process: a mitigation strategy to decrease greenhouse gas emission and cost of operation
Authors: Andalib Mehran , Taher Edris , Donohue Joseph , Ledwell Sam , Andersen Mikkel H. , Sangrey Karla
Published: January 2018

The reliability and accuracy of in-situ ion selective electrode and ultraviolet (NOx) probes have been investigated at four different treatment plants with different operational conditions. This study shows that the mentioned probes tend to compromise their accuracy and trending stability at lower NOx of <1.0 mg N/L, which if used as a measuring variable for PI feedback controller for denitrification (biological reduction of nitrate to nitrogen gas), would cause overfeeding the external carbon source. In-situ Clark-type N2O sensors, recently introduced for industrial scale use (Unisense Environment) could potentially open a new horizon in the automation of biological processes and particularly denitrification. To demonstrate the applicability of such probes for automation, two in-situ N2O probes were used in two treatment plants in parallel with NOx-N probes. The effects of operational conditions such as COD/N ratios and the correlation between NOx and N2O were investigated at those plants. N2O production at non-detect dissolved oxygen concentrations and pH of 7–7.2 were found to be a function of influent nitrogen load or the ratio of COD/NINFLUENT. Finally, using an N2O probe as a proxy sensor for nitrates is proposed as a measured variable in the PI feedback in the automation of the denitrification process with a NOx set point of <1.2 mg N/L).
Kisspeptin and its Effect on Mammalian Spermatogensis
Authors: Feng Tao , Bai Jia H. , Xu Xiao L. , Liu Yan
Published: January 2018

Background:

Kisspeptin and its receptor, GPR54, are regarded as key regulators of and catalysts for male
puberty onset, and also fundamental gatekeepers of spermatogenesis in mammals. Consequently, the loss function of
kisspeptin or GPR54 leads to a symptom of Hypogonadotropic Hypogonadism (HH) in human and HH accompanied
by lower gonadotrophic hormone levels, smaller testes, impaired spermatogenesis and abnormal sexual maturation in
mice. Besides its well-recognized functions in hypothalamus before and during puberty, accumulating data strongly
support kisspeptin production in testis, and participation in somatic and germ cell development and sperm functions
as well. This review aims to summarize recent findings regarding kisspeptin activity in the testes and sperm function.

Methods:

We undertook a keyword search of peer-reviewed research literature including data from in vivo and
in vitro studies in humans and genetically modified animal models to identify the roles of kisspeptins in male
reproduction.

Results:

A plethora of studies detail the role of kisspeptins and GPR54 in mammalian spermatogenesis in vivo and in
vitro. This review identified recent findings regarding the kisspeptin system in male gonads, and regulation of kisspeptin
in testicular physiology and male reproductive defects and disorders.

Conclusion:

The findings of this review confirm the importance role of kisspeptins in male fertility. Understanding
their biphasic roles in testis may help to consider kisspeptins as potential pharmacological targets for treating human
infertility.
Cross-regulatory Circuit Between AHR and Microbiota
Authors: Ji Jian , Qu Hao
Published: January 2018

Background:

The gut microbes have a close symbiotic relationship with their host. Interactions between
host and the microbiota affect the nutritional, immunological, and physiological status of the host. The Aryl Hydrocarbon
Receptor (AHR) is a ligand activated transcription factor that mediates the toxicity of xenobiotics. Recently,
the relationship between the gut microbiota and AHR has attracted the attention of many researchers.

Methods:

We undertook a structured search of bibliographic databases for peer-reviewed research literature.

Results:

We found and reviewed 49 peer-reviewed papers dealing with the major aspects related to the crosstalk
between AHR and microbiota. The AHR influences the intestinal microbiota population and mediates host-microbe
homeostasis. Interestingly, the gut microbiota also produces ligands of AHR from bacterial metabolism and thereby
activates the AHR signaling pathway.

Concusion: This review presents current knowledge of the cross-regulatory circuit between the AHR and intestinal
microbiota. The findings of this review confirm the importance of AHR-microbiota interactions in health and disease.
Anticancer Activity Study of Chromone and Coumarin Hybrids using Electrical Impedance Spectroscopy
Authors: Bouhenna Mustapha M. , Mameri Nabil , Pérez Mónica V. , Talhi Oualid , Bachari Khaldoun , Silva Artur M.S. , Luyten Walter
Published: January 2018

Aims: Oncology treatments aim at selective toxicity for tumor (compared to normal) cells, and chromone-
coumarin hybrids have shown such activity.

Methods:

In this study, we test a novel series of synthetic chromone and coumarin derivatives (1–9) for cytotoxic
activity against a panel of tumor cell lines (MCF-7, A549, HepG2, HTC-116, B16 and Caco-2) opposed to
non-tumor cells (HEK-293t). Electrical impedance spectroscopy was used to monitor cell viability in real time.

Results:

Compound 8 showed the most potent activity, and it significantly diminished cancer cell proliferation
and viability in different cell lines. It induced apoptosis in a dose-dependent manner, as shown by Western blot
and flow cytometry.

Conclusion:

Electrical impedance spectroscopy appears to be a convenient tool for in vitro cytotoxicity analysis,
which could be useful for identifying drug effects and side effects during early phases of drug discovery and
development.
Faktor-faktor yang mempengaruhi kearifan konselor menurut perspektif calon konselor etnis Jawa
Authors: Herdi Herdi , Kartadinata Sunaryo , Taufiq Agus
Published: January 2018

Tujuan penelitian ini adalah mengeksplorasi faktor-faktor yang mempengaruhi kearifan konselor menurut perspektif calon konselor etnis Jawa. Penelitian menggunakan metode deskriptif jenis survey. Sampel penelitian berjumlah 270 calon konselor etnis Jawa semester enam dari 11 Program Studi Bimbingan dan Konseling di Indonesia. Sampel penelitian dipilih menggunakan teknik purposive sampling. Pengumpulan data menggunakan angket yaitu Skala Anteseden Kearifan Konselor yang berbentuk skala lima jenjang. Teknik analisis data menggunakan statistik deskriptif dan analisis faktor eksploratoris. Hasil penelitian menunjukkan terdapat enam faktor yang mempengaruhi kearifan konselor menurut perspektif calon konselor etnis Jawa. Faktor-faktor yang dimaksud dinamakan: (1) kepribadian dan kecerdasan, (2) pengalaman, (3) atribut pribadi, agama, dan spiritual; (4) keterampilan metakognitif (berpikir kritis dan mendalam); (5) konteks fasilitatif; dan (6) kepakaran (profesionalitas). THE FACTORS AFFECTING A COUNSELOR’S WISDOM IN THE PERSPECTIVES OF JAVANESE PRE-SERVICE COUNSELORSAbstractThe purpose of this research is to explore the factors affecting a counselor’s wisdom in the perspectives of Javanese pre-service counselors. The research adopted a descriptive method of survey. The sample included 270 of the sixth semester of Javanese pre-service counselors from 11 Guidance and Counseling Study Program in Indonesia. Data were collected using questionnaire, which is Counselor Wisdom Antecedents Scale, in the form of five-level scale. The data were analyzed with descriptive statistics and exploratory factor analysis. The findings show that there are six factors affecting a counselor’s wisdom in the perspectives of Javanese pre-service counselors. The six factors named: (1) personality and intelligence, (2) experience, (3) personal attributes, religiosity, and spirituality, (4) metacognitive skills (critical and in-depth thinking skills), (5) context-facilitative, and (6) expertise (professionality).
Outsourcing the Remote Management of Cardiac Implantable Electronic Devices: Medical Care Quality Improvement Project (Preprint)
Authors: Giannola Gabriele , Torcivia Riccardo , Airò Farulla Riccardo , Cipolla Tommaso
Published: January 2018

BACKGROUND

Remote management is partially replacing routine follow-up in patients implanted with cardiac implantable electronic devices (CIEDs). Although it reduces clinical staff time compared with standard in-office follow-up, a new definition of roles and responsibilities may be needed to review remote transmissions in an effective, efficient, and timely manner. Whether remote triage may be outsourced to an external remote monitoring center (ERMC) is still unclear.

OBJECTIVE

The aim of this health care quality improvement project was to evaluate the feasibility of outsourcing remote triage to an ERMC to improve patient care and health care resource utilization.

METHODS

Patients (N=153) with implanted CIEDs were followed up for 8 months. An ERMC composed of nurses and physicians reviewed remote transmissions daily following a specific remote monitoring (RM) protocol. A 6-month benchmarking phase where patients’ transmissions were managed directly by hospital staff was evaluated as a term of comparison.

RESULTS

A total of 654 transmissions were recorded in the RM system and managed by the ERMC team within 2 working days, showing a significant time reduction compared with standard RM management (100% vs 11%, respectively, within 2 days; P<.001). A total of 84.3% (551/654) of the transmissions did not include a prioritized event and did not require escalation to the hospital clinician. High priority was assigned to 2.3% (15/654) of transmissions, which were communicated to the hospital team by email within 1 working day. Nonurgent device status events occurred in 88 cases and were communicated to the hospital within 2 working days. Of these, 11% (10/88) were followed by a hospitalization.

CONCLUSIONS

The outsourcing of RM management to an ERMC safely provides efficacy and efficiency gains in patients’ care compared with a standard in-hospital management. Moreover, the externalization of RM management could be a key tool for saving dedicated staff and facility time with possible positive economic impact.

CLINICALTRIAL

ClinicalTrials.gov NCT01007474; http://clinicaltrials.gov/ct2/show/NCT01007474
Experience of Using an App in HIV Patients Older Than 60 Years: Pilot Program (Preprint)
Authors: Olalla Julián , García de Lomas Jose María , Márquez Efrén , González Francisco Jesús , Del Arco Alfonso , De La Torre Javier , Prada Jose Luis , Cantudo Francisca , Martín María Dolores , Nieto Miriam , Perez Stachowski Javier , García-Alegría Javier
Published: January 2018

BACKGROUND

New technologies can promote knowledge of HIV infection among patients suffering from this disease. Older patients with HIV infection represent an increasingly large group that could benefit from the use of specific apps.

OBJECTIVE

The aim of the study was to observe the acceptability and use of a mobile app on HIV infection in patients at least 60 years old and offer them the possibility of anonymously establishing contact with their peers.

METHODS

A series of clinical and psychosocial parameters were studied in 30 HIV-infected patients of over 60 years. The patients must be at least 60 years old, with a follow-up in the outpatient clinic for at least 1 year and without pathologies that limit his or her life expectancy to less than a year. They must know how to read and write. To be part of the group assigned to the app, they had to have their own smartphone and confirm that they were connected to the internet from that device. Overall, 15 of them were randomized to use an app and 15 were in the control group. All tests were repeated after 6 months.

RESULTS

The median age of patients was 66.5 years. Among them, 29 patients had an undetectable viral load at baseline. The median number of comorbid diseases was 2. Overall, 11 of them lived with their partners and 19 lived alone. They spent an average of 5 hours a day sitting down, and 56% (17/30) of them referred high physical activity. They scored 4 out of 5 for general quality of life perception. Moreover, 80% (24/30) presented high adherence to their treatment, and the average number of concomitant medications was 5. In the 6-min walking test, they covered a distance of 400 meters, and 3 of them desaturated during the test. The 15 patients made frequent use of the app, with 2407 sessions and an average of 7 min and 56 seconds time of use with a total of 13,143 screen views. During the 6 months of the trial, 3 non-AIDS events took place. There were no significant modifications to body mass index, blood pressure measurements, lipid profile, or immuno-virology information data. There were no differences in the questionnaire scores for perception of quality of life, confessed physical activity, or antiretroviral treatment (ART) and non-ART treatment adherence.

CONCLUSIONS

Significant differences between studied parameters were not objectified in these patients, possibly because this trial has significant limitations, such as a small sample size and only a brief follow-up period. However, patients did use the app frequently, making this a possible intervention to be proposed in future subsequent studies.