bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Insight into Friction Reducer Evaluation for Slickwater Unconventional Fracturing
Authors: Karadkar Prasad , Alabdrabalnabi Mohammed , Bataweel Mohammed 
Published: November 2020

Abstract
Slickwater fracturing has increased over the past couple of decades in the development of shale and tight formations. Friction reducer is the main component of slickwater, which reduces drag in the tubular. For successful and economical slickwater hybrid fracturing treatment, selection and optimization of friction reducers play a key role. This paper presents a new insight into optimizing friction reducer using helical coiled flow loop at high-pressure, high-temperature (HPHT) conditions.
Usually, friction pressure is estimated by pumping slickwater fracturing fluid through a straight tube and measuring differential pressure across the tube. This required pilot-scale laboratory setup and testing at HPHT bit challenging. In this paper, small sized equipment, helical coiled flow loop was utilized to estimate friction pressure of slickwater fracturing fluid. Friction reducers can be rigorously tested for degradation because secondary flow resulting from centrifugal forces can be caused by the coil curvature. Correlations for Darcy friction factor as a function of Reynolds number has been developed for helical coiled fluid loop in both laminar and turbulent flow regime.
The present study evaluates different friction reducers in ¼ in. ID smooth helical coiled flow loop. The correlations developed for Darcy friction factor was well validated for water with data available from literature. Polyacrylamide based friction reducers with different concentration were used in this study. The friction pressure, with and without friction reducers, was compared at different flow rates. Percent drag reduction at different polymer concentration was also evalauted using helical coild flow loop. Thermal degradation of friction reducers was evaluated by varying temperature up to 300°F.
New correlations to measure friction losses using helical coiled flow regimes are presented in this paper. Reduced drag reduction due to secondary flow resulting from centrifugal forces in helical coil can judge friction reducer more thoroughly then conventionally used straight tube flow loop.
Digital Concept and Machine Learning for Cost Estimation of Oil and Gas Development
Authors: Muhammad Abdull Jamil Kamilah , Lebang Yusuf Theo , Farid Mohd Faidsal 
Published: November 2020

Abstract
The aspiration of cost estimation for oil and gas development is to deliver sharper, accurate yet competitive estimates. Accuracy of cost estimation highly depends on certain attributes such as scope definition and project schedule. In addition to that, uncertainties and pace of change in oil and gas market such as fluctuation of oil price and supply chain, trade wars and geopolitical issues, are external challenges that will affect the accuracy of cost estimates.
Strong database is required to predict the cost based on historical and future market rates. One of the solutions is using probabilistic model to have range of possible outcome for an estimate. Recently, computing techniques such as data analytics and machine learning for quick and accurate cost estimation has been seen as an alternative to overcome the uncertainty of input parameters. Digital Concept such as Machine Learning leverages on statistical approach, nonlinear equations and genetic algorithm programming is used to model the cost. The metrics are used to supply meaningful and timely management information regarding techniques and process. Cost Estimate Relationship (CER) is established to model the correlation against the technical deliverables at any stage gate process to support the target metrics.
This paper presents an alternative method to estimate the cost which is applied to offshore platforms through machine learning as it compares the performance of two different machine learning algorithms: Support Vector Regression (SVR) and Artificial Neural Network (ANN). A comparison between SVR and ANN method is set to show the fundamental algorithm of each and evaluate the comparison between them to show the advantages and limitations. Performance of the algorithm is measured by the RMSE value, which in this case the predicted platform cost by the model against the actual cost observed. The results show that despite the limitation in the amount of data, the algorithms exhibit high performance with both SVR recording average error or deviation of platform cost of RM 27 million, which is the lowest RMSE value, and ANN recording RM 36 million deviation. In addition to that, both algorithms used in predicting the platform cost have returned highly accurate results when comparing them to actual platform cost generated using conventional method.
New Analytical Approach for Predicting Surge/Swab Pressure Gradient Using Mud Clinging Effect and Frictional Pressure Losses: for Yield Power Law Fluid
Authors: Krishna Shwetank , Ridha Syahrir , Vasant Pandian , Ilyas Suhaib Umer 
Published: November 2020

Abstract
Surge and swab pressure generated during pipe tripping operations tends to result in various wellbore stability and integrity problems. To monitor these problems, prediction of these differential pressure is required for the smooth functioning of drilling operations. An analytical predictive model is presented in this research for surge and swab pressure. This model is developed under steady-state condition for Yield Power Law fluid. A fluid filled wellbore with drill-pipe/casing is considered as two concentric cylindrical pipes for developing this model. In this concentrical cylinder inner pipe is moving at certain velocity and the outer pipe is stationary. Due to movement of inner pipe, drilling fluid will start displacing in annulus and results in pressure surges. A predictive model is developed by analytically combining the frictional pressure loss and mud clinging effect to forecast this pressure surge due to couette fluid flow phenomena in wellbore. The newly developed model (NDM) is validated with two existing analytical models and reported experimental data that are available in the published literature. A parametric analysis is carried out to identify the effect of various parameters on pressure differential. This research suggests that with the increase in pipe tripping velocity, surge pressure also tends to increase because of high viscous drag of fluid. It is also found that the increase in diameter ratio surge pressure also tends to increase due to large shearing effect between pipe wall and fluid. In conclusion this model is predicting the suitable range of tripping speed and diameter ratio under tolerable wellbore pore and fracture pressure to assure downhole wellbeing. Unlike most of the existing model, NDM requires less numerical analysis which make it easier to understand and apply in real case situation. The model considers mud clinging effect for precise prediction of surge/swab pressure gradient.
Recent Developments in Surfactant Flooding for Carbonate Reservoirs Under Harsh Conditions
Authors: Adila Ahmed S. , Al-Shalabi Emad W. , AlAmeri Waleed 
Published: November 2020

AbstractSurfactant flooding is one of the most promising chemical enhanced oil recovery techniques. However, this technique has been mainly applied in sandstone rocks with limited applications in carbonates. In this study, we present a comprehensive review on surfactant flooding for carbonates under harsh conditions of high temperature and high salinity. This review starts with highlighting the underlying mechanisms of surfactant flooding. Surfactant types, screening studies, and surfactant retention are then discussed. Laboratory and modeling works as well as field applications are also summarized. In addition, other surfactant applications such as surfactant-polymer, alkaline-surfactant-polymer, low salinity-surfactant as well as foams are presented. At the end of this paper, a list of recommendations and conclusions for better implementation of surfactants flooding are also discussed. This paper gives more insight into surfactant flooding aspects and its different applications in the petroleum industry. The literature review shows that a field-scale application of surfactant flooding in carbonates under high temperature and high salinity conditions is feasible. Also, this paper is considered as a guide for implementing potential projects on surfactant flooding in carbonates under harsh conditions.
A Different Approach to Offloading a Newly Drilled Deviated Well
Authors: Rehman Abid Ur , Abdelbary Marwan 
Published: November 2020

Abstract
As the industry rebounds from recent pricing challenges, operators are searching for methods during each stage of their well—from drilling to production—to make the field more economical without compromising safety, health and quality. This paper describes a different method for offloading a newly drilled well.
In 2017, a well drilled in north Iraq targeted five productive zones. This directional well had a good potential to flow from upper zones which were producing around 3,000 BPD cumulative production. To get production from the upper four zones, conventional coiled tubing (CT) was utilized, and the well started to flow after lifting the drilling fluids. After testing the upper zones, the operator planned to evaluate the lower zone for the production. The well completion had sliding sleeve doors (SSD) and was installed for every zone separately. This well used a jet pump for offloading fluids from the last zone.
The upper four zones were plugged using the SSD, so only the last zone was open for flow. A jet pump was designed using jet evaluation and modelling software (JEMS). The design was based on the optimum size of the nozzle and throat selected for the lowest zone. A downhole jet pump was modified, based on the existing SSD, and installed in the well using slickline. High-pressure power fluid was injected into the well from the annulus and returns were taken from the tubing. The well was successfully offloaded using the jet pump. The well was then tested for production using the same jet pump system, which resulted in around 1,300 BPD production. Jet pump systems require critical observation and proper understanding of the system for this kind of application.
The well was economically offloaded using a jet pump system. This method saved a significant amount of time and money for the operator. Additionally, the jet pump system can be easily installed, designed and modified as per well and completion specifications. The nozzle throat combination can be changed on-site, depending on production results. The installation and operation procedure will be explained in detail for a comprehensive understanding of the system.
Well Condition Diagnosis of Sucker-Rod Pumping Wells Based on the Machine Learning of Electrical Power Curves in the Context of IoT
Authors: Wang Cai , Xiong Chunming , Zhao Hanjun , Zhao Ruidong , Shi Junfeng , Zhang Jianjun , Zhang Xishun , Huang Hongxing , Chen Shiwen , Peng Yi , Sun Yizhen 
Published: November 2020

AbstractSucker-rod pumping wells are the most widely used producing wells in China. 94% of the 200,000 oil wells in CNPC are sucker-rod pumping wells. It is urgent to reduce the cost of every single well based on the well diagnosis and optimization methods under the background of low oil price and the IoT. Rich working experience of field engineers could help them diagnose some conspicuous abnormal well conditions by electrical power curves easily, but the scientific diagnosis methods have still not be established, and the potential of electrical power curves of the producing well is far from being fully tapped.The aim of this work is to diagnose the working condition of the sucker-rod pumping wells both on and under the ground based on the data from electrical power curves by machine learning. The methods shaped by the learning of the electrical power curves from nearly 600 wells mainly separate into 3 steps. The first is the diagnosis of conspicuous abnormal well conditions such as motor belt burning, motor belt slippage, two phase electrics, upper rod break, lower rod break et al. The prediction experience was obtained from the statistical learning of the mean and variance values after we equally split the 600 power curve values into 10 sub-groups. The second is the diagnosis of complex abnormal well conditions such as abnormal mechanical sound, slight tube leak, severe tube leak, pump stuck et al based on the combination of statistics and template vs diagnosed sample analysis. The third is the diagnosis of pumping conditions characterized by the remarkable prediction ability via deep learning. A surface well condition database was established and the corresponding electrical power curves were marked in real time. Based on the CNN technology, the model could recognize different pump working conditions such as insufficient liquid, gas influence, traveling valve leak, standing valve leak et al very well.The work has been applied in the oil fields of Jilin and Daqing. The method has been tested on nearly thousand hundreds of producing well utilizing sucker rod pumping system. The model demonstrates very high accuracy with almost 90% similarity to the result diagnosed by corresponding pump dynamometers for large sample and 94% of abnormal well working conditions for small sample. What’s more, the work would reduce millions of investment on the sensors, equipment and manpower for the management of producing wells in CNPC each year in the context of industrial IoT.
Countercurrent Flow of Heat in Tubing and Annulus System: Jet Pump
Authors: Jang Minsoo , Hasan A. Rashid 
Published: November 2020

Abstract
Shale fields are currently over-reliant on electric submersible pumps (ESPs) in the early stage of artificial lift. However, harsh well conditions such as sandy and/or excessive gaseous flow increase the operational and capex for ESPs. Jet pumps are reliable and cost-effective alternative options for delivering significant savings and its dominance on the market is increasing. Current studies on jet pumps are mainly focused on the design parameters for maximizing performance of jet pumps. However, there have been very few investigations on predicting temperature profiles in the wellbore when with a jet pump.
In this paper, we present analytic models to compute temperature profiles in the tubing and annulus simultaneously throughout the wellbore. Our results illustrate that the temperature profiles in both conduits are nonlinear, and the difference between the two temperatures are not significant, especially near bottom-hole depth. Fluid temperature influences its viscosity, and hence, production operations. Utilizing the proposed model, we investigate the viscosity variation along the depth of the wellbore for better operational design with jet pumps. Generally, viscosity variation with temperature gets larger as the hydrocarbon has more heavier components, therefore, temperature prediction is very important in wells producing heavy oil.
Sensitivity studies have been conducted regarding the impact of operating parameters such as injection fluid temperature and flow rate on fluid temperatures. Injection temperature affects the annulus temperature profile in the swallow depth, leading to a distinctive change of the frictional pressure loss. In contrast, injection rate has less influence on temperature profiles, although of course, higher fluid velocity in the annulus cause greater frictional loss. According to the results, hotter and relatively small flow rate leads to lesser cost by reducing the frictional pressure drop during the operation.
An Innovative Flexible Pipe Annulus Monitoring System to Cover a Wide Range of Riser Applications
Authors: Raman Venkatalakshmi , Delcroix Olivier , Protasio Marcelo , Wasserman Francis , Albuquerque Victor , Turatti Augusto , Carvalho Claudio , Santos Renato 
Published: November 2020

Abstract
Annulus condition is a key information to follow up integrity of flexible risers in service. Traditional ways to measure water level in annulus are performing offshore inspection or monitoring with "passive" systems. This paper presents ISAGM (Instrumented System for Annulus Gas Monitoring) -an innovative "active" monitoring solution that enables permanent surveillance of this important informationwith the particularity of covering a wider range of riser applications thanks to a deep understanding of the kinetic behavior of the annulus with regards to pressure and gas flow.
The system is autonomous, capable ofmonitoring several risers in parallel and based on the injection of nitrogen at low pressure (below 1barg). As it is not relying on the gas diffusion process from the riser, it allows a more accurate and reliable data interpretation compared to the traditional passive way.
First of all, ISAGM description and principle are introduced elaborating on the two first world commercial applications, including one for a Malaysian field. Then, the results of tests on a reference bench rig and flexible pipe are presented. Finally, the challenge of performing annulus free volume measurement of riser interconnected annuli with high diffusion rate is presented through test and simulation results.
An Environmentally Friendly Method for Treating Acidizing Flowback Fluid in Carbonates Reservoir
Authors: Gao Jichao , Yang Shuhui , Yang Guowei , Shao Shangqi 
Published: November 2020

Abstract
Flow back fluid during matrix acidizing in carbonates reservoir has the characteristics of complex composition, variable physical and chemical properties, high content of crude oil and suspended solids. If discharged directly to the ground, it will cause serious environmental pollution and waste resource. A novel and environmentally friendly treatment method to solve this problem has been developed by optimizing surface flow back process, selecting chemicals, modifying filter types and equipment structure. The overall treatment strategy is to separate oil, gas, water and solid phase, inject dehydrated crude oil into pipeline, ignite gas, discharge water after meeting the requirements of industrial wastewater discharge standard, and treat solid phase harmlessly. Some problems such as emulsification, foam fluid and organic scale have been solved by optimizing acid recipe and adopting new chemicals. This novel technique successfully solved the environmental pollution problem and has high economic benefits.
Utilisation of Front End Loading Planning in Technology Readiness Level 5 TRL 5 for Foam Assisted Water Alternating Gas FAWAG and Polymer EOR Pilot
Authors: Hanafiah Norshariza , Chai Ching Hsia Ivy , M Yusof M Faiz , Abu Bakar M Azuan , M Sahak M Zakwan , Shaharom Shaharil Mazri , A Salam Irzie Hani 
Published: November 2020

Abstract
This paper discusses on planning and integration works of two Enhanced Oil Recovery (EOR) pilot projects (Foam Assisted Water Alternating Gas (FAWAG) and Polymer Injectivity test) via utilization of front end loading in Technology Readiness Level 5 (TRL 5) starting from Stage Gate 1 to execution. This pilot is a single well huff and puff pilot injection is to proof the two chemicals performances concept at near wellbore area in order to meet Technology objectives and maturation. The planning covers pilot injection schemes, injection facilities, chemical preparations and pilot test’s surveillance and monitoring program. In Stage Gate 1, chemical screening and feasibility studies were conducted whereas in Stage Gate 2, three concepts identified; which are, pilot on accommodation work barge (AWB), jack-up barge or ‘on platform’ concept with only one being selected for Front End Engineering Design (FEED) in Stage Gate 3. FEED study includes design for chemical injection, volumes and flowback system, offshore logistic selection as well as pilot surveillance. Since key drivers of this EOR pilot project is on cost, consideration on fit for purpose design and procurement strategy is crucial in ensuring data to be collected for pilot. Stage Gate 1 result is the invention of chemical formulation via the screening process with RND criteria achieved for the intended fields. Stage Gate 2 has resulted pilot concept of single well injection with facilities on platform. In Stage Gate 3, FEED study has resulted chemical injection process and flow back design. The study includes chemicals dispersion analysis and chemical blending upscaling process, based on lab scale data. Pilot injection test scheme workflow was developed to cover any uncertainties risk during operation. In Stage Gate 3, the planning processes were enhanced with value engineering study, risk assessment, technical reviews such as Hazard and Operability Study (HAZOP), Hazard Identification (HAZID), 3D model reviews, etc. In execution stage, technology providers and vendors for offshore logistics, surveillance monitoring and data logging, polymer mixing systems and EOR produced water treatment are among the vendors being engaged and considered to assist pilot operation. In conclusion, a thorough project planning is crucial for any EOR pilot project in order for the pilot to be operated successfully. This paper will contribute additional information to the EOR application specifically in Pilot stage to fulfill the Technology readiness level before being fully applied to the oil field. By sharing this EOR Pilot planning and know-how, technology professionals may be able to plan their project at highest value functions and getting optimum pilot design while successfully meeting their technology objectives and mitigating the uncertainties of the Technology.
Rigid Riser System: Alternative System for Coiled Tubing Rig Up on Spar
Authors: Raman Intiran , Selamat Kasim , Ghazali Muhammad Nabil , Blacklock Jon David , Chabot Luc , Ramnarine Ronald 
Published: November 2020

Abstract
A rigid riser system has been designed, built, and proven as an effective method to conduct coiled tubing operations on floating platforms. This system is installed above the Christmas tree which is supported by the platform's production riser and riser tensioner system. The rigid riser set up is a passive system that does not require the use of a crane or other mechanisms to support or hold up the coiled tubing injector head during operations. The axial load resulting from the weight of the injector head, coiled tubing, and snubbing/pulling forces on the pipe are carried in compression through the rigid riser to the tree and wellhead. The excess capacity of the top tensioner riser (TTR) supports these loads while allowing for relative motion due to tide, waves, and platform motion.
The rigid riser system uses a purpose-built, heavy-wall riser and a spider beam insert to resist buckling effects and bending moments. In practice, this system has improved the rig-up time and mitigated HSE issues as compared to the conventional motion-compensated lift frame method.
In addition, the system has a support frame that increases the rigidity of the injector head and accessories, resisting the excessive bending and torsional loads imparted by back tension and movements of the coiled tubing (CT) reel. An engineering study was performed to determine the dynamic loads and stresses for the various operational and contingency conditions on all the components of the rigid riser system and to confirm sufficient capacity of the TTR system.
The rigid riser system has proven to be a safe and cost-effective solution for coiled tubing operations from a floating platform compared to current motion-compensated jacking frame systems. Coiled tubing well interventions were executed using the rigid riser system, and the operational results have been convincing. The passive nature of the system provides an HSE advantage by eliminating mechanical or human intervention during operation.
This paper reviews the design aspects of the rigid riser system, its advantages over the current coil tubing intervention systems, and the operational results after executing the coiled tubing interventions.