bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contribution of Oil and Gas Production in The US to The Climate Change
Authors: Lancon Olivier , Hascakir Berna 
Published: October 2018

Abstract
The oil and gas industry has often been blamed for its major contribution to greenhouse gas releases and designated as a target to knock down by media, activists, and environmentalists. It is true to say that without Oil and Gas Industry, anthropogenic emissions of CO2 and CH4 would be much lower. Similarly, it is also true to state that without this industry and petroleum products, our life standards would be much different than the current standards. One should not confuse an activity which generates greenhouse gases, and the effect of product consumption. Evaluating the real routine emissions of the oil and gas industry on the same mode than every other industry is possible and constitutes the objective of this work. As a preliminary result, however, data coming from the Environmental Protection Agency (EPA) clearly highlight that oil and gas production accounts for at least less than 10% of the greenhouse gas emissions from the energy sector in the United States. To more precisely evaluate these emissions, this study relied on environmental impact reports in terms of greenhouse gas emissions, which are available for every production site in the U.S, as well as the oil and gas consumption in the US over the year 2015. Emissions happen during three different stages of the hydrocarbon production; extraction, flaring and venting, and fugitive emissions. The importance of each stage in terms of emissions is extremely variable, depending on the quality of the oil, the field location, and the existence of an outlet for the produced gas. The greenhouse gas emissions contribution from the Oil and Gas industry is 3% for extraction, and about 0% for flaring and venting, and 0% of fugitive emissions in the US. The remaining U.S greenhouse gas emissions while processing petroleum products are due to refining at 88%, and transportation at 9%. However, these results are extremely different for Canadian oil sands, Venezuela heavy oil, Arabian light oil, or Indonesian gas condensate. Worldwide, greenhouse emission source for petroleum industry are 10% for extraction, 19% for flaring and venting, 6% of fugitive emissions, 4% of transport, and 61% of the refinery. As a result, 3.5% of greenhouse gases emitted while processing petroleum products are due to Oil and Gas industry. Based on these results, an extrapolation to the worldwide Oil and Gas production enable to assess the participation of this industry to total emissions. Results show that less than 3 % of worldwide greenhouse emissions comes actually from Oil and Gas industry.
Analysis of Chemical Compositions Injection Combined with Cyclic-Steam Stimulation
Authors: Kuvshinov Ivan , Kuvshinov Vladimir , Altunina Lyubov 
Published: October 2018

Abstract
The paper presents the analysis of cyclic steam stimulation (CSS) application results for producing wells on Permian-Carboniferous deposits of Usinskoye oilfield of high-viscosity oil, the Republic of Komi, Russia. The application of thermotropic chemical compositions for enhanced oil recovery combined with CSS is discussed. Data on treatment of more than 170 cyclic-stean wells for 2017, as well as statistical data on cyclic steam stimulation for 2014-2017 are given. Among the wells considered are both wells treated with steam only, and in combination with chemical compositions of two types, oil-displacing and flow-diverting. The compositions used are thermotropic, using the energy of the injected fluid to activate the necessary chemical reactions, such as gelling or the formation of an alkaline buffer system. Also, the effect of CSS for wells where this treatment is applied for the first time, with wells with multiple CSS (from two to ten cycles), is compared. Experimental curves of efficiency distribution are obtained, expressed in the increase in oil production rate after treatment, for different well groups.
The analysis of the efficiency of the CSS on a large data set was carried out, the asymmetries in the efficiency distribution of the wells were revealed, where the CSS was used for the first time. The first CSS cycle, especially when the well is put into operation from inactivity or after drilling, is most effective, the average flow rate after treatment is 24.0 tons/day, with multiple treatments the efficiency is significantly reduced, a decrease to 5.5 tons/day is observed.
The influence of chemical compositions of various functional purposes on the efficiency of cyclic steam stimulation has been studied. With repeated CSS, the use of the oil-displacing composition is efficient and reasonable, since one of the main declared functions of the composition is precisely the extra washing of the residual oil. The average yield for repeated treatments with a composition is 10.9 tons per day. The use of the gel-forming (flow-diverting) composition with the CSS reduces the water cut of the product by 30-40%, and stabilizes the average result of the treatments, both at low and high efficiencies, so that application of such a composition is undesirable in wells with a high oil production rate before the CSS, but is valid for highly watered wells.
Based on the results of the analysis, it was concluded that for the new wells, the first cycle of CSS is most effective, and the use of chemical compositions is not necessary, but for subsequent cycles, it is recommended to use chemical compositions that will provide afterwashing of residual oil and reduced water cut. For old wells, where no CSS was previously used, it is necessary to evaluate the expediency of using chemical compositions in the first cycles based on the dynamics of the well and the initial water cut.
Study on the Mechanism of Reversing Oil Displacement for Increasing the Production of Crude Oil in Low Permeability and Ultra-Low Permeability Oil Field
Authors: Guan Cuo , Li Yiqiang , Hu Wenrui , Ma Zilin 
Published: October 2018

Abstract
Conventional water flooding method becomes ineffective facing low and ultra-low permeability oilfields, and the recovery rate of the non water harvesting period is only about 20%. Most residual oil is trapped in the reservoir and cannot be recovered. The conversion of injection well into production ones is used on some scale at home and abroad as a technique of oilfield adjustment, stimulation and EOR. Yet, problems like the optimum converting time, microscopic stimulation mechanisms, etc., have not been clearly studied. The optimum time for reverse displacement can be acquired through forward and reverse displacement experiments of man-made cores with different permeability. Then, based on CT scanning technology an analysis is made of the processes of the forward displacement (till the converting time point) and the reverse displacement (till the end). According to the information of pores and water-oil distribution extracted from the CT graphs, water flooding characteristics and the change in residual oil distribution in different layers and at different displacement stages can be recognized. With the process of forward water injection, the residual oil in the core behave as types of discontinuous phases, including film flow, blob flow, slug flow, multi-pore flow, etc., the total volume fraction of which increases with the displacement continuing. During the reverse displacement, in contrast, the former dispersed residual oil gradually gathered in cluster that is comparatively more recognizable. Meanwhile, the amount of multi-pore flow ascend, which is most obvious. These factors made part of the residual oil better displaced. By above analysis, a reasonable microscopic explanation of the stimulation technology by converting injection wells into production ones. The article concisely and directly uncovered the microscopic mechanism of the reverse displacement to enhance oil recovery. Based on the study and taking other influential factors of development into account, instructions can be made on further EOR process of low and ultra-low permeability oilfield at lower costs and with higher efficiency, which is one of the top concerns for most low permeability oilfields.
Comparative Analysis of Different Well Patterns for Steam-Assisted Gravity Drainage
Authors: Fedorov Konstantin , Gilmanov Aleksandr , Shevelev Aleksandr 
Published: October 2018

Abstract
The paper is devoted to the development of SAGD simulation. New integrated model of the process is presented. This model predicts main technologic parameters of the process. Analytical and numerical analysis revealed significant features of the process. Critical steam injection rate was established that is needed for heat channel between injector and producer formation and process initiation. Consideration of stationary state of the process was the basis of maximum volume calculation of steam chamber. In the framework of proposed model, increase of sweep efficiency was considered. Approach for sweep improvement by transformation of well pattern is developed.
Integrated Engineering Approach for Drilling of the First Well in the Laptev Sea
Authors: Grishankov Vyacheslav , Galimkhanov Aydar , Bogdanov Sergey , Kharitonov Andrey , Tikhonov Evgeny , Khalilov Almaz , Berezin Alexander , Dubrovsky Maxim , Tsibulsky Mikhail , Suvorov Anton , Netichuk Igor 
Published: October 2018

Abstract
This document describes the integrated engineering approach and technical solution used to perform a construction project of the first wildcat well in Khatanga subsoil area of the Laptev Sea.
Because of the small scope of performed geological exploration works and the absence of any previously drilled wells within the target area, a low degree of geological knowledge existed for this project. The unique location of the license area eventually complicated the profile of the Centralno-Olginskaya 1PO wildcat well and the logistics on the peninsula, consequently affecting the planning and performance of the project.
In these conditions, RN-Shelf-Arktika OOO and Halliburton encountered a range of challenging tasks associated with high quality planning and safe performance of the expected work scope within the planned timeframes. Other challenges encountered included fulfilling all geological tasks required to reduce expenses and developing technological and organization solutions for the subsequent construction of wells and the discovery of a new oilfield in the Eastern Arctic.
Because of the low level of geological knowledge about the territory, the operator regularly assigned new geological tasks. These changes eventually resulted in a longer wellbore (5530 m, rather than 4200 m), increased scope of geological activities (a longer coring interval of 156 m, rather than 90 m), and well design changes (five casing strings, rather than four).
To ensure the fulfillment of the required tasks, the completion of the project was based on an integrated approach for the integrity of the proposed technological and organization solutions, high quality of planning, and risk management and application of advanced technologies. This approach ensured 100% fulfillment of the geological objectives within the established timeframes and helped to develop a map of lessons learned with recommendations to optimize time and costs in the construction of future wells at the new field. Because of the project remoteness and challenging climate conditions, the well construction cost is the key factor for efficient field development (Lebedeva et al. 2017).
Casing Design Optimization and Technologies Improvement of Horizontal Wells Construction on the Objects of PJSC LUKOIL in West Siberia
Authors: Bondarenko Leonid , Bakirov Daniyr , Kovalev Vitaly , Fattahov Marsel , Fatihov Vadim , Mazur Galim 
Published: October 2018

Abstract
The applying of the horizontal wells during 10-15 years is one of the key direction to improve the effectivity of the development traditional and new hydrocarbons’ fields.
The building of the horizontal wells usually performs in Cretaceous and late Jurassic systems by LLC «LUKOIL - West Siberia». The typical well's construction consists of the directional casing pipe (⌀323,9 mm); conductor (⌀244,5 mm); production casing (⌀177,8 mm) till the production back and liner string (⌀114,3 mm).
To optimize the construction of well due to long duration it was offered the optimized construction (3 stages) for horizontal well, which consists of directional casing pipe (⌀323,9 mm); conductor (⌀244,5 mm); production casing (⌀146 mm). (Fig. 1)
The drilling of horizontal wells with such construction was had high level of non-productive time in 1990. It was due to imperfection of technical and technological solutions, equipment and materials for drilling and completion, that was applied in past.
Because of the positive experience of the applying a new equipment types for bottom hole assembly, drilling fluids, survey technologies during the drilling, multi-stage fracturing, it was actual return to 3 stage horizontal well's construction because it was appeared the opportunity of the doing troubleproof works such as the waiting of cement consolidation around production casing, mounting and hydraulic proof test of the blow out equipment, changing the equipment to drill the liner string's interval, doing geological investigations and other operations. Besides the placement of full-opening casing (⌀146 mm) in horizontal interval allows more technological well's completion and to conduct re-multistage fracking, to investigate and to doing maintenance and isolation operations into the horizontal interval by the traditional technologies and equipment, and another operation into the interval of the productive strata.
New Magnetic Resonance Wireline Sensor for High-Resolution, Faster Logging, and Better Fluid Typing
Authors: Balliet Ronnel , Chen Songhua , Callirgos Manuel , Beard David , Li Lilong 
Published: October 2018

Abstract
A new wireline nuclear magnetic resonance (NMR) logging tool is capable of providing high-resolution logs at a logging speed that is twice that of the typical current MRIL® tool logging speeds. The new sensor features a stronger magnetic gradient to enhance the sensitivity of diffusion-based fluid typing; it also provides a much shorter inter-echo spacing (Te) to increase the data density per echo train. Consequently, the new sensor reduces the requirement of vertical averaging, which enhances the resolution of thin bed formation evaluation.
The new NMR sensor addresses industry requirements for reliable porosity, organic vs. intergranular porosity discrimination, and free vs. adsorbed fluid fractions in low porosity, heterogeneous unconventional reservoir evaluations. The paper discusses optimization aspects of the sensor, including antenna aperture, maximized packing density of frequency bandwidth, and multi-frequency short inter-echo spacings. The new NMR sensor is fully combinable with several nuclear, electromagnetic (EM), and acoustic logging instruments with a log vertical resolution that is comparable to that of wireline density logs.
Field tests from North American unconventional wells have demonstrated that only minimal stacking is needed to meet the 1 PU porosity repeatability and moderate stacking for reliable fluid typing, even in low porosity unconventional reservoirs. With an optimal number of frequencies used for unconventional reservoir applications, an advantage is realized from the total frequency bandwidth for optimal signal-to-noise ratio (SNR). The optimized SNR, in addition to the short Te, also improves the 1D T2 spectral and 2D map resolution and, consequently, free light hydrocarbon and organic pore fluids. Intergranular fluid signals are also resolved in several wells with porosity as low as ≤ 5 PU.
Challenges of Cementing Steam Injection Wells SAGD
Authors: Figilyantov Aleksandr , Chugaeva Olga , Garshina Olga , Okromelidze Gennadii 
Published: October 2018

Abstract
There are a number of high-viscosity oil fields around the world. A distinctive feature of such oil fields is a combination of two factors: high viscosity of oil and low temperature of its enclosing zone. Sometimes, the temperature of pay zone is comparable to the temperature of permafrost + 6 °C.
Thermal methods are used to intensify oil production in such oil fields. The main thermal method is the injection of steam into the formation. The temperature of the injected steam exceeds 200 ° C.
With using this technique of intensification, there is a challenge of keeping the integrity of the cement sheath behind the column, as the cementing conditions and operating conditions are incompatible. The curing of the cement stone occurs at a temperature about + 6 ° C. When the steam is injected, the cement sheath is heated to a temperature of + 195 ° C or more.
Thermal deformations of the columns occur: expansion, elongation, when high temperature is applied. To reduce the probability of steam breakdown due to thermal deformations of the column, thermo compensators are used. Moreover, to compensate for the thermal elongation, the shoe of filter pipe is set upper than bottom was drilled.
Successful Implementation of PMCD Technology in Kazakhstan
Authors: Amanbayev Yerlan , Karmanov Kanat 
Published: October 2018

Abstract
This paper describes the implementation of pressurized mud cap drilling (PMCD) technology, a variant of Managed Pressure Drilling (MPD), a successful technique frequently used on oil and gas fields in Kazakhstan. It also considers the planning phase, operational aspects, and results of drilling with the PMCD technique through challenging formations.
PMCD technology with a rotating control device (RCD) is a form of blind drilling, where the drilling fluid and formation cuttings are not transported to the surface. It is a non-conventional drilling technique designed to maintain annular wellbore pressure to prevent total loss of circulation. A sacrificial fluid (SAC) is injected through the drill string and light annular fluid is pumped down from the annulus to maintain borehole fill and prevent annular gas migration.
Wells in this field have encountered uncontrollable losses while drilling sections of the fractured carbonate. As a result, the application of PMCD technology to meet those challenges was an obvious choice in order to achieve target depth. Conventionally drilling of the 8-in. section resulted in fluid losses of more than 450 m3. Consequently, passing through these challenging zones the rig crew switched from conventional drilling to PMCD. The wells were then successfully drilled using the PMCD method, without any issues or well-control incidents, and planned TD was attained. By enabling the client to reach TD, Weatherford PMCD equipment transformed a previously undrillable well into a potentially valuable asset. This operation demonstrated that PMCD can be a viable drilling technique for future wells in the field.
PMCD technologies included reduced consumption of lost-circulation material (LCM) and reduced loss of mud to the formation, keeping the wells economically viable. The main objectives of these wells were to drill safely and efficiently to target depth (TD), to deliver the wells for production on schedule, reduce non-productive time (NPT), minimize the drilling risks and hazards, and optimize the drilling program.
Robust Uncertainty Quantification through Integration of Distributed Gauss-Newton Optimization with Gaussian Mixture Model and Parallelized Sampling Algorithms
Authors: Gao Guohua , Vink Jeroen C. , Chen Chaohui , Araujo Mariela , Ramirez Benjamin , Jennings Jim W. , Khamra Yaakoub El , Ita Joel 
Published: October 2018

Abstract
Uncertainty quantification of production forecasts is crucially important for business planning of hydrocarbon field developments. This is still a very challenging task, especially when subsurface uncertainties must be conditioned to production data. Many different approaches have been proposed, each with their strengths and weaknesses. In this work, we develop a robust uncertainty quantification workflow by seamless integration of a distributed Gauss-Newton (DGN) optimization method with Gaussian Mixture Model (GMM) and parallelized sampling algorithms. Results are compared with those obtained from other approaches.
Multiple local maximum-a-posteriori (MAP) estimates are located with the local-search DGN optimization method. A GMM is constructed to approximate the posterior probability density function, by fitting simulation results generated during the DGN minimization process. The traditional acceptance-rejection (AR) algorithm is parallelized and applied to improve the quality of GMM samples by rejecting unqualified samples. AR-GMM samples are independent, identically-distributed (i.i.d.) samples that can be directly used for uncertainty quantification of model parameters and production forecasts.
The proposed method is first validated with 1-D nonlinear synthetic problems having multiple MAP points. The AR-GMM samples are better than the original GMM samples. Then, it is tested with a synthetic history-matching problem using the SPE-1 reservoir model with 8 uncertain parameters. The proposed method generates conditional samples that are better than or equivalent to those generated by other methods, e.g., Markov chain Monte Carlo (MCMC) and global search DGN combined with the Randomized Maximum Likelihood (RML) approach, but have a much lower computational cost (by a factor of 5 to 100). Finally, it is applied to a real field reservoir model with synthetic data, having 235 uncertain parameters. A GMM with 27 Gaussian components is constructed to approximate the actual posterior PDF. 105 AR-GMM samples are accepted from the 1000 original GMM samples, and are used to quantify uncertainty of production forecasts. The proposed method is further validated by the fact that production forecasts for all AR-GMM samples are quite consistent with the production data observed after the history matching period.
The newly proposed approach for history matching and uncertainty quantification is quite efficient and robust. The DGN optimization method can efficiently identify multiple local MAP points in parallel. The GMM yields proposal candidates with sufficiently high acceptance ratios for the AR algorithm. Parallelization makes the AR algorithm much more efficient, which further enhances the efficiency of the integrated workflow.
Application of Peres Integral and Gladfelter Deconvolution to Unconventional Reservoirs - The Fractured Basement Case
Authors: Kubota Leonardo 
Published: October 2018

Abstract
This paper prescribes the application of Peres Integral Method (1989) and Gladfelter Deconvolution (1955) to the analysis of pressure-transient tests performed on fractured basement reservoirs. Such type of unconventional porous medium features a matrix that plays no role whatsoever, while a fracture network accounts for both conductivity and storability. Well tests in these unconventional reservoirs might be dominated by noise from wellbore storage effects, which drown out actual reservoir response. We show that the joint application of those methods can effectively purge variable-rate effects from the pressure data and, as a result, unveil reservoir-flow dynamics.