bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Young Engineers in a Company Through Organization of Internal Competitions
Authors: Kurmankulov Alikhan , Ramatullayev Samat , Sidorov Dmitry 
Published: October 2020

Abstract
In this paper authors share an experience of one of many ways to foster professional development culture among young engineers through organization of an internal competitions. The competition was held among reservoir engineers working in different locations across the world with a purpose to accelerate and bring to a whole new level their knowledge about one of company flagship software products as well as to use it to solve tough real world industry challenges via application of latest technology and domain knowledge.
The competition was presented in a form of field optimization challenge using new high-fidelity reservoir simulator to give opportunity for everyone interested to learn and uncover simulator's broad and rich functionality. The challenge consisted of two optimization tasks targeting 1) recovery factor and 2) net present value (NPV). There were some field development constraints, such as drilling budget, availability of rig resources, surface facility capability, economic considerations – capital and operating expenditure. The model provided for this challenge represented a synthetic carbonate reservoir that has geological and petrophysical properties inspired by a real carbonate outcrop.
The duration of the challenge was one month. During this period participants tested different field development plan (FDP) scenarios and at the end submitted their solutions. The engagement level among young engineers and creative solutions presented are indicative of a success of this initiative. The competition not only allowed to apply their domain knowledge to tackle real field challenges but also propelled forward their knowledge on advanced features of the simulator.
Rich capabilities of the simulator allowed to implement complex operating logic to manage an asset along with getting hands-on experience designing and optimizing latest technologies such as intelligent completions. On top of that engineers learned to approach a problem from operator's point of view by optimizing capital and operating expenditure – finding a best spot for infill drilling, estimating optimal volume of fluid injection for pressure maintenance, dealing with water breakthrough in production wells and so on. The solutions were evaluated by an organizing committee in each category and winners received special awards. One of the authors of this paper had a privilege to be awarded the highest prize in "NPV optimization task".
Authors will share one many proven effective methods to develop young engineers within a company through engagement and interest to solve industry problems. Also, the paper will provide case studies from the challenge that may spark an interest in industry professionals in reservoir engineering domain along with some differentiating features of new high-fidelity reservoir simulator used in this competition.
Advanced Rod Pump Optimization Approach – Case Study
Authors: Sultabayev Arkhat 
Published: October 2020

Abstract
While most of the operators in Kazakhstan still rely on surface dynocards for rod pump diagnostic, this report shows the value of having pump (calculated) dynocards to obtain production insights. Thanks to mathematical calculations ("wave equation") a dynocard is cleared from all "system noises" and only what is happened at the pump is shown. Advantages of using downhole dynocard are discussed with real wells cases on several Kazakhstan mature fields.
Risk factors for Oil and Gas Workers on the Offshore Ice-Resistant Platform in the Caspian Sea
Authors: Korneeva Yana Aleksandrovna 
Published: October 2020

Abstract
The purpose of the study is to identify and describe uncomfortable factors and environmental conditions, as well as hazardous professional situations for fly-in-fly-out workers of an offshore oil platform in the Caspian Sea. The study was conducted on an ice-resistant offshore platform, the Caspian Sea, and was attended by 50 people (fly-in duration - 14 days). The research method is a questionnaire. The questionnaire developed by us included the following sections: general information about education and work experience; subjective assessment of the discomfort of climatic-geographical, industrial and social factors that affect workers during the fly-in period; subjective assessment of the danger of various situations that may arise during the fly-in period; subjective assessment of the hazard in the workplace and the factors contributing to its formation. As a result of the study, it was found that production factors and the likelihood of emergencies create greater discomfort for employees. In this connection, ensuring safety at the facility is of great relevance for the workers of the offshore oil production platform. Among social and household factors, the first place is the maintenance of relationships with relatives and friends, ensuring the possibility of communication and participation in family life. Positive family relationships, as well as a positive socio-psychological climate in the team are important resources for overcoming the adverse effects of environmental factors.
Waterflood Optimization Planning Based on MRT Analysis of Long-Term Bottom-Hole Pressure Records
Authors: Ganiev Bulat , Lutfullin Azat , Farakhova Rushana , Gulyaev Danila , Zinurov Linar , Aslanyan Arthur 
Published: October 2020

Abstract
In case of brown fields and fields currently undergoing drilling, it is highly important to revise field geology to effectively design pressure support and further refine the existing pressure maintenance system if required. At the same time, the analysis of cross-well interference using Multiwell Retrospective Testing (MRT) is very useful for assessing its effectiveness, and is the main tool, that was used at one of the fields in Tatarstan Republic.
Conventionally to identify the geological structure and assess the reservoir connectivity it is required to use tools that could be quite costly, require expensive field operations and take up a lot of time. These tools include seismic surveys, paleotectonic analysis of the survey zone, tracer surveys and interference tests. Each of these methods comes with well-known disadvantages: weak seismic sensitivity to low-amplitude faults, poor resolution of tectonic analysis, long duration of tracer surveys and their low performance against man-made fractures and inconsistent extension in lateral anisotropy of the reservoir, huge production losses during interference tests due to receiving well shut-ins. In this regard, the MRT technology was chosen as the main tool for assessing pressure support at the brown field. This technology is fully fledged and is currently being implemented at a large-scale, having passed the testing stage on both synthetic and actual fields (Aslanyan, 2019) (Aibazarov, 2019) (Ganiev, 2019) (Kovalenko, 2018) (Krichevsky, 2017). Based on previously collected bottom-hole pressure readings registered during the well production and on production history of a set of analysed wells, the of cross-well interference was restored using multi-well deconvolution algorithms as well as proposals for production increase.
In accordance with the conducted surveys, the reservoir geology was refined, inefficient injectors in terms of pressure support was identified, and it was advised to redistribute the injection to balance it out that will ultimately lead to production increase.
Effect of Pore Size Distribution on Phase Behavior of Sour Gas and Hydrocarbon Mixtures in Tight Oil Reservoirs
Authors: Wang Lei , Ismailova Jamilyam , Uteubayeva Yeldana , Chen Jiaheng , Kunzharikova Klara 
Published: October 2020

Abstract
Carbonate reservoirs in North Caspian Sea region of Kazakhstan produce high concentrations of sour gas or acidic gas species, including H2S and CO2. Effect of sour gas components on phase behavior of hydrocarbon mixtures in these fields needs to be clarified. In addition, some of these reservoir formations are very tight with majority of pores falling in the nanometer range. Therefore, nanoconfinement or capillary effect could play an important role on phase behavior during sour crude oil production and sour gas injection processes.
Gas chromatography was employed to analyze the composition of a live crude oil obtained from a Caspian reservoir and a nanopore system with a pore size distribution (PSD) that is characteristic of tight carbonate reservoirs was set up to regulate the vaporization sequence. Using a flash calculation procedure that incorporates capillary effect, phase behavior of sour crude oil in nanoporous media was studied. Specifically, pressure and temperature (PT) diagrams, constant composition expansion (CCE), constant volume depletion (CVD), and CVD with a critical gas saturation (CGS) were simulated and analyzed.
The live crude oil has an average molecular weight of 56.12 g/mol at bubble point pressure and reservoir temperature, containing 13.32 mol% H2S and 2.90 mol% CO2. PT diagrams showed that the bubble point pressure of sour crude oil is much lower than crude oil analogies that use CO2 and CH4 as substitutes by following the order: H2S&lt;CO2&lt;CH4. Nanoconfinement suppressed liquid vaporization in nanopores in CCE and CVD processes, thus keeping liquid phase at low density and viscosity. Setting a CGS helped expel liquid out of the nanopore system during depletion. CCE and CVD processes indicated that more than 42.0 vol% of the nanopores, including part of the 30 nm and all smaller pores, could be always occupied by liquid phase.
These findings are useful for designing, implementing, and simulating sour crude oil production and sour gas injection processes in tight carbonate reservoirs in the North Caspian Sea region.
Pressure Transient Analysis: Insight from Industry
Authors: Mukanov Adil , Kassenov Duman , Kudalsha Aimurat 
Published: October 2020

Abstract
PKKR JSC operates a couple of dozens of fields with more than a thousand wells. Consequently, a massive wells' surveillance program is conducted which includes pressure transient testing (PTT) and analysis (PTA). It leads to different kinds of cases which, eventually, help us to understand challenging issues. Thus, in the paper we try to shed light on how these data are critical to make the right decision with the aim of getting economical benefits for the company.
Field operation performs PTT on 70-80 wells annually such as pressure buildup and deliverability on producers, pressure falloff on injectors and interference tests on observation wells. All the tests are interpreted by the engineers of the company refusing from service companies during oil price decline in 2015 and purchasing commercial software. Using the software interpreter builds Horner and log-log plots, IPR curve which give the quantitative and qualitative parameters of near the wellbore, undamaged zones and outer boundary conditions. This information coupled with geological and production data are analyzed to gather puzzles into one full picture.
As the result of PTA the company could make important decisions which brought to millions of dollars of savings and earnings. The paper demonstrates standard cases, e.g. a pressure buildup test on a well helped to decide to execute fracturing and multiple time increase in oil rate was obtained. Oppositely, on another well falloff test showed presence of fractures, hereby, planned stimulation measures were cancelled in spite of low injectivity. In addition, falloff tests give additional information on how waterflooding is effectively carried out. Another case which was under active discussion includes the issue of converting a well to water injection, so we conducted an interference test and it reveals no response on adjacent producers. Again the company avoided the wrong decision and waste of money. Moreover, interference tests played a vital role in an extraordinary case where it was unclear how the wells produced gas more than reserves. Unexpectedly, the reason was a communication between two lithologically different reservoirs via fractures. So, it dramatically changed the geological concept of the field. There are other situations when PTA results help to characterize geometry of the reservoirs, presence of faults, their transmissibility, fractures distribution which all are critical for static modeling and dynamic simulation.
PTA is a crucial part of geology and petroleum engineering. It essentially helps engineers and managers to make right decisions. Sometimes it leads to big savings or significant profit earnings due to conducting or avoiding the works. Also PTA can change the geological picture of the whole field if properly analyzed. Thus, it is a powerful tool in the hands of geologists, reservoir and production engineers.
Simulation of Multistage Acid Fractures in Horizontal Well Using Multiple Grid Geometry: Tight Carbonate Reservoir Case
Authors: Volnov Ignatiy , Rojas Danny , Bibolova Assem , Lim Kok-Thye , Amiotte Jerome 
Published: October 2020

Abstract
Multiple methodologies and grid geometries were applied to model the production performance and uncertainties in the planning and execution of a pilot horizontal well with multiple hydraulic fractures. The well is located in a tight carbonate formation and the fracture will be induced hydraulically with acid. A methodology was established to scale the observations of the single well model to a full field scale. This, when calibrated against actual performance from the pilot well, will enable improvements in the planning the development of the target reservoir at full field scale.
The methodologies described in this paper consist of fine grid models to explicitly represent the fractures, a method to calibrate and represent the production performance on a coarse grid full field model.
In the fine grid model, the grid was geometric refined to fracture aperture grid size to capture the physics and flow behavior induced by the acid-fracs. Fracture plane conductivity is based on laboratory measurement of acid-frac experiments. The fine scale model was also used in sensitivity analysis to optimize the pilot well design such as number of fractures and desired fracture height growth, identify risk of water production and help formulate of mitigation strategies.
To enable modeling at full field scale – which is impractical with fine grid models – a novel methodology was established to calibrate a coarse grid field scale model to consistently reproduce the fine grid model behavior. This enables early planning of full field development should the performance of the pilot well support the application of multi acid-frac horizontal well as the preferred technology.
An Overview of Reserves and Resources Evaluation in Unconventionals
Authors: Canbaz Celal Hakan , Temizel Cenk , Ozesen Ahsen , Gayde Simel , Aksahan Firat 
Published: October 2020

Abstract
Reserve/Resource estimation plays a crucial role in a feasible oil and gas business. Tendency of producing more from unconventional reservoirs and their relatively new as well as different structure brought on a learning curve for the applications of new reservoir evaluation methods. This study clearly desribes all reserve and resource evaluation techniques, the latest developments in this area by providing a single-source up-to-date reference for reserves evaluation in unconventionals.
An extensive review of literature has been applied to describe all available reserve evaluation techniques and their utilization, applicability and robustness, the history of using these techniques, types of technologies which applied in conventional reservoirs and transferred to unconventionals, and their incremental benefits of usage.This paper includes a real worldwide case studies which are illustrated with applications, and briefly describes the challenges, drawbacks, also pros and cons case by case. In the end, each case leads to conclusions on the criteria of application of methods as they related to SPE, SEC and PRMS.
In this study, "reserve and resource estimation" of unconventional reservoirs is investigated. The techniques are described by giving their methodology, as well as identifying the crucial parameters and the key factors of the applying procedure for the estimations. For instance, the main key factor of reserves evaluation is consistency and abiding by the rules outlined by SEC, PRMS and other bodies in terms of technical and economic aspects.
Currently, some studies includes the certain examples of reserve evaluation methods in conventional reservoirs, and limited number of works in unconventionals. However, there is no study which is not only outlines the key elements in one study, but also deducts lessons from the real field applications that will shed light on the utilization of the methods in the future applications. This study will close the gap and become a reference study in unconventional oil industry.
Optimization of Well Testing for Current Reserves Estimation with Modern Wireline Formation Testers and Open Hole Logs in Exploration Wells Drilled in High Porosity Sandstone Suprasalt Sediments Field
Authors: Blinov Vladislav , Filimonov Anton , Ramatullaev Samat , Tasemenov Ernur , Saparova Saule 
Published: October 2020

Abstract
In Western Kazakhstan, post-salt high porosity clastic reservoirs of the Caspian Basin of Jurassic and Triassic age are represented by multilayer and multi-contact deposits having several gas-oil (GOC) and oil-water contacts (OWC), formed by channel deposits. Reservoirs have good formation properties. Application of advanced logging suite allows to delineate all the key reservoir properties, such as effective oil-saturated thicknesses, all the types of contacts (GOC, GWC, OWC) along with some other properties. However, in such type of reservoirs, it is important to determine a connectivity of individual lobes/lenses – different small parts of deposits. This can only be achieved via well testing and fluid sampling.
Traditional well testing has long been a must during the exploration stage to obtain vital information on reservoir dynamic properties. Usually, it is rather a tedious and time-consuming process, especially when there are many uncertainties on reservoir fluid saturations that can lead to increased well construction costs. This paper will discuss an example on how to optimize and accelerate well testing stage using advanced wireline formation tester and extended logging methods in an open hole, which, in turn, allows for faster commissioning of reservoirs into production.
It is important to note that wireline formation testers cannot fully replace traditional well testing of wells and reservoirs; however, they significantly expand and improve the capabilities traditional well testing has to offer. Therefore, the most optimal solution proposed by Embamunaigas was the joint use of results of wireline formation tester and traditional well test data in green fields. This workflow has successfully been tested in its license areas in recent years.
Maple Syrup Urine Disease in Brazilian Patients: Variants and Clinical Phenotype Heterogeneity
Authors: Margutti Ana Vitoria Barban , Silva Wilson Araújo , Garcia Daniel Fantozzi , de Molfetta Greice Andreotti , Marques Adriana Aparecida , Amorim Tatiana , Prazeres Vânia Mesquita Gadelha , Silva Raquel Tavares Boy da , Miura Irene Kazue , Neto João Seda , Santos Emerson de Santana , Santos Mara Lúcia Schmitz Ferreira , Lourenço Charles Marques , Tonon Tássia , Sperb-Ludwig Fernanda , de Souza Carolina Fischinger Moura , Schwartz Ida Vanessa Döederlein , Junior José Simon Camelo 
Published: October 2020

Abstract
Background: Maple syrup urine disease (MSUD) is an autosomal recessive inherited metabolic disease caused by deficient activity of the branched-chain α-keto acid dehydrogenase (BCKD) enzymatic complex. BCKD is a mitochondrial complex encoded by BCKDHA, BCKDHB, DBT, and DLD genes. MSUD is predominantly caused by Variants in BCKDHA, BCKDHB, and DBT genes encoding the E1α, E1β, and E2 subunits of BCKD complex, respectively. The aim of this study was to characterize the genetic basis of MSUD by identifying the point variants in BCKDHA, BCKDHB, and DBT genes in a cohort of Brazilian MSUD patients and to describe their phenotypic heterogeneity. It is a descriptive cross-sectional study with 21 MSUD patients involving molecular genotyping by Sanger sequencing. Results: Eight new variants predicted as pathogenic were found between 30 variants (damaging and non-damaging) identified in the 21 patients analyzed: one in the BCKDHA gene (p.Tyr120Ter); five in the BCKDHB gene (p.Gly131Val, p.Glu146Glnfs*13, p.Phe149Cysfs*9, p.Cys207Phe, and p.Lys211Asn); and two in the DBT gene (p.Glu148Ter and p.Glu417Val). Seventeen pathogenic variants were previously described and five variants showed no pathogenicity according to in silico analysis. Conclusion: Given that most of the patients received late diagnoses, the study results do not allow us to state that the molecular features of MSUD variant phenotypes are predictive of clinical severity.
Effectiveness and Tolerability of Repetitive Transcranial Magnetic Stimulation for Preventive Treatment of Episodic Migraine: A Single Centre, Randomised, Double-Blind, Sham-Controlled Phase 2 Trial (Magnet-EM).
Authors: Safiai Nabil Izzaatie Mohamad , Amir Nur Ain , Basri Hamidon bin , Mat Liyana Najwa Inche , Hoo Fan Kee , Khan Abdul Hanif Khan Yusof , Loh Wei Chao , Chia Peck Kee , Ramachandran Vasudevan , Din Hazwan Mat , Samsudin Intan Nureslyna , Fernandez Aaron , Mohamed Mohd Hazmi , Ching Siew Mooi , Hashim Hasnur Zaman , Sulaiman Wan Aliaa Wan 
Published: October 2020

Abstract
Background: This is a phase II randomised, double-blind, sham-controlled trial to evaluate the effectiveness and tolerability of repetitive transcranial magnetic stimulation for preventive treatment of episodic migraine among migraine subjects. Methods: Subjects age 18 to 60 years will undergo a baseline evaluation to establish the diagnosis of migraine based on International Classification of Headache Disorder 3rd Edition (ICHD-3). Those who fulfil the ICHD-3 criteria for episodic migraine and compliant to the headache diary during a month run-in period will be enrolled. A total of 76 subjects will be randomised to receive either transcranial magnetic stimulation or sham stimulation for 5 sessions within 2 weeks duration. Follow-up sessions will be conducted monthly for three consecutive months. Prior to treatment, subjects will be required to fill up questionnaires and undergo few procedures such as electroencephalography, transcranial doppler ultrasound and biochemical analysis for serum serotonin, serum calcitonin-gene related peptide and serum beta-endorphin. These procedures will be repeated at month 3 after receiving last treatment. The primary outcome measure of this study is the difference in mean monthly migraine days at baseline and at month 1, 2 and 3 after treatment sessions. Discussion: Following evidence from previous studies showing restoration of dorsolateral prefrontal cortex (DLPFC) activation to almost normal level, the rTMS intervention will target left DLPFC in this study. An intermediate duration of treatment sessions is selected for this study. It is set to five treatment sessions given within 2 weeks duration. Trial registration: NCT03556722. Transcranial Magnetic Stimulation in Episodic Migraine (Magnet-EM) was registered on 27th April 2018. https://clinicaltrials.gov/ct2/show/NCT03556722.