bluuebunny/crossref_metadata_2025_split huggingface dataset:
Economic Evaluation and Uncertainty Assessment of Lost Circulation Treatments and Materials in the Hartha Formation, Southern Iraq
Authors: Alkinani Husam H. , Al-Hameedi Abo Taleb , Dunn-Norman Shari , Flori Ralph E. , Hilgedick Steven A. , Amer Ahmed S. , Alsaba Mortadha T. 
Published: October 2018

Abstract
It is recognized that there is no single solution to lost circulation, and most treatment and trial-and-error. However, the screening guide presents a high-level ‘go to’ document with coherent guidelines, which engineers can utilize in making decisions regarding lost circulation treatments in major oil fields. The aim of this work is to describe how mud engineers can use the decision tree analysis (DTA) to evaluate and select the best treatments path for mitigating mud losses.
Lost circulation events of Southern Iraq oil fields were statistically analyzed to determine treatment effectiveness. Also, the cost of each treatment, as well as the NPT that is associated with the treatment, is considered in this study. Data from over 1000 wells were gathered from various sources and reports; the
treatments were classified by scenario -partial, severe, and complete losses - as well as cost, efficiency, and formation types. This paper is developed based on probabilities, expected monetary value (EMV), and decision tree analysis (DTA) to recommend the best-lost circulation treatments path for each type of losses.
Traditionally, lost circulation in Southern Iraq area has been treated in a multitude of ways without consistent methodology. This analysis identifies and ranks the most effective treatments to create a "best" method/product recommendation and a flowchart suggesting additional measures in treating losses to optimize success and reduce overall cost and NPT. This paper presents the best treatment for each scenario - partial loss, severe losses and complete losses - both for product selection and engineering.
This paper utilizes probability and economics in the decision-making process. This is the first study that considers a detailed probability and cost to treat the lost circulation problem. Thousands of treatment scenarios for each type of losses are conducted, and the EMVs for all scenarios are calculated. For each type of losses, the lowest EMV treatment strategy- that is practically applicable in the field and makes sense- is selected to be used to treat each type of losses to minimize NPT and cost. If the losses didn't stop after utilizing the proposed treatment strategies, it is recommended to use liner hanger to isolate the losses zone and then continue drilling.
One challenge in drilling wells in Southern Iraq oil fields is the inconsistency of approaches to the lost circulation problem. Therefore, the result of this data analysis provides a path forward for Southern Iraq area lost circulation events and suggests probable methods that can be used in similar formations globally. Additionally, the methodology can be adapted to studying other types of formations and drilling challenges have the same geological properties in any major oil field.
Transient Modelling and Sensitivity Analysis of Influxes in Backpressure MPD Systems
Authors: Gomes Dalila , Frøyen Johnny , Fjelde Kjell , Bjørkevoll Knut 
Published: October 2018

Abstract
A transient flow model capable of modeling gas solubility will be used to perform a sensitivity analysis of kick behavior in a subsea backpressure MPD system when using oil based mud. The parameters of interest are choke pressures, pit volume, and return rates. At HPHT conditions, gas kicks can be entirely dissolved in oil based mud. However, when being circulated upwards, free gas will emerge at a certain depth. The required choke pressure to maintain a constant bottomhole pressure depends on the amount of gas released from the mud and where this occurs. Another parameter that impacts both choke pressure and return flow is the geometry, whether we have a wide riser for subsea MPD or are considering an MPD operation from a fixed installation with a narrower geometry. In this paper, the riser geometry will be varied. The paper will contribute in showing how transient models can assist in the planning of MPD operations. It will also provide insight into influx behavior and its impact on surface parameters with focus on oil based mud.
Investigating the Influence of Wettability and Direction on Supercritical CO2 Trapping for Supercritical CO2-Brine Imbibition Process at Pore Scale for Bentheimer Sandstone
Authors: Jahan Farjana , Ahmed Shakil , Hossain Mofazzal 
Published: October 2018

Abstract
Wetting properties of various reservoir rocks strongly influence the efficiency and security of geological storage of carbon dioxide in deep saline aquifers. Numerical simulation of Carbon Capture and Storage (CCS) has become a considerable research option now-a-days due to less time and cost-effective outcomes compare to traditional laboratory based experiments. This study provides a Computational Fluid Dynamics (CFD) methodology for the pore-scale displacement mechanism of supercritical CO2 under different wetting conditions and quantify the effect of wettability and direction of flow on supercritical CO2 trapping.
A 3-Dimensional visualization software is used to build surface mesh from the micro-pores of the Bentheimer sandstone. A module of a commercial CFD software is used to generate volume mesh from the surface mesh and another module from the same CFD software is used to perform imbibition processes (supercritical CO2/brine) through the Bentheimer sandstone. Full Navier-Stokes equations are solved by using Eulerian-Eulerian multiphase transient flow approach. Free surface flow model is used to integrate the effect of capillary forces. This model determines the pressure gradient at the two-phase interface. The flow is assumed to be laminar, isothermal and there is no mass transfer between phases.
The initial condition of the imbibition processes was obtained from a drainage process for a strongly water-wet system. For this, a Bentheimer sandstone was completely filled with brine and supercritical CO2 was injected. The simulation was stopped when brine was drained by supercritical CO2 and the system reached the steady state conditions. This phase distribution was used as an initial boundary condition for the imbibition processes. The imbibition processes were performed in two opposite direction for different contact angles (100° and 110°). The effect of wettability and direction of brine on supercritical CO2 trapping were observed. The residual saturation of supercritical CO2 was significantly different in two opposite direction of brine flow. In the reverse imbibition process, normalized residual supercritical CO2 saturation values are increased but, the amount of normalized trapped supercritical CO2 values are decreased. It was mainly due to the amount of normalized free supercritical CO2 saturation values (which were equal to the difference between normalized residual supercritical CO2 saturation and normalized free supercritical CO2 saturation values).
Review of Water Saturation Calculation Methods in Shale Gas Reservoir
Authors: Yu Hongyan , Wei Xiaolong , Wang Zhenliang , Rezaee Reza , Zhang Yihuai , Lebedev Maxim , Iglauer Stefan 
Published: October 2018

Abstract
The gas content in shale reservoir is of great importance in reservoir evaluation. Shale reservoir has various gas including free gas, adsorpted gas and soluted gas. Free gas take an important part for the total gas content. Hence, we investigated three equations for water saturation calculating and compared and improved them based on theoretical analysis in order to find a siutable one for the shale reservoir characterization. The results indicate that the Archie formula has several limitations applied to complex pore structure, which leads to high water saturation. Since the Archie formula was proposed by experimental data in pure sandstone without enough consideration about the clay of shale reservoir. The Waxman-Smits is suitable to shale gas reservoirs through theoretical analysis, but there are several uncertain parameters. The conductivity of formation water is necessary parameter in calculation of formation water saturation, but calculating the conductivity of formation water is difficult in shale gas reservoir because of its intricate characterization of pore structure and conductivity. Waxman-Smits model take account for the clay conductivity, but there are several uncertain parameters which are hard to obtained, resuting high error. For instance, the equivalent conductivity of exchange cations (B) and the capacitance of exchange anions (Qv) can not be defined accurately relied on experimental calculation, which causes indefinite influence on results. Thus, we concluded that selecting the improved Indonesia equation is a better method to calculate water saturation. This study provided a comprehensive analysis and an accurate way for water satruartion evaluation in shale reservoir.
Modelling of Inflow Control Devices: From the Flow Loop to the Simulator
Authors: Dimitrov Sankoff Roumen , Bijani Behrooz , Di Martino Gianluca , Watson Julie , Scott Marshall Craig 
Published: October 2018

Abstract
The intent of this work is to outline the workflow that engineers can apply in the selection and modelling of inflow control devices (ICDs) for use in completion design. It provides a step-by-step guide and examples of how to address the key challenges in the field of modelling of ICDs, namely: the choice of ICD technology that is most suitable for the particular well; the process of building a custom ICD performance model and import into the reservoir simulator; considerations in setting up the simulation model; and, verification of the results.
The paper highlights the risk of using empirical ICD models, available in reservoir simulators, in the early stages of evaluating inflow control technology. It then demonstrates that the decision on whether or not an inflow control is required, and what type, can be made without resorting to these built-in empirical models in reservoir simulators.
The paper introduces a new approach to evaluation, comparison and modelling of inflow control devices of different types and geometry. Focused on simplicity and accuracy, the method of ICD characterisation is described, as is how to use this characterisation to generate input to the reservoir simulator. A method for verification of the output from the reservoir simulator is also presented.
The application of this modelling approach is illustrated through a case study on evaluating inflow control technology in a mature oil reservoir.
Bio Enhanced Energy Recovery Technology for Clean and Efficient Energy Production
Authors: Clemens Langbauer , Herbert Hofstätter , Albina Mukhamedzianova 
Published: October 2018

Abstract
The demand for environmentally friendly and efficient oil and gas production, especially in unconventional reservoirs, is continuously increasing. Conventional hydraulic fracturing jobs use numerous different harmful (U.S. Environmental Protection Agency, 2016) chemicals to stabilize the fracturing fluid and to maintain its proppant caring capacity. The Bio-Enhanced Energy Recovery (BEER®) fracturing technology is a new technology for clean and efficient energy recovery in tight oil and shale gas reservoirs using biological substances, without the use of environmentally harmful chemicals.
This paper shows the potential of the BEER® technology in a tight gas sandstone reservoir with the help of the 3D simulator GOHFER® and laboratory tests. The technology itself consists of two essential parts. On the one hand, a biological hydraulic fracturing fluid to create the fracture and to carry the proppants is just a mixture of a few harmless components. On the other hand, special proppants, based on silicon dioxide, are applied to keep the fracture open.
Experiments and lab tests have shown the high potential of the fluid. Fluid rheology, caring capacity, breaking behavior and other relevant properties are examined. The investigations of the proppants result in a very high compressive strength, narrow size range, perfect sphericity at a much lower price, compared to the common commercially available products. Based on those results by the usage of the simulator GOHFER®, the fracturing job efficiency of the BEER® technology is comparable to the performance of the standard fracturing technology. Reservoir properties, the treatment job design, the 3D fracture geometry and post-treatment production enhancement are investigated. A sensitivity analysis of gross fracture length, propped cut-off fracture length, and fracture conductivity confirms the significant potential of this technology.
The results presented here indicate that the proposed technology is indeed suitable for performing environmentally friendly and clean hydraulic fracturing jobs, resulting in higher production rates at much lower costs than the conventional technology.
Novel Nano-Surfactant Formulation to Overcome Key Drawbacks in Conventional Chemical EOR Technologies
Authors: Mashat Afnan , Gizzatov Ayrat , Abdel-Fattah Amr 
Published: October 2018

Abstract
This article reports on a novel simple method for transforming the high-salinity-incompatible petroleum sulfonates into a persistently stable oil-swollen micelles, referred to here as nanosurfactant. We present and discuss the effect of three different nanosurfactant formulations on the interfacial tension (IFT) between high-salinity water and crude oil, their phase behavior, and the effect of their dilution on IFT to assess their ability to reduce mobilize oil after injection into high-salinity and temperature reservoirs.
The three nanosurfactant formulations were prepared in high-salinity water following a direct-mixing procedure in which solutions in fresh water of 5 wt% petroleum sulfonate in mineral oil and three 4 wt% zwitterionic co-surfactants were mixed with high-salinity water at room temperature to give a combined concentration of all active ingredients of 0.2 wt%. The IFT between crude oil and different nanosurfactant formulations was measured using a spinning drop interfacial tensiometer at 90°C. IFT was measured every 5 minutes while the oil drop was spinning at ~4000 rpm. The phase behavior was investigated by monitoring the turbidity and UV absorbance changes in a system of crude oil atop of the nanosurfactant formulation over time at 100°C without any mechanical mixing.
The particle size of the three nanosurfactant formulations is in the range of 40 to 80 nm, depending on the co-surfactant used. All formulations were persistently stable, colloidally, and chemically under high-salinity (~56,000 ppm) and temperature (100°C) for more than four months. All formulations showed substantial reduction in IFT with crude oil compared to high-salinity water alone. Dilution with high-salinity water up to five times further reduced the IFT, suggesting improved performance after injection into the reservoir. This behavior was consistent with the observed gradual decrease in surface tension of the nanosurfactant formulation as its concentration decreases toward the CMC value. Phase behavior experiments showed enhanced formation of homogeneous micelles at 100°C without the aid of any mixing. Our results demonstrate the ability of nanosurfactants to solubilize oil under typical carbonate reservoir conditions. Their colloidal nature allows them to migrate deeper in the reservoir compared to conventional surfactants due to size exclusion and chromatographic effects.
Nanosurfactants are novel oil-swollen micelles of the inexpensive and abundant petroleum sulfonate salts that are efficient in reducing IFT under typical carbonate reservoir conditions. The formulation method can be extended to other surfactants and chemical treatments that are incompatible with high-salinity water at high temperatures. Their nanoparticle character and colloidal behavior suggest their ability to migrate and penetrate deep in the reservoir. Nanosurfactants can therefore help overcome some of the most critical drawbacks in conventional chemical EOR technologies.
Supramolecular & Oil Displacement Fluid for Hydraulic Fracturing
Authors: Cui Weixiang , Zou Honglan , Wang Chunpeng , Yang Jiang , Yan Jun 
Published: October 2018

Abstract
This paper studied a new fracturing fluid based on a supramolecular complex between associative polymer and viscoelastic surfactant (VES). The combination of VES and associative polymer synergistically enhances the viscosity several times more than that of the individual components alone. The fluid system was optimized by experimental design. The microstructure of wormlike micelle and complex formation was verified by electron microscopy. The proppant transport test in a large-scale fracture simulator showed good proppant suspension ability. After fracturing, the nano- surfactant molecule in the liquid have a high surface energy, which can play a good oil displacement effect in the crack.
The fluid has 50% lower formation damage than that of conventional guar. The fluid was prepared with less additives and formed gel instantly, which can be mixed on the fly in the field. The gel can be completely broken with almost no residue. By flooding and [1]nuclear magnetic resonance experiments results, compared to the conventional fracturing fluid and water, oil displacement efficiency can be increased by 12% to 20%, more micro-pores in the oil and gas drive for higher pressure stimulation effect for tight oil reservoir. Field application of the new fracturing fluid in 10 tight gas wells showed the enhancement of gas production over 100%. The fluid has 20% lower friction pressure than that of guar fluid. Hence, the new supramolecular fluid is an effective fracturing fluid.
Supramolecular fracturing fluid provides a new fracturing system with less formation damage to fracturing operation. This paper will be beneficial to all engineers and technologists who are currently working at tight gas stimulation applications.
Defining and evaluating the social value of regional water resources in terms of emergy
Authors: Wu Zening , Di Danyang , Lv Cuimei , Guo Xi , Wang Huiliang 
Published: October 2018

Abstract
The social value of water resources must be considered when reforming water prices, improving water policy, protecting water resources and devising allocation methods. However, current social value theories for water resources are often unsound. The social value of water resources is defined here based on social system theory. Energy flow within a combined social–ecological system is analyzed, and an emergy analysis method for ecological economics is introduced for unified quantification and to improve the accounting method of the social value of water resources. Taking Zhengzhou in east-central China as an example, the social value of water resources is calculated for 2015. The water resources' total social emergy was 6.04 × 1021 solar equivalent joules (sej) and the unit value was 6.58 × 1012 sej/m3. This corresponds to 3.88$/m3, indicating that the social value of water resources is enormous. This paper proposes that the social value of water is an important component of its ecological economic value, and its social value should therefore be considered by water policy makers. Research of this type can be effective in helping to protect water resources and encourage efficient water use.
Rapid detection of Cyanobacteria by recombinase polymerase amplification combined with lateral flow strips
Authors: Li Jingjing , Wang Chunming , Yu Xin , Lin Huirong , Hui Chen , Shuai Li , Zhang Shenghua 
Published: October 2018

Abstract
Cyanobacteria are one of the major groups of algae causing algal blooms. In this study, we developed a rapid method for detecting Cyanobacteria using a recombinase polymerase amplification (RPA) method coupled with lateral flow (LF) strips. After releasing cyanobacterial DNA from cells using a freeze-cracking method, DNA was amplified using the RPA method. Next, the RPA products were detected using the LF test. LF-RPA successfully amplified the DNA of eight cyanobacterial species and detected their presence in the sample with high specificity, distinguishing them from five non-cyanobacterial species. The method could detect cyanobacterial DNA in water samples containing as low as 0.01 cell/mL Cyanobacteria, making the method more sensitive than polymerase chain reaction (PCR), which required cell densities of at least 104 cell/mL. LF-RPA could amplify and detect cyanobacterial DNA at any temperature in the range 30–45 °C in just 30 min and without the need for a thermal cycler. The method developed in this study is simple, rapid, and effective for on-site testing of Cyanobacteria, which may become a routine measurement in efforts to detect and treat harmful algal blooms.
Pharmacoinformatic Approaches to Design Novel Inhibitors of Protein Kinase B Pathways in Cancer
Authors: Akhtar Noreen , Jabeen Ishrat 
Published: October 2018

Background:
Protein kinase B (PKB/Akt) belongs to the AGC superfamily of related serine/
threonine kinases with three structurally homologous mammalian isoforms, Akt1 (PKBα), Akt2
(PKBβ), and Akt3 (PKBγ). Besides sharing a similar structural topology, the difference in their
physiological functions and tissue distribution makes Akt a cardinal node in diverse signaling pathways
involving cell growth, survival, and proliferation. Various immunohistochemical studies have
reported that the constitutive hyperactivation of Akt signaling is responsible for several types of human
cancer, poor prognosis, as well as chemotherapeutic and radiotherapeutic resistance. Thus, inhibition
of Akt activation represents a promising concept to induce cell apoptosis in various cancers
and evade chemotherapeutic resistance. However, development of potent and selective inhibitors of
Akt kinases as suitable antagonists remained gloomy and thus, only handful of compounds were selected
for the clinical investigation but none of them could reach the market for routine clinical usage
to circumvent cell proliferation and resistance to chemotherapeutic agents in cancer. Recent reports
on achieving isoform selectivity by designing inhibitors against PH domain of Akt, together
with availability of crystal structures of the PH domain of Akt1, open the possibility of structurebased
design.

Methods:
In this article, various biological regulatory networks by which Akt and its substrates
regulate cell growth and survival and several SAR and QSAR strategies in combination with molecular
docking studies on selective inhibitors of Akt subtypes have been highlighted to further
probe the selectivity of ligand-Akt subtypes interactions.

Results:
Structure-based drug design studies revealed that the interactions of structurally diverse
compounds with Glu121, Ala123, Asn171, Asp184, Glu228 and Ala230 amino acid residues in CAT
domain and Arg23, Arg25, Lys30, Asn54 and Arg86 amino acid residues within PH domain play an
important role in attaining significant inhibitory potency.

Conclusion:
Isoform selective inhibition of Akt might have clinical significance and thus, should be
taken into account in future investigations. Moreover, an up to date isoform selective chemical data
is required to further validate already reported isoform selective binding hypothesis.