bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fracturing Carbonate Reservoirs: Acidising Fracturing or Fracturing with Proppants?
Authors: Jeon Jiwon , Bashir Muhammad Omer , Liu Junrong , Wu Xingru 
Published: August 2016

Abstract
Carbonate reservoir with low permeability is developed using fracturing technology to effectively stimulate the reservoir for a higher productivity. However, as the carbonate reservoir features extreme heterogeneity, not every fracture is created equally as is obtainable through acidizing fracturing or using proppant. The objective of this study is to help make the decision among acid fracturing or proppant fracturing, to achieve an economically and operationally feasible treatment through extensive research of field cases on critical factors and numerical simulation.
An ideal fracturing method of a carbonate reservoir should yield a high conductive fracture with a potential for long production duration under depletion scenario within an economic limit. We first review real field cases to identify critical parameters affecting fracture geometry and productivity; then we validate and quantify their individual effectiveness using 3D synthetic models with numerical simulation. In the simulation work, both treatments are evaluated by simulating the production of the reservoir for 1,500 days post treatment. Results are compared for different reservoir parameter variations including porosity, permeability, temperature, depth and young's modulus. Simulation of the field is continued for 1,500 days after the treatment to see the effect of the production enhancement for both types of treatment. This is also done to include long term loss of fracture conductivity and its effect on the overall production. Fracture geometry from each case is also analyzed and compared to the base case scenario.
Even though hydraulic fracturing and acidizing technologies have been the dominant stimulation methods in unconventional resources and many variants have been developed, there is still no well-defined guideline which can help an operator to select the stimulation techniques suitable for their particular fields. This paper focuses on factors influencing decision making on the stimulation of carbonate reservoirs based on reservoir characterization. The advantages and limitations of proppant fracturing and acid fracturing are compared based on field applications, which can enable an operator to make quick and informed decision on which stimulation should be used. Numerical effort confirmed and quantified our observations. Comparisons have been drawn on different types of proppant and acid treatments and their effectiveness on the target reservoir. The study eventually comes up with identifying main factors of reservoir for treatment selection and recommendations are presented from these findings that which type of reservoir is best suited for which type of treatment.
The novelty of the study is summary of previous field cases with a clear guideline on making decision in carbonate reservoir stimulation. As a further extension to this study, PVT data can also be included to see the extent of reservoir fluid change effect on the outcome of the treatment.
Laboratory Testing and Numeric Simulation on Laws of Proppant Transport in Complex Fracture Systems
Authors: Li Nianyin , Li Jun , Zhao Liqiang , Luo Zhifeng , Liu Pingli , Guo Yujie 
Published: August 2016

Abstract
Stimulated reservoir volume fracturing, in unconventional gas and tight oil development, is a key technology. Injecting low viscosity sand-laden fluid of high flow rate, it can form complex fracture networks. Therefore, placement of proppant deep into the complex fracture networks brings a conductive path for production enhancement and reduces flowing resistance when fluid flowing form rock matrix to wellbore.
At current, it is still unclear that sand features of low viscosity sand-laden fluid of high flow rate, and especially for proppant transport in subsidiary fractures are also not clearly understand. In this study, we fully think about the practical condition of engineering. Thus, in terms of similarity criterion of geometry and Reynolds number, we build a large scale of proppant placement in visualization complex fracture networks device which can changes angles of fractures, width of fractures and numbers of fractures. Due to the single factors experiment, this paper will discuss a series tests to evaluate proppants transport in complex fracture networks. Different slick water treatment tests are simulated by pumping sand slurry through the visualization complex fracture networks device while varying parameters of perforation, angles of fractures, proppant size, pump rate and proppant concentration. From the experiment, treatment tests which are used in variable factors can obtain different laws about traction carpet feature, traction carpet areas, balance hight and balance time in complex fracture networks. This paper also describes a 3-D physical model. This model is designed by SolidWorks software and using grid software to make complex fracture grids. Afterwards, using fluent software to simulate proppant concentration distribution field in the model of complex fracture networks. In addition, comparing the results between physical model and numerical model, the results can reveal, during the process of SRV, the law of proppant placement in complex fracture networks and serve as guidelines for engineering design.
A New Acid Fracturing Fluid System for High Temperature Deep Well Carbonate Reservoir
Authors: Gao Ying , Lian Shengjiang , Shi Yang , Yang Xianyou , Zhou Fujian , Xiong Chunming , Li Futao , Han Xiuling , Zhang Na 
Published: August 2016

Abstract
When a high temperature deep well carbonate reservoir is stimulated with conventional acid fluid, some unfavorable behaviors often occur, such as high acid-rock reaction rate, short effective reaction distance of live acid, failure of acid etching in the acid fracture front, and serious corrosion to downhole string. This paper presents a new acid fracturing fluid system. This system consists of the acid-generator SGA-E, the optimized polymeric thickener CHJ-1 and the cross-linking agent SJL-1. With the performance of water-based fracturing fluid, this system can be used as prepad during acid fracturing. Moreover, this system has weak or no acidity at low temperature and slow release of H+at high temperature (120-150°C) in fractures, Its ultimate effective acid concentration is about 8% which is capable of effective acid etching. During pumping, this system shows less corrosion to the string, so few corrosion inhibitor is required. This new acid fracturing fluid system can achieve effective acid etching of a whole fracture, so as to increase the stimulated reservoir volume.
A New Liquid CO2 Based Gel Fracturing Fluid with Cylinder Micelles Structure
Authors: Lu Yongjun , Cui Weixiang , Ding Yunhong , Xu Jianguo , Duan Yongwei 
Published: August 2016

Abstract
Liquid carbon dioxide (CO2) fracturing technology is one of the waterless fracturing technologies. It has the advantages of avoiding the use of water, reducing damage, and increasing production by improving the reservoir pressure. However, the low viscosity of liquid CO2 and the difficulty to pump proppant are the main technical challenges. No conventional thickening agent can provide the required thickening used in 100% liquid CO2. In this paper, the problem of thickening gelled liquid CO2 has been solved by developing a new surfactant and thickening agent. Surface active agent can make the liquid CO2 gel by forming wormlike micelle or cylinder micelles structure. The cylinder micelles enhance the viscosity through entanglement inter-actions above a critical concentration.
Rheology and friction properties of liquid CO2 gel are evaluated through high pressure pipeline rheological experimental device. The viscosity of liquid CO2 gel fluid changes under different pressures (10 to 20MPa), temperatures (0 to 100 °C)and different shear rates. The experiment result shows that the effective viscosity of liquid CO2 gel fluid is between 7.654 ~ 20.012mPa.s. The liquid CO2 was thickening with viscosity increase at 86 to 498 times under the same conditions.
The field application of the new liquid CO2 based gel fracturing fluid in two wells of Jilin oil field in China shows that the production has been increased over 100%. 19.8 m3 of proppant has been successfully pumped to the reservoir in one well, and the mean proppant concentration is 6.8%.
Liquid CO2 based gel 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 waterless fracturing applications.
Hydraulic Fracture Diagnosis Using Partitioning Tracer in Shale Gas Reservoir
Authors: Tian Wei , Shen Tong , Liu Junrong , Wu Xingru 
Published: August 2016

Abstract
Chemical tracer is an alternative technique for hydraulic fracture diagnosis other than tiltmeter and microseismic mapping. Fracture volume is an essential parameter for stimulation optimization and production forecast. In our previous work, we proposed a simple, cost-effective method to assess the fracture volume using partitioning chemical tracer. In the hydraulic fracturing stage, a partitioning chemical tracer slug is injected along with the fracking fluid. In the created hydraulic fracture, the tracer partitions in both vapor and liquid phases and flow back in the production stage. By analyzing the tracer production data, we could estimate fracture volume and leak-off volume.
This work will first investigate chemical tracer selection criteria for the purpose of fracture volume diagnosis. Tracer partition coefficient and tracer adsorption are the main considerations. Our results suggest a careful section is needed for partition coefficient, balancing the estimation accuracy and investigation area. In addition, the selected tracer should have negligible adsorption. Numerical simulation is another way to interpret tracer test. In the second part of this paper, we propose a modified Random Walk Particle Tracking (RWPT) algorithm to simulate the partitioning chemical tracer transport with multiple mobile phases. Output obtained through the RWPT is identical with analytical solution and its tracer critical breakthrough time is more accurate than the result from the finite-difference based simulations.
A Statistical Approach to Fracture Optimization of the Glauconite Formation in Southern Chile
Authors: Alqatrani G.. , Britt L. K. , Otzen G.. , Guzman M.. , Kusanovic G.. , Dunn-Norman S.. 
Published: August 2016

Abstract
The Glauconite Formation is a low permeability unconventional resource in southern Chile. Like many unconventional reservoirs outside the United States establishing commercial production from the Glauconite Formation was difficult given the nature of the reservoir, the availability of equipment and materials, and the logistics associated with drilling, completing, and fracture stimulating wells in a remote area like Tierra del Fuego in southern Chile. To be successful fracture stimulating wells in this environment it was critical to develop a deep understanding of the relationship between reservoir quality, completions, mini-frac analysis, fracture design, execution, and post fracture production data. To this end, a database was developed and the key completion and fracture stimulation parameters were captured.
This paper describes a statistical evaluation of nearly seventy wells fracture stimulated in the Glauconite Formation in southern Chile. The analysis will attempt to discover the key fracture design parameters that drive well performance in this unconventional resource. Some key questions to be addressed include: What type of fracture fluid (cross-linked, linear gel, hybrid, or treated water frac's) results in better well performance? What is the effect of treatment volume on well performance? What is the effect of proppant volume, proppant type, and proppant size on well performance? Is there a relationship between fracture fluid efficiency, load recovery, reservoir quality and well performance? These and more questions will be addressed in this paper.
This paper will also use the information in the database and the results of the statistical evaluation to conduct a fracture optimization study and determine the optimum fracture design which maximizes well performance and economic objectives. This work benefits the petroleum industry by: Conducting a statistical analysis of the important completion and fracture stimulation parameters to determine the success drivers for well performance in an unconventional tight gas reservoir,Utilizing the statistics to identify well completion and fracture stimulation risks and risk mitigation strategies,
Analyzing Transient Pressure and Rate Responses of Tight Oil Reservoirs Using Comparative Numerical, Analytical and Semi-Analytical Methods
Authors: Zhu Yue , Zhao Gang 
Published: August 2016

Abstract
Low to ultra-low permeability tight oil reservoirs have recently become a significant source of hydrocarbon supply in North America, Production and pressure transient analysis of tight oil reservoirs is one of the most difficult problems facing a reservoir researcher because of the extreme complexity inherent in tight formations, To produce oil and gas commercially from tight formations, naturally completed (open-holed) or cased horizontal wells with multi-stage hydraulic fractures are the most popular implementation for completion, and such kind of application is expected to create a complex sequence of flow regimes (Chen and Raghavan, 1997; Clarkson and Pederson, 2010). The proper analysis and identification of presence of flow regimes and sequence of emerging flow regimes are essential for obtaining efficient information about hydraulic fracturing optimization and the tight formation characterization.
This paper provides a detailed discussion of numerical method of pressure transient and rate responses for hydraulically fractured horizontal wells in tight formation and compared with analytical (semi-analytical) methods based on the Bakken and Viking Formation in Western Saskatchewan. For Numerical simulated pressure transient responses, a naturally-completed (open-hole) and cased horizontal well with multiple transverse hydraulic fractures in a homogeneous or a sizable natural fracture system are considered. Numerical method for pressure and rate transient analysis is generated by employing a commercial reservoir simulator, CMG IMEX, a 3D finite-difference reservoir simulation package which is widely and popularly accepted by petroleum industry. As noted by many findings, it is shown that fully-filled and regional natural fractures would display various pressure transient characteristics and, hence, considerably affects well production performance. In addition, these conductive, interconnected natural fractures dominate the pressure transient performances of horizontal wells in tight formations even with the presence of hydraulic fractures. Additionally, the simulation runs also indicate that if the reservoir is naturally fractured to some extent, hydraulic fracturing stimulation might not improve productivity significantly, unless a large amount of hydraulic fractures and infinite conductivities can be achieved. To demonstrate the feasibility of numerical simulation models, there is a representative contrast between numerical and analytical (semi-analytical) methods. To demonstrate the feasibility of numerical simulation models, there is a representative contrast between numerical and analytical (semi-analytical) methods.
Microseismic Mapping Improves Understanding of a Complex Reservoir: A Case Study in a Southern Sichuan Shale Gas Field
Authors: Wang Yang , Zheng Guangjie , Wood Kevin , Xiao Yongjun , Yang Yang , Zhao Hao , Miao Yun 
Published: August 2016

Abstract
The Weiyuan-Changning shale gas play is one of the most prolific exploration and development targets in China. This paper discusses a case study from a southern Sichuan shale gas field, expanding on the challenges encountered during exploitation of this reservoir, such as complex stratigraphy. Solutions are proposed based on examples of successful microseismic data application, highlighting potential necessary considerations when making project design decisions in such complex geological zones, such as the southern Sichuan basin.
Located in the southern Sichuan basin at the intersection of two major anticlines, the primary pay zone within the Changning is the Longmaxi. Because hydraulic fracture stimulation in this complex stratigraphy can be technically challenging, determining the created fracture geometries is crucial to evaluating the effectiveness of a stimulation application. Downhole microseismic fracture mapping was identified early during the development of this play as a solution to understanding the mechanics and results of subsurface stimulation. This technology was used to evaluate the hydraulic fracturing of three Ning201 horizontal gas wells in the Longmaxi.
Microseismic data acquisition in the Changning shale proved to be successful, as microseisms were detected at distances in excess of 1800 m from the Ning201 fracture treatments. Based on these data, a large fault to the west of the treatment wells significantly influenced fracture geometry, though not to the extent expected. However, crosscutting minor natural fractures that were activated during injection might have led to casing failure in one of the wells. These fractures, particularly natural fractures running parallel to the direction of maximum principal stress, should be considered when making project design decisions in complex geological zones, such as the southern Sichuan basin.
This paper provides an integrated analysis of a Changning hydraulic fracturing project based on microseismic data, previous completions in the area, and new information. This knowledge can be applied to help optimize future development of the Changning.
La ludopatía: revisión y análisis hacia un modelo integral
Authors: Muñoz Londoño Yein Alexandra 
Published: August 2016

En el artículo se describe la Ludopatía, partiendo de la premisa de la Organización Mundial de la Salud, donde se considera como una enfermedad; además se generan interrogantes sobre las formas de abordar e intervenir esta adicción comportamental, realizando un acercamiento a los modelos cognitivo conductual, farmacológico y prevención de recaídas; se realizó una búsqueda exhaustiva del fenómeno en diferentes bases de datos científi cas, electrónicas y también en documentos físicos como libros y revistas, citando entre otros autores expertos en el tema como Domínguez, Villoria, Bisso, Echeburúa. Esto permitió: una mejor comprensión de la ludopatía, la evidencia de falencias en los factores de protección para tratarla, la necesidad de abordar al ser humano de manera integral, el respeto por las diferencias de género y el establecimiento de objetivos terapéuticos acordes con la complejidad de la adicción.
MAPEAMENTO TECNOLÓGICO COM PATENTES RELACIONADAS À BIOMASSA E AO BIODIESEL
Authors: Da Cruz Cleide Ane Barbosa , Almeida Paixão Ana Eleonora 
Published: August 2016

A busca por novas tecnologias vem proporcionando o surgimento de fontes de energia renováveis, como a biomassa e um dos seus derivados, o biodiesel. Por isso, o objetivo deste trabalho foi realizar um mapeamento tecnológico com patentes relacionadas à biomassa e ao biodiesel, analisando a evolução dos depósitos de patentes. O levantamento dos depósitos de patentes foi realizado na base Espacenet, associando os termos biomass and biodiesel, tendo retornado 302 documentos; todavia, apenas 212 foram disponibilizados pela base para análise. Notou-se a existência de depósitos de 2005 a 2015, sendo que o ano de 2013 apresentou o maior número, 40; porém, em 2015, houve uma queda drástica com apenas oito depósitos. A China foi o país com mais depósitos de patentes relacionadas à biomassa e ao biodiesel. E analisando o código de classificação internacional, observa-se que a classificação C12P 7/64 foi a mais presente nos depósitos efetuados. A maioria dos depositantes, 38%, é inventor independente, e os inventores Patrick G. Hatcher e Sanqiang Gong foram os que apresentaram elevada quantidade de depósitos relacionados às palavras-chave utilizadas na pesquisa. Além disso, percebeu-se que ainda é necessário maior incentivo e investimento em parcerias entre Universidades e empresa para que mais pesquisas possam ser feitas sobre biomassa e biodiesel.
Teljesítménymenedzsment innovációja egy könnyűipari középvállalkozásnál /szervezeti teljesítmény növelése egy új motivációs rendszerrel/
Authors: Török László 
Published: August 2016

Egy vállalkozás menedzsmentjének stratégiai célkitűzései megvalósításához folyamatosan figyelemmel kell kísérnie és koordinálnia azt, hogy az alkalmazottaknak mit kell tennie a kitűzött célok elérése érdekében. Ebben a tevékenységében a cégvezetésnek időnként és esetenként korrekciókat kell végrehajtania az alkalmazottak végzett munkájában és motivációiban. A dolgozat egy, a versenyszférában tevékenykedő, könnyűipari középvállalkozás esettanulmányán keresztül mutatja be azt, hogy a cégvezetés milyen új motivációs rendszert vezetett be a vállalkozásnál annak érdekében, hogy a vállalati teljesítményrangsorban hátul lévők produktuma növekedjen, és egyre inkább megközelítse a vállalati átlagos dolgozói teljesítmény értékeket. Azt, hogy a teljesítmény rangsorban hátul lévők kibocsátását növelni szükséges, a menedzsmentnek az a felismerése váltotta ki, hogy az átlag alatt teljesítők – alacsony kibocsátásuk ellenére – ugyan akkora álló- és forgótőkét kötnek le, mint az átlag felett teljesítők. A teljesítményrendszer keretein belül a normákon nyugvó követelményrendszert egészítette ki a cégvezetés úgy, hogy az szolgálta a munkavállalók hatékonyabb munkavégzését, amellett, hogy megerősítette őket szakértelmükben és a társasággal szembeni lojalitásukban. A teljesítménymenedzsment innovációjának eredményeként számottevően emelkedett a teljesítményrangsorban korábban hátul lévők kibocsátása, ami formálisan abban nyilvánult meg, hogy az egyénenkénti, havonta normákhoz mért teljesítmény százalékok szórása jelentősen csökkent, tartalmilag pedig a jelenség azt tükrözte, hogy megindult a teljesítményben leszakadó státusban lévők felzárkózása legalább a középmezőnybe soroltakhoz. Az egyéni teljesítmények rangsorban bekövetkezett „tömörülése” ez által hozzájárult azon vállalati stratégiai célkitűzés megvalósulásához, hogy a termelés átlagköltségei csökkenjenek, ezzel paralel a termelő tevékenység jövedelmezősége növekedjen.