bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Low-Temperature Separation Technology for the Field Processing of Achimov Gas: Challenges and Opportunities
Authors: Ahnert Falk , Chepurnov Aleksandr , Driever Heinrich , Fritz Michael , Kubanov Aleksandr , Istomin Vladimir , Prokopov Andrey , Fedulov Dmitriy , Snezhko Daniil , Dubnitsky Roman 
Published: October 2018

Abstract
During recent years the active development of Achimov deposits in the Urengoy oil and gas-condensate field has begun. The development of these deposits will not only reduce the gas production decline rate from traditional Cenomanian and Valanginian deposits, but will also allow to increase the production of liquid hydrocarbons. The cumulative extraction of gas from these deposits in 2017 exceeded 20 BCM, while production of the hydrocarbon condensate (including unstable and deethanized) amounted to approximately 9 million tons. It is planned to reach the production level of Achimov gas in Urengoy field of 40 BCM/year [1 - 3]. Achimov deposits were discovered in other fields as well, for example in the Yamburg field.
The activity of Wintershall Holding GmbH for development of the Achimov deposit is represented by two Joint Ventures with PAO Gazprom – AO Achimgaz with the operating Gas Treatment Plant UKPG-31 [4] and OOO Achim Development with the future UKPG-41 and UKPG-51.
These plants are designed for gas treatment in accordance with STO Gazprom 089-2010 and extraction of unstable gas-condensate with the properties according to STO Gazprom 5.11-2008 as well as Technical Specifications TU 05751745-02-88 "Unstable gas-condensate in mixture with the associated oil". The composition of unstable condensate (UC) includes not only hydrocarbons C5+, butanes and propane, but ethane and even methane as well. The target components for further processing are the hydrocarbons C5+ and propane-butane fraction.
Field gas treatment at the gas-condensate fields of the Extreme North is mainly performed using the low-temperature separation technology (LTS). The natural gases of Achimov deposits are characterized by the following properties, which allow the identify them as a separate research object [3].
A Large-Scale Study for a Multi-Basin Machine Learning Model Predicting Horizontal Well Production
Authors: Amr Salma , El Ashhab Hadeer , El-Saban Motaz , Schietinger Paul , Caile Curtis , Kaheel Ayman , Rodriguez Luis 
Published: October 2018

Abstract
This paper proposes a set of data driven models that use state of the art machine learning techniques and algorithms to predict monthly production of unconventional horizontal wells. The developed models are intended to forecast both producing locations (PLs) and non-producing well locations (NPLs). Furthermore, results of extensive experiments are presented that were conducted using different methodologies and features combinations. Results are measured against conventional Arps's decline curve analysis showing significant boost in prediction accuracy for both NPLs and PLs. The most accurate model outperforms Arps's-based estimates by almost 23% for NPLs and 36% for PLs. Results also show that using data from multiple basins in training models for another basin yields gains in accuracy, especially for basins with relatively small data.
Pressure Effects on Low-Liquid Loading Oil-Gas Flow in Slightly Upward Inclined Pipes: Flow Pattern, Pressure Gradient and Liquid Holdup
Authors: Rodrigues Hendy , Pereyra Eduardo , Sarica Cem 
Published: October 2018

Abstract
This paper studies the effects of system pressure in oil-gas low-liquid loading flow in a slightly upward inclined pipe configuration using new experimental data acquired in a high-pressure flow loop. Flow rates are representative of the flow in wet gas transport pipelines. Results for flow pattern observations, pressure gradient, liquid holdup and interfacial roughness measurements are presented and compared to available predictive models. The experiments were carried out at three system pressures (1.48, 2.17 and 2.86 MPa) in a 0.155 m ID pipe inclined at 2° with the horizontal. Isopar-L oil and nitrogen gas were the working fluids. Liquid superficial velocities ranged from 0.01 to 0.05 m/s while gas superficial velocities ranged from 1.5 to 16 m/s. Measurements included pressure gradient and liquid holdup. Flow visualization and Wire-Mesh Sensor (WMS) data were used to identify the flow patterns. Interfacial roughness was obtained from the WMS data.
Three flow patterns were observed: pseudo-slug, stratified and annular. Pseudo-slug is characterized as an intermittent flow where the liquid does not occupy the whole pipe cross-section as the traditional slug flow does. In the annular flow pattern, the bulk of the liquid was observed to flow at the pipe bottom in a stratified configuration, however, a thin liquid film covered the whole pipe circumference. In both stratified and annular flow patterns, the interface between the gas core and the bottom liquid film presented a flat shape. The superficial gas Froude number, FrSg, was found to be an important dimensionless parameter to scale the pressure effects on the measured parameters. In the pseudo-slug flow pattern, the flow is gravity-dominated. Pressure gradient is a function of FrSg and vSL. Liquid holdup is independent of vSL and a function of FrSg. In the stratified and annular flow patterns the flow is friction-dominated. Both pressure gradient and liquid holdup are functions of FrSg and vSL. Interfacial roughness measurements show a small variation in the stratified and annular flow patterns. Model comparison gives mixed results, depending on the specific flow conditions. A relation between the measured interfacial roughness and the interfacial friction factor is proposed, and the results agree with existing measurements.
Surface to Borehole Electromagnetics for 3D Waterflood Monitoring: Results from First Field Deployment
Authors: Colombo Daniele , McNeice Gary , Cuevas Nestor , Pezzoli Mauro 
Published: October 2018

Abstract
Monitoring the waterflood oil recovery process is a difficult task for seismic-based methods in hard carbonate reservoirs. The changes in velocity/density due to water-oil substitution are too small when compared to the errors involved in repeating the measurements. We detail the development of a novel technique based on surface-to-borehole controlled-source electromagnetics (CSEM), which exploits the large contrast in resistivity between injected water and oil to derive 3D resistivity distributions (proportional to saturations) in the reservoir. Surface-to-borehole CSEM responses using surface electric transmitters and borehole EM receivers were modeled using a black-oil simulator for a large oil field in the Middle East. Results indicate that the vertical electric field can be used to detect waterfront changes in 2 and 5-year time-lapse scenarios. A surface-to-borehole acquisition system was engineered comprising the development of a powerful, custom-made electric transmitter (2000V/500A) and borehole electric and magnetic field sensors. The surface-to-borehole 3D CSEM technology was deployed for the first field trial in the same well used for the modeling study. The field demonstration was carried out in 2017 comprising 144 permanent surface electrodes drilled in a radial configuration around a vertical observation well. The current electrodes were designed in an L pattern to form 48 inline (radial) and 48 cross-line (tangential) dipoles at a nominal range of 600m to 3,500m from the vertical observation well. A wireline sensor array comprising two vertical electric and two vertical magnetic field sensors recorded the EM signal transmitted from the surface in regularly spaced positions in the reservoir section. Surface measurements of transient EM (TEM), CSEM and magnetotellurics (MT) were recorded together with the borehole acquisition to characterize the overburden and the shallow subsurface. The acquired dataset was processed to increase the signal/noise content of the data as well as to correct for casing effects and surface distortions. A marked asymmetry of the EM responses is recorded in the vicinity of the observation well which translates, after 3D inversion, to resistivity distributions consistent with the saturation/production logs acquired in the nearby wells. The sensitivity of the inversion extends up to 1.8 km away from the observation well. Analysis of the measurement repetition errors compared to predicted EM responses after 2 and 5 years indicates that time-lapse surveys would provide detailed mapping and an independent estimation of saturation variations related to waterflooding. The encouraging results obtained from the first surface-to-borehole CSEM survey in a producing oil field suggests that the technology may become an important tool for analyzing the waterfront evolution in the interwell space. By doing this, the technology is expected to enhance reservoir management and history matching.
Artificial Intelligence–Driven Asset Optimizer
Authors: Gupta Supriya , Sharma Abhishek , Abubakar Aria 
Published: October 2018

Abstract
Currently, as oil and gas companies continue to face risk of volatility in oil prices, production optimization and maintenance play a critical role in driving operational excellence for the industry while maintaining good profit margins. E&P companies must maintain a focus on reducing unit cost/barrel. This can be achieved by reducing operating costs, increasing production, and reducing downtime. We propose a recommendation engine driven by artificial intelligence (AI) that seamlessly integrates subsurface information and production characteristics for knowledge extraction needed to optimize production operations across conventional and unconventional assets. We used a three-phase approach to designing and building an advisory system that ingests data, learns patterns, and feeds these learnings from the data into different functional workflows necessary for improving the efficiency and effectiveness of production operations. The system uses these mechanisms of knowledge extraction, statistical learning, and contextual adaptation as it evolves into an autonomous asset optimization system that can proactively recommend actions for effective decision making to lower the unit cost/barrel.
ESP Surveillance and Optimization System in Smart Fields of Salym Petroleum Development
Authors: Gorlov Alexander , Musorina Anastasia , Terebennikov Valery , Safonov Victor 
Published: October 2018

Summary
In current conditions of oil and gas production the highest significance is the use of intellectual control technologies improving operational activities of the company. The main task of intellectual system is optimization of production, technical solutions, processes of planning and operational expenditures.
SPD pays significant attention to issues of optimization of oil production and production energy efficiency, and in this relation in the beginning of 2016 the company developed and implemented a program of daily analysis of production well stock operation and making decisions on optimization of their operating modes called “Optimization Register".
This system is integration of well and equipment operating parameters in real time mode and technical information from different databases into one base with automatic check of data correctness. This allows to promptly draw attention of Analytical Engineer to arising problems with the well, create a request for actions to re-establish operating mode and send the request to responsible persons for implementation of required actions to stabilize its operating mode. All requests are created in the program and automatically sent to performers. Time of request submission and its closure is strictly recorded by the program, which allows to assess prompt work of different services in the company.
Automatic detection of destabilization of well and/or equipment operating mode, creation and implementation of requests within limits of work optimization now presents a closed cross-functional cycle of information delivery allowing each participant to have all updated information on specific well and leave comments related to his/her responsibility area.
Observations and Complexities in Experimental Measurement of Acid Fracture Conductivity for a Deep Carbonate Field in Kazakhstan
Authors: McDuff D. , Malhotra S. , Comeaux B. A. , Quintero B. W. 
Published: October 2018

Abstract
Acid fracture conductivity experiments provide information valuable to effective design of acid fracture stimulation treatments in carbonates. They are complex tests, and a number of procedural details must be taken into consideration in order to upscale results to an adequate representation of well-scale acid fracture behavior for well productivity predictions. This paper focuses on a study performed on analog, quarried limestone core samples and a small number of reservoir core samples from the Unit 2 formation of Kazakhstan's Tengiz field to understand the impact of different acid fluid systems and procedural steps on acid fracture conductivity.
The physical structure of the etched channels is observed to be impacted by the nature of the fluid and has a strong impact on the conductivity. The quality and uniformity amongst the core samples has a critical impact on the measurements and is assessed. The residence time of the acid in the acid-etched experimental channel is small, and the equivalency of acid volumes injected at the experimental scale to the large acid volumes injected into a well-scale fracture channel is considered. Special consideration is given to the procedure of applying stress to and measuring conductivity of the experimental acid fracture channel which may result in large-scale mechanical failures of the core sample, preventing a high-quality measurement of conductivity following injection of a closed fracture acidizing stage.
This body of work discusses the design options and challenges which play a role in defining the testing strategy for an acid fracture conductivity study. Results demonstrate that with selection of appropriate fluid systems, acid fracture conductivity can be retained up to a closure stress of 6,000-7,000 psi in the Tengiz Unit 2 reservoir. A modified stress ramp-up procedure to improve closed fracture acidizing conductivity testing results obtained through the testing program is presented.
Flow Velocity Estimation in Horizontal Oil Wells Using the Method of Thermal Flowmeter Based on the Fiber-Optic Distributed Permanent Monitoring System
Authors: Ipatov Andrei , Kremenetskiy Mikhail , Lazutkin Dmitry , Skopintsev Sergei , Sharovarin Evgeniy 
Published: October 2018

Abstract
The current improvement of temperature logging informative value in horizontal wells is considered in the article. Examples of production logging in wells with multistage hydraulic fracturing (multi-fracs) and the features of their interpretation are given. The role of temperature logging in the modern complex of production logging gages is considered. The advantages and limitations in the applicability of the methods of classical temperature logging are distinguished, the possibilities of long-term temperature monitoring using the fiber-optic sensor system distributed along the well are considered.
Aim of the present work is to show new findings in the theory of thermal flowmeter on base of fiber-optic data for evaluating the inflow intervals and determining the fluid flow velocity in the horizontal well bores.
The authors proposed a new method of field production monitoring, based on the use of a fiber-optic distributed measuring system as a thermal flowmeter, that is heating a fiber optic cable certain section in order to get from it characteristic of temperature relaxation during its cooling. A mathematical model is developed that justifies the efficiency of the solution and a plan for experimental confirmation of the theory with mathematical calculations is drawn up.
Feasibility Testing of a Pilot-Scale Two-Stage Biofiltration Unit for Mitigating VOC Emissions from a Wastewater Sump
Authors: Khoramfar Shooka , Jones Kim , Boswell James , Shah Aditya , Aggarwal Shubham , Ghobadi Jalil 
Published: October 2018

Abstract
Volatile organic compounds (VOCs) present in crude oil can be released to the atmosphere from storage tanks, wastewaters and equipment leaks in petroleum industries. A pilot-scale sequential biotrickling-biofiltration (BTF-BF) unit as an environmentally safe and economical treatment procedure was designed and tested for removal of VOCs from a wastewater sump at the CITGO Corpus Christi Refinery. To identify and quantify VOC emissions from the refinery wastewater sump, the air was sampled using 6 L canisters and characterized using gas chromatography-mass spectrometry. The pilot-scale unit included a BTF for removal of more water soluble compounds followed by a BF for removal of poorly soluble compounds. Performance of the BTF and BF units containing plastic cross flow and compost-based media were investigated at pollutant loading rates of 6 g/m3hr to 1750 g/m3hr.
The characterization results of the pilot test showed benzene as the main constituent of the vapor stream (85% of vapor) emitted from the wastewater sump. The ratio of benzene to toluene and xylene was determined to be 12:2:1 in these samples. The high concentration of benzene as an amenable food and energy source for the microorganisms lead to high biomass growth and more than 85% removal efficiency (RE) for total emitted VOCs.
Application of an innovative sequential biotrickling-biofiltration unit was also demonstrated to effectively handle the cyclic emissions of VOCs at most oil and gas industries. Although several researches have been done to evaluate the performance of BFs and/or BTFs in the laboratory, this pilot study can be used to design and optimize the performance of a bio-oxidation unit under actual refinery operating conditions.
Features of the Well Test Interpretation in Complicated Conditions of Intensive Segregation of Phases in the Wellbore and the Manifestation of the Effects of Abnormal Pressure Growth.
Authors: Shchurenko Aleksandr , Arbatskii Timur , Dadakin Nikita , Rymarenko Konstantin , Nukhaev Marat , Musin Roman 
Published: October 2018

Abstract
During well tests on producing wells in oil and gas reservoirs on non-stationary flow regimes, the most common technology used is shutting a well on a wellhead, due to little technical and economic resources needed. Using these techniques however willingly implies a range of complicating factors, which have a direct influence on quality of the data on hydrodynamic properties of a reservoir, necessary for further production engineering.
This paper describes the physical-chemical mechanism and diagnostics of such complicating factors as segregation processes in the wellbore, which substantially distort the real pressure response of studied reservoir hydrodynamic system. The paper proposes a method of phase redistribution diagnostic, gives assumptions of causes of complicating segregation effects. In addition, the study suggests some technical and interpretational solutions aimed at improvement of quality and productivity of well tests.
Effective Zonal Isolation in Horizontal Wells: Mitigating Negative Impact of Mud Channels
Authors: Kolchanov Petr , Perroni Dominic , Medvedev Anatoly , Gao Yan , Tercero Randy , Todd Larry , Lungwitz Bernhard , Cowan Kenneth Mike , Turner William 
Published: October 2018

Abstract
Currently, hydraulic isolation of wells drilled with nonaqueous fluids (NAFs) relies heavily on the elimination of mud from the annuli before the placement of cement. Failure to expel all NAFs will result in residual fluid channels that will compromise well integrity and can even serve as nonproductive communication pathways during subsequent stimulation treatments. To mitigate this risk, an interactive cementing system is presented that is designed to reduce conductivity of the residual mud channels.
Although mud removal remains an integral part of the cementing process, this new cement formulation was developed to improve zonal isolation in the case of poor mud removal. The unique cement system reacts with the hydrocarbons present in NAFs, leading to a reduction of channel permeability and mobility. This significantly improves the likelihood of hydraulic isolation. Specialized testing protocols were developed to enable the demonstration of the capabilities of this new system. In addition, API testing methods and analytical techniques were used to optimize the slurry.
The development of the new cement system focused on the optimization of the active component concentration to give a favorable interaction with NAF, and at the same time, minimize the effect on cement rheology and mechanical properties. Procedures developed in-house demonstrated that the new system effectively reduces hydraulic conductivity of microannuli as well as channels up to several tenths of inches in size. Zonal isolation laboratory experiments were extrapolated to predict whether the modified channels can withstand the range of differential pressures typically seen between neighboring fracturing stages. This is the most critical operation that the cement sheath would be subject to.
Field tests are on-going at the time of writing this manuscript, and the preliminary results will be presented and discussed in this paper.
Image Reconstruction in a Tomographic Multiphase Flow Meter: A Greedy Compressed Sensing Approach
Authors: Al-Shuhail Shamael A. 
Published: October 2018

Abstract
The need for flow measurements throughout the production cycle has led to the development of a variety of multiphase flow meters. An ultrasonic tomographic multiphase flow meter is being developed in which it can potentially replace radioactive and invasive types of multiphase flow meters. The meter is configured to generate cross-sectional images of the flow inside the pipe in a non-invasive manner yet with direct contact to the fluid. Image reconstruction is generally carried out via inversion which requires a high level of computation complexity and processing time. It can be further challenged by the limited amount of data available. Compressed Sensing (CS) optimizes the conventional structure for data acquisition and compression. CS is based upon recovering certain data from very few measurements. Loosely speaking, most CS algorithms fall into either two categories; convex optimization recovery and greedy pursuits. In this paper, CS greedy pursuit algorithms are used to reconstruct sound speed images to find the most suitable algorithm in terms of image quality. Specifically, we made a comparative analysis of three greedy CS algorithms; Orthogonal Matching Pursuit (OMP), Compressive Sampling Matching Pursuit (CoSaMP), and Fast Bayesian Matching Pursuit (FBMP). We further compare the CS greedy reconstruction results to a conventional approach for image recovery based on the least-squares problem. Simulation results show that CS algorithms highly outperform the conventional approach for image recovery. Results demonstrate that high quality image recovery can be achieved using these simple greedy pursuit algorithms, sometimes even at increased system efficiency. Out of the three greedy algorithms, CoSaMP shows the highest quality for image recovery. Results also suggest that careful selection of the number of measurements used for recovery is necessary to obtain an accurate image reconstruction. As presented in this paper, our purpose is to adapt a CS approach, specifically greedy pursuit algorithms, for an efficient and an improved reconstruction of images generated by the ultrasonic tomographic multiphase flow meter to accurately quantify phase fractions in producing oil wells.