bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards the Definitive VAT System – Update on the Implementation of the VAT Action Plan
Authors: Nykiel-Mateo Anna
Published: April 2019

The article provides an update on the implementation of the VAT Action Plan as regards the Commission’s proposal setting out the fundamental principles of the definitive single EU VAT area and a number of short-term measures to improve the functioning of the VAT system until the definitive regime has been implemented. It explains problems with the current transitional VAT arrangements, goes through the options for review as set out in the Impact Assessment accompanying the proposal and develops reasoning behind the preferred option. It then presents the contents of the proposal: cornerstones of the definitive system and the “quick fixes” relating to the call-off stock arrangements, VAT identification number, chain transactions and the proof of the intra-Community transport of the goods. It includes the explanation of the notion of the certified taxable person introduced by the proposal.
Pojęcie spółki kapitałowej i opodatkowanie przekształcenia spółek kapitałowych w spółki osobowe na kanwie podatku od czynności cywilnoprawnych
Authors: Gargul Michał
Published: April 2019

Przedmiotem artykułu jest analiza prawna zagadnień związanych z definiowaniem pojęcia spółki kapitałowej na kanwie podatku od czynności cywilnoprawnych oraz potencjalnym powstaniem obowiązku podatkowego w podatku od czynności cywilnoprawnych w sytuacji przekształcenia formy prawnej spółki kapitałowej w spółkę osobową.
Grunty rolne zajęte na prowadzenie działalności gospodarczej a podatek od nieruchomości
Authors: Michalak Alicja
Published: April 2019

W artykule omówione zostały kwestie związane z opodatkowaniem podatkiem od nieruchomości gruntów rolnych zajętych na prowadzenie działalności gospodarczej. Pojęcie gruntów zajętych na działalność gospodarczą nie jest uregulowane wprost w polskich przepisach. W artykule została więc przeprowadzona analiza orzecznictwa sądowego, wykładni systemowej oraz poglądów pojawiających się w doktrynie.
Ciudades seguras y sin violencias para las mujeres y las niñas, avances y retos de la ciudad de Medellín, Colombia
Authors: Montoya Ruiz Ana Milena , Correa Londoño Angela María
Published: April 2019

El siguiente artículo de investigación expone los resultados del Estudio exploratorio de la ciudad de Medellín para la implementación del Programa Ciudades Seguras Sin Violencia Hacia las Mujeres y Niñas Safe Cities y referentes explicativos para comprender las condiciones de inseguridad de las mujeres en los contextos urbanos. Se realizó un recorrido por las políticas públicas de la ciudad de Medellín y por las estrategias implementadas en el mundo en el marco de Safe Cities para mejorar la seguridad en las urbes, que fortalecen las estrategias de seguridad pública para el logro de la equidad de género en el territorio.
PROMENE U AKADEMSKOJ PROFESIJI I DRUŠTVENI ANGAŽMAN UNIVERZITETSKIH NASTAVNIKA
Authors: Grandić Radovan , Bosanac Maja
Published: April 2019

Otvorenost univerziteta prema zajednici postala je predmet brojnih kritika, ali isto tako i novih mogućnosti. Bez obzira na pristup od kojeg se polazi, otvorenost univerziteta prema zajednici nezaobilazan je deo funkcionisanja današnjih univerziteta. Pored nastave i istraživanja, kao osnovnih akademskih delatnosti, sve češće se govori i o trećoj misiji univerziteta koja se u najširem smislu može definisati kao interakcija univerziteta i zajednice, što velikim delom utiče i na obrazovne politike, kako na lokalnom, isto tako i globalnom nivou. Kao cilj rada postavlja se sagledavanje uloge koju univerzitetski nastavnici imaju kada je reč o društvenom angažmanu što predstavljamo kroz prikaz istraživanja iz prakse u Republici Srbiji realizovanog od strane Centra za obrazovne politike. Uz to, u analitičkom delu rada pažnja se usmerava i na reinterpretaciju akademske profesije, kao i predstavljanje različitih scenarija o budućnosti akademske profesije. Imajući u vidu da je ovo područje istraživanja nedovoljno proučeno u Republici Srbiji, u zaključku postavljamo i pitanja koja bi mogla da budu od značaja kako za pedagošku teoriju, isto tako i za pedagošku praksu.
UPOTREBA AFEKTIVNIH STRATEGIJA ZA UČENJE U NASTAVI POSLOVNOG ENGLESKOG JEZIKA
Authors: Kisin Nina
Published: April 2019

Ovaj rad  odnosi se na učestalost upotrebe afektivnih strategija u nastavi engleskog jezika. Afektivne strategije se koriste u manjoj meri, jer se učenici na početku učenja osećaju inhibirano da bi govorili o svojim strahovima i anksioznosti. Istraživanje je sprovedeno početkom letnjeg semestra školske 2014/2015. godine sa studentima Visoke poslovne škole iz Novog Sada. Istraživanje ima za cilj da dokaže da li i u kojoj meri studenti koriste afektivne strategije za učenje poslovnog engleskog jezika. Koristiće se kvantitativni metod obrade podataka dobijenih iz rezultata standardizovanog upitnika za strategije (ISUJ, eng. Strategy Inventory for Language Learning, SILL) autorke Rebeke Oksford (Oxford, 1990). Rezultati istraživanja pokazuju da se afektivne strategije koriste u najmanjoj meri. Ovaj rad ima za cilj propagiranje upotrebe afektivnih strategija u nastavi engleskog jezika od strane učenika, budući da se afektivne strategije koriste u manjoj meri.
Bahasa Melayu Palembang Mengadopsi Bahasa Arab Fusshah dalam Naskah Palembang Tahun 1842
Authors: Amin Abdul Azim
Published: April 2019

Guna memelihara dan mengembangkan bahasa Melayu, menuju tercapainya mimpi besar membangun peradaban Islam Melayu Nusantara, maka perlu menggali bahasa Melayu yang mendasari bahasa Indonesia sebelum Sumpah Pemuda 28 Oktober 1928 dan yang dipakai sebagai lingua franca selama berabad-abad[1] sebelumnya di seluruh kawasan Nusantara. Penelitian ini menggunakan metode penelitian kualitatif dengan mengutamakan penjelasan, uraian, dan analisa terhadap suatu peristiwa atau proses kegiatan  termasuk terhadap dokumentasi. Dalam penelitian ini menggunakan Naskah yang ditulis pada tahun 1842 berjudul “’Athiyatu r-Rahman fi Bayani Qowa’idi l-Iman” oleh   Kemas Muhammad Azhari bin Abdullah bin Ahmad Alfalimbani (1811-1874) di kota Makkah dengan huruf dan angka Jawi. Dalam naskah cetakan Makkah secara jelas disebutkannya bahasa Melayu Palembang yang digunakan dalam mengarang kitabnya tersebut. Bahasa Melayu Palembang, sebagaimana bahasa Melayu lainnya, pada awalnya merupakan bahasa Isyarat, dan berkembang sebagai Lisan, dan bahasa Tulis. Bahasa Melayu Palembang termasuk sebagai bahasa persatuan pada masa itu, bahkan hingga kini, terutama dalam mempersatukan beragam bahasa suku di Sumatera Selatan dan daerah sekitarnya, yang dipakai dalam pergaulan atau  hubungan antara suku-suku bangsa yang ada di negara tersebut, seperti di Nusantara. Dalam menuliskan bahasa Melayu Palembang ini, hampir semua huruf Arab dipinjam, baik untuk menuliskan bahasa Melayu Palembang itu sendiri maupun konsep ajaran agama Islam.

 

[1]Hasan Alwi dan Dendy Sugono, Politik Bahasa, BP2B, Kemendikbud, Jakarta, 2011: 5.
Kompetensi Qira’ah Naskah Arab Pada Mahasiswa Non Pesantren di Program Studi Bahasa dan Sastra Arab
Authors: Albab Ulil
Published: April 2019

Tujuan penelitian ini adalah memetakan kompetensi qiraah mahasiswa non pesantren di Program studi Bahasa dan Sastra Arab dalam membaca naskah Arab? Bagaimana pula skor kompetensi mahasiswa non pesantren tersebut dalam membaca naskah Arab? Permasalahan ini akan peneliti bahas dengan menggunakan jenis penelitian kuantitatif. Penelitian kuantitatif adalah penelitian yang berangkat dari teori ke lapangan kemudian kembali ke teori untuk diuji kebenarannya.Adapun sampel dalam penelitian ini adalah menggunakan teknik penarikan purposive sampling. Teknik penarikan sampel ini dipilih berdasarkan karakteristik penelitian, yaitu mahasiswa non pesantren pada program studi Bahasa dan Sastra Arab UIN Raden Fatah Palembang. Penelitian ini membuktikan bahwa kemampuan membaca teks bahasa Arab pada tahap penyimpulan teks mahasiswa lulusan non pesantren masuk dalam kategori rendah. Hal ini salah satunya dipengaruhi oleh pengalaman dan latar belakang sekolah mahasiswa tersebut sebelum masuk ke perguruan tinggi Islam. Latar belakang dan pengalaman ini sangat penting bagi mahasiswa yang ingin studi lanjut ke perguruan tinggi pada program studi bahasa dan sastra Arab, agar bisa mengikuti proses belajar mengajar secara cepat dan lulusan yang berkualitas. Kemudian perolehan skor kemampuan membaca teks bahasa Arab pada tahap menyimpulkan teks pada tes pertama skor terendah adalah 10, skor terendah pada tes kedua adalah 20. Kemudian skor rata-rata pada tes pertama adalah 55,6 dan pada tes kedua 46,5. Skor nilai tengah pada tes pertama adalah 60, dan pada tes kedua 45. Skor nilai paling banyak pada tes pertama adalah 40,50, dan 60, dan pada tes kedua 30,40,50.
Desarrollo regional y emprendimiento: evidencia para Colombia
Authors: Duran Peralta Julian
Published: April 2019

Antecedentes: la asociación entre desarrollo y emprendimiento ha sido abordada en múltiples trabajos como una relación unidireccional, ya sea que se intente explicar el desarrollo a partir del emprendimiento o viceversa. Por tal motivo, el objetivo fundamental del artículo es avanzar un poco más y evaluar para Colombia el vínculo entre el desarrollo de las regiones y su grado de emprendimiento como una relación endógena o de retroalimentación.Métodos: se toman como indicadores del nivel de desarrollo regional el pib per cápita y el volumen de ocupación, mientras que como índice de emprendimiento se utiliza la tasa de empleadores y trabajadores cuenta propia con alto nivel de capital humano. Posteriormente, se contrastan modelos de ecuaciones simultáneas por el método de mínimos cuadrados en tres etapas (MC3E), en el que las variables explicadas son el desarrollo regional y el grado de emprendimiento.Resultados: existe evidencia de una relación endógena y positiva entre ambos factores; el emprendimiento incide positivamente en el desarrollo regional, y a su vez, el nivel de desarrollo regional afecta positivamente el emprendimiento.Conclusiones: además de las fuentes tradicionales del desarrollo consideradas en este ejercicio, el emprendimiento constituye un componente fundamental en el momento de planear el desarrollo regional. Elevar la participación del autoempleo asociado con las categorías ocupacionales de empleadores y cuenta propia con alto nivel de educación es una estrategia que, según los resultados de este artículo, permite generar una dinámica de retroalimentación positiva con la actividad económica.
Capital social y asimilación ocupacional de los migrantes internos en Perú
Authors: Campos Ugaz Daniela Mía
Published: April 2019

La migración interna es uno de los fenómenos que más ha configurado la población, la economía y la geografía peruanas en el último siglo. En este estudio se parte de la premisa de que la migración es un proceso complejo que puede tener efectos diferenciados sobre las personas dependiendo de una diversidad de factores. Esto cobra particular relevancia si se busca evaluar el desempeño de los migrantes en un mercado rígido como el laboral. Así, se plantean mecanismos como la contribución de la sociedad civil y de otras disposiciones institucionales que pueden proveer una gama de beneficios y servicios a sus miembros cuando los mercados no son perfectos, como en el caso de las elecciones ocupacionales. Por lo anterior, el presente trabajo muestra cómo el capital social interviene en la asimilación ocupacional de los migrantes internos en Perú. Para ello, se presenta un modelo teórico en el cual se plantea que dos tipos de capital social (étnico y adquirido) pueden ofrecer distintos tipos de servicios, dependiendo del nivel de complementariedad de este con el nivel educativo y con el tiempo que el migrante lleve en su lugar de destino (migrantes recientes y establecidos). A partir de la Encuesta Nacional de Hogares (2014) y de una estimación mediante logit multinomial, se encuentra que el capital social étnico incrementa la probabilidad de desempeñar una ocupación elemental únicamente para los migrantes recientes y que el capital social adquirido incrementa la probabilidad de desempeñar una ocupación de alta calificación para los migrantes establecidos.
Characteristic volatile compounds of Monastrell wines
Authors: Rita Szikszai Andrea
Published: April 2019

Seventy-five percent of the red wines of the Protected Designation of Origin (PDO) Alicante are based on Monastrell grapes. The wine aroma is one of the most important characteristics linked to the quality and consumers’ preferences. Scopus database was used to gather information about the concentrations ranges of the main volatile compounds present in the Monastrell red wines, with their aromatic descriptions and their detection and/or recognition thresholds. Seventeen volatile compounds were identified as those having a significant contribution to this red wine aroma. However, it is important to indicate that there is a need to continue reviewing critically the threshold values (detection and/or recognition) of the main volatile compounds with a "potentially" significant contribution to the odor/aroma/flavor of the Monastrell wines. This information will be essential in preparing reference materials for trained sensory panels calibration for descriptive sensory evaluation of wines.
Mejora del rendimiento de equipos de aire acondicionado tipo Split mediante el uso del condensado para enfriamiento evaporativo de la unidad exterior
Authors: Velázquez Marín Alfredo
Published: April 2019

El crecimiento sustancial en la industria de refrigeración y aire acondicionado tiene un impacto significativo en el consumo de energía. Existe una necesidad urgente de desarrollar tecnologías rentables y mejorar la eficiencia de los sistemas de enfriamiento. La presión del condensador es uno de los parámetros críticos en la operación eficiente de sistemas de refrigeración y aire acondicionado. El condensador enfriado por evaporación de agua ha sido una de las soluciones en la búsqueda del uso eficiente de millones de sistemas de refrigeración en todo el mundo. Los brotes de Legionella sp. han condicionado su uso y ha dado lugar al desarrollo de nuevos equipos. En esta revisión del estado del arte se analizarán diferentes sistemas de condensación, los diseños que los investigadores han presentado dirigidos a su utilización en equipos del sector comercial y residencial y, en último lugar, los estudios publicados sobre el uso del condensado para el enfriamiento.
Batch Drilling of Two Exploration Wells from a Jack Up Rig by Modifying Conductor Deck Results in Substantial Savings
Authors: Sharma Deepak , Golwalkar Anirudh , Singh Ankit , Doodraj Sunil , Vermani Sanjeev
Published: April 2019

The scope of the paper is to explain, at first, the modification done to the conductor deck of a jack up rig in order to drill two exploration wells from one open water location, offshore of east coast of India. Further the paper explains the process of batch drilling used in the campaign and how the combination of the two resulted in substantial cost saving.

For the modification in conductor deck, feasibilities were checked for each rig during the tender evaluation stage to create an additional slot in the conductor deck while maintaining the conductor tensioning requirement on both slots. The conductor deck of the finalized rig was fabricated accordingly. The wells were planned, with one being vertical and the other deviated, to two different targets. The conductors on both wells were batch set. Similarly, the surface hole sections on both the wells were batch drilled & cased. Then drilling of the production holes, logging & abandonment were carried out batchwise.

As a result of batch drilling, the time in installation & removal of wellhead was completely saved as it was carried out offline. Similarly the time in installation & removal of BOP was reduced to half as it was done only once. There were other instances as well, described in detail in the paper, which led to a cumulative savings of 29.86 days against total planned time of 96.51 days during the complete drilling campaign, apart from saving days & associated weather risk by eliminating one complete rig move. Much of the time saved above was due to the batch drilling which was a result of the conductor deck modification and also due to the well design changes based on actual well conditions, which are also explained briefly in the paper.

As industry is recovering from a steep decline in drilling activity, it is only incremental innovations & even more so, a combination of existing innovations like the one showcased in this paper, which can lead to a positive economics for E&P companies, especially for exploration drilling projects.
Evolution of High Rate Water Pack Pumping Methodology During Sand Control Campaign: A Case Study from India
Authors: Bordeori Krishna , Gupta Vaibhav , Sharma Lovely , Narayan Shashank , Talukdar Dhurba , Lama Tshering
Published: April 2019

Cased hole gravel pack (CHGP) is the most popular method for controlling production of formation sand in oil or gas cased hole wells. CHGP involves the packing of screen and casing annulus, and perforations to inhibit production of formation sand. Success of a CHGP depends on various factors such as perforation packing, cleanliness of completion brine, perforation strategy and minimizing drawdown. Quality of perforation packing aids in minimizing drawdown of gravel pack completions. This led to popularization of high-rate water packs (HRWPs), an evolved sand control method for cased hole wells. HRWPs involve pumping above fracture extension rate and placing gravels outside casing into the critical matrix. This paper discusses maturation process in design, execution, and evaluation methodology devised from a campaign of 16 HRWPs, which included two formation breakdown acid injections, one slim hole completion, two re-stresses and one top-off.

Naharkatiya fields of Oil India Limited, in Assam-Arakan basin are characterized with high degrees of unconsolidated formation sand. Elements of heterogeneity like formation sand ingression rate, PSD, mineralogy and well-profile in these two fields, where most of the HRWP treatments were executed, demanded case-specific pre-gravel-pack workover operations. Installation of screens and pumping of HRWP treatment presented many challenges, such as formation sand ingression, high circulation pressures, uneven slack/pull weights and issues in tool operations. All these challenges were tackled in unique ways and successful HRWP treatments were completed. A holistic approach was developed towards execution of a High Rate Water Pack treatment, by analyzing all interlinked elements such as perforations, cores, cement bond, reservoir saturation, water cut and offset well history. Post-treatment evaluation of HRWPs using bottomhole gauges identified a sequence of downhole events and potential issues during execution phase. Correlating each new HRWP candidate with learnings from previous ones allowed the operator to better plan workover steps towards execution of the sand control treatment. Contingency plans were devised to tackle issues learned from previous wells, and many were successfully tested in the campaign. Production rates and choke strategies were optimized by analysis of offset wells.

This paper presents data analysis of wells while correlating with their offsets. Post-treatment analysis has been discussed and correlations between suspected issues during execution with signatures in bottom-hole gauge data have been presented. Recommendation are further provided for drilling and completion operations. Evolution in design and execution process for case wells has been presented, which can be used as a reference literature for designing case specific sand control treatment program.
Digitalization of Formation Damage Candidate Screening Workflow Improves Process Efficiency
Authors: Gupta Anish , Narayanan Puveneshwari , Trjangganung Kukuh , Mohd Jeffry Suzanna Juyanty , Tan Boon Choon , Awang M Rais , Badawy Khaled , Yip Pui Mun
Published: April 2019

A matrix stimulation candidate screening workflow was developed with the objective to reduce the time and effort in identifying under-performing wells. The workflow was initially tested manually for few fields followed by inclusion in Integrated Operation for an automated screening of wells with suspected formation damage. Analysis done in three fields for stimulation candidate selection will be displayed with actual statistics.

The main aim of the work was to digitalize the selection of non-performing candidates rather than manually looking into performance of each well. A concept of Formation Damage Indicator (FDI) was combined with Heterogeneity Index (HI) of the formations to screen out the candidates. Separate database sets of Reservoir engineering, Petrophysicist and Production was integrated with suitable programming algorithms to come up with first set of screened wells evaluating well production performances, FDI and HI trends up to over the last 30 years. The shortlisted candidates were further screened on the basis of practical approach such as gas lift optimization, production trending, OWC-GOC contacts, well integrity and well history to come up with second round of screened candidates. The final candidates were analyzed further using nodal analysis models for skin evaluation and expected gain to come up with type of formation damage and expected remedial solution.

For fields A and D with a total of 210 strings each, the initial FDI and HI screening resulted in 70 and 120 strings being shortlisted, respectively. This was followed by a second round of screening with 25 and 35 strings being further shortlisted as stimulation candidates, respectively. Nodal analysis models indicated presence of high skin in 90% of the selected wells indicating a very good efficiency and function-test of the workflow. In addition to selection of the candidates, the identification of formation damage type was compiled on an asset-wise basis rather than field basis which helped in more efficient planning of remedial treatments using a multiple well campaign approach to optimize huge amount of cost. The entire screening process was done in one month which was earlier a herculean task of almost one year and much more man-hours. With effective manual testing of the workflow in two major fields, workflow was included in Integrated Operations for future automation to conduct the same task in minutes rather than months.

With this digitalized unique workflow, the selection of under-performing wells due to formation damage is now a one click exercise and a dynamic data. This workflow can be easily operated by any engineer to increase their operational efficiency for flow assurance issues saving tons of cost and time.
Enhancing Reservoir Characterization by Calibrating 3D Reservoir Model with Inter-Well Data in 2D Space
Authors: Mishra Shubham , Shrivastava Chandramani , Ojha Aditya , Miotti Fabio
Published: April 2019

Until recently, reservoir characterization methods in the industry were limited to use of seismic technologies in exploration of oil and gas and had a very constrained role in production and development. In the past, using characterization for development fields was considered a very perilous task. Technological advancements and the risk-averse mindset have significantly expanded the application of reservoir characterization. Today, reservoir characterization is the basis of any development plans made for a commercial field.

Development of 3D reservoir modeling techniques to generate field development plans (FDPs) marked a step-change in reservoir characterization methods. Introduction of geostatistics and numerical simulation made it possible to build precise models to generate realistic field development scenarios. This is the state-of-the-art seismic-to-simulation method of reservoir characterization used in FDPs today. However, the struggle to estimate reservoir properties spatially away from the well continues.

Surface seismic data provide excellent areal coverage but do not provide the vertical resolution required for a fine-scale reservoir model. Geostatistical methods reduce the uncertainty in spatial distribution of petrophysical properties from pseudo-point supports (wells) but are not calibrated spatially between the wells. Correspondingly, the fluid saturation distribution and the parameters used in dynamically calculating the same during numerical simulation are not calibrated in the interwell space.

This paper details necessary data acquisitions and methods of calibration of 3D reservoir model to reduce uncertainty in the interwell space. The data acquisition methods have been available for some time, but have rarely been electronically incorporated in the 3D reservoir model and have been largely used to analytically guide the modeling and its inferences. A logical way of interpreting the results of acquisitions and calibrating the 3D reservoir model cell-by-cell is detailed in this paper.
Modelling of Critical Parameters of Oil Spill
Authors: Samudre Rahul , Khatri Shubhada , Sakpal Nilesh , Patwardhan Samarth
Published: April 2019

Oil spill is considered as one of the biggest ecological disasters due to the scale of the impact it has, on the ecosystem being affected. Offshore oil spills have proven to be a global concern for marine ecosystem and appropriate measures for their control, prevention and removal of contaminants must be considered as top priority.

This paper entails a detailed study of the various available oil spill clean-up techniques and looks at its advantages and limitations. Further, a grading system for all these methods based on oil type, treatment volume, weather conditions, complexity, water turbulence, time required for results, their environmental impact, cost and efficiency is prepared.

In the case of a spill, oil dispersion behavior acts differently for different kind of fluids on sea water depending on their properties, with the effect of turbulence being one of the critical factors. This paper also focuses on the study of different behavior of crude oil and gasoline on sea water using a commercially available CFD (computational fluid dynamics) tool which utilizes more accurate and relevant mathematical formulations. A multiphase oil spill model has been developed to simulate dispersion of oil spill. A consistent Eulerian approach and Navier-Stokes equations is applied across the model, and the diffusion is employed to simulate oil dynamics in the water. The used Multiphase Oil Spill Model takes advantage of recent developments in the areas of CFD.
Learning and Development from the World’s First Operating Subsea Compression System
Authors: Vesterkjaer Rune , Jorgensen Stein
Published: April 2019

After years of development, qualification and engineering, subsea compression technology is now a proven solution to increase the recovery factor for offshore gas developments. The first subsea compression system was installed at the Aasgard field in the Norwegian Sea, which was started up successfully on the 17th. of September 2015. This project represents an important milestone for the oil and gas industry, as apart from representing the successful developments of new subsea processing technologies, subsea compression also proves itself a viable alternative field development option to oil and gas operators.

The experience from Aasgard enables tomorrow’s subsea compression solutions. The basis is increased field recovery by subsea compression. In addition it opens for wells stream and deep water applications, as well as CO2 EOR.

This paper aims to share Aker Solutions’ experience on Aasgard Subsea Compression project, from the design and the project execution phases up to the operational phase, highlighting the key learnings from more than 50 000 hours of successful subsea operation.

In addition, the paper will also describe the ongoing development activities to optimize the compression system delivered for Aasgard, with particular focus on increased field recovery and unit size and weight optimization without requiring qualification activities of new technologies. This new generation of subsea compression system will extend the applicability of this technology to a much wider range of fields and offshore regions.
Electrical Interference-Emerging Threat to Pipeline
Authors: Gangula Venkateshwar reddy , Bera Kamlesh
Published: April 2019

This paper covers the problem related to AC interferences on East West Gas Pipeline (EWPL) and the mitigation measures taken for reducing / eliminating the same.

AC interference was observed in Hyderabad region due to AC EHV Transmission lines crossing EWPL, three phase transformers and Single wire earth return (SWER) single phase transformers in the vicinity of pipeline. AC PSP voltage up to 80 Volts were observed on pipeline during night hours for which various mitigation measures were taken to bring down in acceptable range.

Similarly, there is possibility of high voltage surge at station facilities along the pipeline route due to vicinity of multiple structures, long pipeline length and having multiple conducting structures at MLV stations comprising of RTD’s, die-electric isolators, impulse Tubing for power gas and associated power gas and control equipment. Surge travel to such system can result in equipment failures. Various pro-active measures to mitigate such instances were adopted on pipeline system and are implemented successfully.

This paper illustrates the extent of the risk of corrosion, surge impact due to AC interference / surge and gives insight to various methods deployed for minimizing these risks in simple and most economical way. It also highlights the need for collaboration and operational coordination between the pipeline operators and state electricity boards to resolve such issues mutually & in most effective manner.
A Novel Cationic Polymer System That Improves Acid Diversion in Heterogeneous Carbonate Reservoirs
Authors: Sarmah Abhishek , Farid Ibrahim Ahmed , Nasr-El-Din Hisham , Jackson Jennifer
Published: April 2019

In-situ gelled acids have been used for acid diversion in heterogeneous carbonate reservoirs for more than two decades. Most of the gelled systems are based on an anionic polymer that has a cleaning problem after the acid treatments that leads to formation damage. This work evaluates a new cationic-polymer acid system with the self-breaking ability for the application as an acid divergent in carbonate reservoirs.

Experimental studies have been conducted to examine the rheological properties of the polymer-based acid systems. The apparent viscosities of the live and the partially neutralized acids at pH from 0 to 5 were measured against the shear rate (0 to 1,000 s-1). The impact of salinity and temperature (80 to 250°F) on the rheological properties of the acid system was also studied. The viscoelastic properties of the gelled acid system were evaluated using an oscillatory rheometer. Dynamic sweep tests were used to determine the elastic (G’) and viscous modulus (G") of the system. Single coreflood experiments were conducted on Indiana limestone cores to study the nature of diversion caused by the polymer-acid system. The impact of permeability contrast on the process of diversion was investigated by conducting dual coreflood experiments on Indiana limestone cores which had a permeability contrast of 1.5-20. CT scans were conducted to study the propagation of wormhole post acid injection for both single and dual corefloods.

The live acid system displayed a non-Newtonian shear-thinning behavior with the viscosity declining with temperature. For 5 wt% HCl and 20 gpt polymer content at 10 s-1, the viscosity decreased from 230 to 40 cp with temperature increasing from 88 to 250°F. Acid spending tests demonstrated that the acid generated a gel with a significant improvement in viscosity to 260 cp (at 250°F and 10 s-1) after it reached a pH of 2. The highly viscous gel plugged the wormhole and forced the acid that followed to the next higher permeability zone. The viscosity of gel continued to increase until it broke down to 69 cp (at 250°F and 10 s-1) at a pH of 4.8, which provides a self-breaking system and better cleaning. Coreflood studies indicated that the wormhole and the diversion process is dependent on the temperature and the flow rate. There was no indication of any damage caused by the system. The injected acid volume to breakthrough (PVBT) decreased from 2.2 to 1.4 when the temperature increased from 150 to 250°F.

The strong elastic nature of the gel (G’= 3.976 Pa at 1 Hz) formed by the partially neutralized acid system proves its suitability as a candidate for use as a diverting agent. This novel acid-polymer system has significant promise for usage in acid diversion to improve stimulation of carbonate reservoirs.
Effect of Fluid Expansion and Clay Diagenesis on Shale Reservoirs
Authors: Dutta Jayanta , Sahoo Ajit Kumar , Srivastava Mukul , Vishal Vikram
Published: April 2019

Shale plays are anisotropic in terms of their reservoir quality which gets reflected in their productivity. Reservoir qualities like organic richness, thermal maturity, hydrocarbon saturation, the volume of clay, brittleness and pressure affect the productivity of the shale plays. In general, the volume of clay has a negative relationship whereas other parameters listed above have a positive relationship with production. In our study area, we found the deepest wells despite having better rock quality; do not perform like nearby shallower wells. The objective of this study is to understand the not so obvious reason behind underperformance of these deepest wells.

Since the wells are located at a deeper depth and the reservoir temperature is high (90 to 135°C), so we studied the area from clay diagenesis and fluid expansion perspective. We have reviewed the imprints of clay diagenesis with the help of XRD data and core integrated multi min processed wireline logs. We observed an increasing trend of illite, chlorite towards the deeper part of the reservoir along with a decreasing trend of smectite in the same direction which indicates a higher degree of clay diagenesis. Fluid expansion study is carried out with the help of total organic carbon and hydrocarbon saturation. This study indicated a higher degree of fluid expansion (TOC to hydrocarbon generation) in the deepest part.

Subsequently, 1D pore pressure, stress and rock mechanical modeling is carried out to evaluate the effect of a higher degree of diagenesis and fluid expansion on geomechanical parameters (pore pressure, stress and brittleness). 1D modeling reveals that the deeper wells have abnormal pressure, stress and low brittleness, which is primarily due to extra pressure contribution from fluid expansion and clay diagenesis apart from the compaction disequilibrium process. This abnormal stress and reduction in brittlness likely to have created challenges for the applied hydrofrac job in the deepest part resulting to narrow frac geometry. Comparison of hydraulic fracture modeling between a shallow and the deepest wells reveal that the hydraulic fracture geometry in the deepest well is narrower than the shallower well. So we came to the conclusion that the deepest wells are underperforming than the shallower wells despite of their better rock quality due to ineffective fracturing and comparatively narrower fracture geometry.

The impact of clay diagenesis and fluid expansion in shale productivity has not been studied widely. Though many authors have extensively studied the impact of clay diagenesis on permeability and pore pressure, the integration of shale well production is rarely attempted. This work will help the operators to better analyze and understand their shale reservoir from clay diagenesis and fluid expansion point of view before planning the hydrofrac jobs.
Novel Techniques for the Evaluation of Hydrogen Sulfide Scavenger Performance and By-Product Stability
Authors: Patel Niley , Rafferty Andrew , Stewart-Liddon Christine , Hammonds Paul , Graham Gordon M. , Maskell Phillip , Frigo Dario M.
Published: April 2019

A technique has been developed to allow for the comparison of scavenging rates and scavenging capacity of different hydrogen sulphide scavengers by continuously measuring the hydrogen sulphide concentration in the gas phase of a multiphase system. In addition, the stability of the scavenger reaction products has also been investigated.

The methodology to assess the performance of the hydrogen sulphide scavenger is described. The scavenging rates of the hydrogen sulphide scavenger are compared by the contact time required to reduce the initial hydrogen sulphide concentration to a pre-determined value. In addition, the scavenging capacity of the scavengers can be calculated by recording the gaseous hydrogen sulphide concentration once the reaction has been allowed to run to completion. Finally, the stability of the scavengers and their reaction products, including carbon disulphide, are determined by treating a solution of the scavenger with excess hydrogen sulphide.

It is known that hydrogen sulphide scavengers have the potential to form reaction products that can foul the refining process. More recently, it has been identified that carbon disulphide may be produced during the scavenging reaction of some commonly used triazine based chemistries, driving a desire to identify alternative products. These works describe a new method which is capable of differentiating between the hydrogen sulfide scavenging performance of different chemistries. It also allowed for the scavengers to be differentiated with respect to the formation of both solid and oil soluble by-products, with the presence / increase in carbon disulphide analysed by gas chromatography. By doing this, the method allows for improved scavenger selection on the basis of performance, compatibility and cost.

This work presents a novel method for the assessment of relative reaction rates and scavenging capacity of hydrogen sulphide scavengers. In doing so, it allows the evaluation of cost performance and suitability of different treatments and scavenger chemistries to be evaluated. Additionally, the likelihood of a scavenger chemistry fouling the refining process due to the production of reaction by-products can be investigated.
Addressing Issue of Hydrate Inhibition during Start-Up of a Deepwater Field - A Case Study
Authors: Hazarika Simanta , Rathod P. Ramulu , Burla Ravishankar , Das Gour Chandra , Rao Bkvrl , Deuri Budhin
Published: April 2019

Subsea flow lines in deep water are typically exposed to high pressure and low temperature conditions which can create problems due to formation of gas hydrate. The gas hydrate formed can plug the flow lines causing not only loss of production, but may also create severe safety and environmental hazard. Moreover, dissociation of these plugs may take weeks or even months. Assessment of the hydrate formation potential during both steady is therefore an essential part of field development studies.

The paper presents a case study of a gas field located in KG basin of India which was brought on production in 2018. The objective of the study was to assist the on-site team on issues related to hydrate inhibition during ongoing initial start-up operation and assess the arrival time of rich MEG in the onshore plant in view of turn down flow conditions during commissioning.

The study also demonstrates how the transient simulations helped to monitor progress, identify and respond quickly to address the challenges during initial start-up operation of the deepwater gas field in Indian east coast. It emphasizes the need for accurate estimation of rich MEG arrival time and the minimum required gas flow rate from the subsea wells to ensure timely return of rich MEG to the onshore plant in order to avoid disruption in hydrate inhibition in the subsea system.
Evaluation of Zwitterionic Surfactant for Applicability in Enhanced Oil Recovery
Authors: Kumar Amit , Mandal Ajay
Published: April 2019

The objectives of the present study are to evaluate a zwitterionic surfactant for applicability in EOR. The surfactant was tested in terms of its salt tolerance, thermal stability, interfacial reduction capability, wettability alteration and resistance to adsorption. The effect of salinity and alkalinity was also tested on the above stated physico-chemical properties of the surfactant.

The salt tolerance of the surfactant was tested by testing for precipitation of surfactant solution with increasing salinity at 30 °C and 80 °C. The thermal stability of the surfactant was tested by TGA testing. The interfacial tension of the crude oil and surfactant solution with varying surfactant concentration, salinity and alkalinity was tested by spinning drop technique. The wettability alteration by surfactant solution was tested by measuring contact angle on an oil wet sample. The adsorption study was done by measuring the concentration of surfactant after its solution was exposed to adsorption on crushed rock sample.

The surfactant had salt tolerance of 20% salinity. The surfactant was found stable to 130 °C as per TGA curve. The interfacial tension (IFT) was reduced to ultralow value by surfactant solution for concentration at and above its critical micelle concentration. The presence of salt had minimal effect on the IFT reduction capability of the surfactant solution. Presence of alkali had synergetic effect on IFT reduction. The wettability of the oil wet sample was altered to preferentially water wet by surfactant. The loss of surfactant due to adsorption was found to be within recommenced range for applicability in EOR. These excellent physico-chemical properties of the zwitterionic surfactant suggest that it can be used in the mature oil fields for recovery of trapped oil.
Slot Recovery & Sidetracking Using Dual Casing-Exit Whipstock Technology in a Single Trip
Authors: Gupta Arpit , Thomas Emil , Tomar Gaurav , Rawat Ishita , Prakash Aditya , Golwalkar Anirudh , Vermani Sanjeev
Published: April 2019

In offshore platforms, with high well density, slot recovery technique is an efficient way to target new / un-swept avenues to boost the production levels in a mature field. This leads to utilization of an appreciable length of parent bore which is an advantage to the operators globally in terms of surface facility retention and associated rig time saved. This paper discusses an actual case-study wherein dual casing exit was achieved in an offshore platform well resulting in significant time and cost savings.

For the subject well the subsurface targets were quite far from the mother-bore, resulting in a plan to side-track the well at a shallow depth where double casing existed, i.e. 9-5/8″ × 13-3/8″. The options available were pilot milling and dual exit using whipstock. Unlike multi-casing exits, pilot milling is a time consuming method which requires multiple trips and involves large volume of metal swarf handling at surface. The CBL-VDL verified the presence of cement outside 9 5/8″ casing that further supported the case of dual casing exit operation. Consequently, associated risks were discussed and plans to mitigate the same were put in place.

Single-trip 8-1/2″ whipstock-milling system was used to cut a window suitable for running drilling BHAs, liner, and completion equipment. The 9-5/8″ × 13-3/8″ annulus was monitored during milling and FIT test to check for any pressure communications. For well control scenario, arrangements were made for connecting the annulus to the choke manifold to ensure a closed system and thereby have provision of circulating through choke in case of gas migration in the 9-5/8″ × 13-3/8″ annulus. The window milling operation was done using sea water & intermittent Hi-vis sweeps. The window was milled successfully in a "single trip", thereby saving considerable rig time. No excess drag or held-up was observed and gauge loss on mills when pulled out of the hole was negligible. Well integrity was intact with no pressure communication in the annulus. The job was a successful one that led to finishing the well within the planned time and thereby, led to timely release of the jack up rig before the onset of adverse weather conditions.

Multi-casing exit technology in two or three casing strings opens the multi-level advantages to well intervention techniques especially in situations where the wells are old with limited access due to presence of fish or other restrictions that makes the deeper section of the well non-usable. Such sections can be avoided by sidetracking at a shallow depth and also provides an opportunity to access targets that are quite far from the original mother-bore.
Prediction of Lost Circulation Prior to Drilling for Induced Fractures Formations Using Artificial Neural Networks
Authors: Alkinani Husam H. , Al-Hameedi Abo Taleb , Dunn-Norman Shari , Alkhamis Mohammed M. , Mutar Rusul A.
Published: April 2019

Lost circulation is a complicated problem to be predicted with conventional statistical tools. As the drilling environment is getting more complicated nowadays, more advanced techniques such as artificial neural networks (ANNs) are required to help to estimate mud losses prior to drilling. The aim of this work is to estimate mud losses for induced fractures formations prior to drilling to assist the drilling personnel in preparing remedies for this problem prior to entering the losses zone. Once the severity of losses is known, the key drilling parameters can be adjusted to avoid or at least mitigate losses as a proactive approach.

Lost circulation data were extracted from over 1500 wells drilled worldwide. The data were divided into three sets; training, validation, and testing datasets. 60% of the data are used for training, 20% for validation, and 20% for testing. Any ANN consists of the following layers, the input layer, hidden layer(s), and the output layer. A determination of the optimum number of hidden layers and the number of neurons in each hidden layer is required to have the best estimation, this is done using the mean square of error (MSE). A supervised ANNs was created for induced fractures formations. A decision was made to have one hidden layer in the network with ten neurons in the hidden layer. Since there are many training algorithms to choose from, it was necessary to choose the best algorithm for this specific data set. Ten different training algorithms were tested, the Levenberg-Marquardt (LM) algorithm was chosen since it gave the lowest MSE and it had the highest R-squared. The final results showed that the supervised ANN has the ability to predict lost circulation with an overall R-squared of 0.925 for induced fractures formations. This is a very good estimation that will help the drilling personnel prepare remedies before entering the losses zone as well as adjusting the key drilling parameters to avoid or at least mitigate losses as a proactive approach. This ANN can be used globally for any induced fractures formations that are suffering from the lost circulation problem to estimate mud losses.

As the demand for energy increases, the drilling process is becoming more challenging. Thus, more advanced tools such as ANNs are required to better tackle these problems. The ANN built in this paper can be adapted to commercial software that predicts lost circulation for any induced fractures formations globally.