bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on Oppositely Charged Polymer and Surfactant Mixture for Enhancing Oil Production
Authors: Xu Limin , Han Ming , Zhang Xuan , Fuseni Alhasan 
Published: October 2019

Abstract
Polymer-surfactant mixtures in aqueous solutions present unique rheological and interfacial properties that promote their applications in chemical flooding. The objective of this study is to investigate the interaction between anionic polyacrylamides and cationic surfactants in different temperature and salinity conditions and the potential application of the polymer-surfactant mixtures in carbonate reservoirs. Cationic surfactants were selected owing to low adsorption on carbonate rocks. Compatibility tests of polymer-surfactant mixtures were conducted in brine with different salinities to study the interaction between anionic polymers and cationic surfactants in the presence of salts. The effect of cationic surfactants on polymer viscosity at different temperatures was investigated.
The compatibility of the mixtures of the cationic surfactants and the anionic polymers was significantly improved in high salinity injection water (with a total dissolved solid of 57,670 mg/L), compared with the compatibility in deionized water. This is attributed to the shielding of polymer and surfactant charges by the salts, which diminishes the electrostatic interaction between the chemicals. Rheological measurements indicated that the polymer viscosity increased in the presence of the cationic surfactant CAS-S or CAS-B. This effect was decreased at 90˚C. Other cationic surfactant CAS-1 or CAS-3 slightly increased the polymer viscosity at 25˚C and significantly decreased the viscosity at 90˚C. These observations can be explained based on the surfactants self-assembly. At room temperature, CAS-1 and CAS-3 form spherical micelles while CAS-S and CAS-B form wormlike micelles. The entanglement of the polymers with wormlike micelles explains the observed viscosity enhancement. At 90˚C, wormlike micelles became shorter which weakens this viscosity enhancement effect. In conclusion, the charges and self-assembly structures of surfactants play an important role in the performance of polymer-surfactant mixtures that should be taken into account in the design of optimal formulations. This work provides the insight of interaction between anionic polymers and cationic surfactants with different self-assembly structures for the potential application in improving oil production.
The Animated Reservoir Plumbing: A Time-Lapse Integrated Reservoir Description Schematic
Authors: Hadidi Shahab , Wahaibi Ahmed , Sabahi Mohammed , Aghbari Hilal , Saaidi Abdulhamid , Suwannathatsa Sakharin , Mahajan Sandeep , Miotto Alberto 
Published: October 2019

Abstract
The reservoir plumbing is a conceptual integrated reservoir description diagram that combines the reservoir architecture, fluid fill and fluid dynamics. The objective of the reservoir plumbing is to highlight the main features in the reservoir that might influence oil and water movements and possible subsurface realizations. The resultant schematic(s) will aid in identifying main uncertainties impacting hydrocarbon development, revealing reservoir data gaps, flagging any bypassed oil and assisting in the revision of the current development or any additional development opportunity. The animated reservoir plumbing is taking the concept to a new level where the reservoir history is presented in sequential events starting from the deposition setting prior initial charge and up to the current state.
The inputs into each time step of the reservoir plumbing are the initial reservoir properties and development activities that had an influence on hydrocarbon and water movements. The required properties are listed with the source of information (seismic data, core, logs, pressure data, PVT, etc) including the degree of uncertainty and their impact on hydrocarbon recovery.
Based on the gathered information, interpretations are translated into conceptual diagrams and presented in snapshots which include;
the initial depositional setting before initial hydrocarbon charge, hydrocarbon migration, any structural or diagenetic changes occurring after hydrocarbon charge that might influence fluid fill or movement, any additional hydrocarbon migration events and subsequent structural changes - if any - and, possible fluid movement paths (both oil and water) resulting from development wells.
Different versions of the reservoir plumbing might be required to represent alternative subsurface realizations.
The animated reservoir plumbing was created for a carbonate field of the Lower Shuaiba and Kharaib Formations in the Sultanate of Oman at the beginning of the Field Development Plan update. It was used to decide the modelling approach, identify improvements in the development strategy, recognise potentially bypassed oil and acquire additional data ahead of modelling to prove the concept of this bypassed oil.
Uncertainty Assessment of Hydrocarbon in Place With Geological Models Satisfying Gravity-Capillary Equilibrium
Authors: Guérillot Dominique , Bruyelle Jérémie 
Published: October 2019

Abstract
In a reservoir, gravity forces lead fluids to stratify according to their density, and transitions zones appear around contacts (water-oil and gas-oil contacts). These transitions zones are gradual variations of saturation of each phase. These saturations are often generated using geostatistical methods leading to errors in the calculations of fluid in place. They must be calculated in a physical manner using capillary pressure curves associated with lithofacies. In this paper, a physical volumetric method to calculate the hydrocarbon in place with a high-resolution geological model is used on data coming from a synthetic field: the Brugge field. The uncertainties on hydrocarbons in place are evaluated using the Monte-Carlo method.
Impact of Fines Type on Gas Flow Using 3D Micro-Computed Tomography
Authors: Al-Raoush Riyadh , Hannun Jamal , Jarrar Zaher , Alshibli Khalid , Jung Jongwon 
Published: October 2019

AbstractMethane hydrates are promising unconventional energy source with natural reserves above 1,000 Trillion m3. Hydrates are found in saturated sandy sediments, where multi-phase flow of gas takes place through sediment's pores, physical phenomenon at pore-scale controls flow properties. Gas permeability is highly affected by fines type due to migration, clogging and bridging reducing gas flow. Fines migration has huge influence on storage and recovery of oil and gas resources from the subsurface. There is a knowledge gap of fines effects on gas production from sandy sediments, especially at pore-scale, in homogenous porous media. Therefore, there is a need to model and quantify fines impact on multi-phase flow using 3D reconstruction to better understand gas recovery systems.The pores in which gas flow through are reconstructed using 3D synchrotron X-ray micro- computed tomography images of sand sediments, at resolution of 3.89 micron per voxel. Sand was mixed with fines and deposited in test columns. Kaolinite and Montmorillonite clay fine particles were added in different columns, each system was scanned at four stages with varied saturations of brine as CO2 gas was injected in real time while scanning. Images were processed for 3D visualization, segmentation and quantification for each system. Effects of swelling and non-swelling clays were characterized to understand multi-phase flow of gas at pore-scale.Findings revealed that fines accumulate at sand-brine and brine-gas interfaces. As fines concentration increased, gas percolation decreased. Further increase in fines concentrations resulted in blocking local gas flow causing pressure variations enough to create fractures that allows gas to escape and percolation to rise. In unconsolidated media, the pore space geometry will change due to sand grains movements. At high concentrations, different fines types produce altered gas flow regimes, Kaolinite which is non-swelling clay resulted in fractures while montmorillonite which is swelling resulted in detached gas ganglia entrapping the gas. Generally, increasing fines reduces gas percolation and further injection of gas reduced permeability. The finds herein are critical in understanding the impact of fines migration during gas flow in sand, they can be applied to characterizing and predicting two phase properties of unconsolidated sediments.The qualitative and quantitative findings achieved in this work in 3D, agree with other observations in recent literature on 2D micromodels. Understanding the fluid physics in homogenous sand systems is an essential step to quantify fines impact on heterogeneous rock systems. The work helps in improving flow characterizing at pore scale, to mitigate to formation damage problem and advance reservoirs upscaling capabilities.
Development of an Integrated Approach to Improve Heavy Oil Recovery From a Low-Permeability Carbonate Reservoir
Authors: Al-Murayri Mohammed Taha , Kamal Dawood S. , Al-Tameemi Naser , Li Zhitao , Delshad Mojdeh 
Published: October 2019

AbstractUmm Gudair/Abduliyah Tayarat reservoir is a challenging EOR target because of its high oil viscosity, low permeability, and carbonate mineralogy. A previous feasibility study indicated that a hybrid EOR thermal and chemical method combined with IOR techniques could produce significant amount of oil from this reservoir. The objective of this study was to identify the most viable reservoir-specific EOR/IOR approach taking into account techno-economic considerations.With the latest well logging data, production history, and petrophysical measurements, the Tayarat reservoir simulation model was revisited. Consequently, this simulation model was updated and calibrated to reflect field and lab observations. In addition, lab tests that demonstrated good transport and oil recovery performances of a selected polymer in low permeability reservoir cores were modeled to provide parameters for field-scale scoping simulations. Sensitivity studies were conducted to evaluate the effects of injection temperature, viscous fingering, well configuration, etc. A simple economic analysis was conducted to demonstrate the economic benefits of the proposed hybrid EOR/IOR method.Calibrated by history matching the actual production data, the Tayarat reservoir model included a barrier zone that would prevent influx from a bottom aquifer. A better match was obtained by assuming that the reservoir is strongly water wet, which is consistent with the latest laboratory imbibition and contact angle measurements. Reservoir transmissibility was increased to represent possible fractures/microfractures in the carbonate reservoir. Scoping simulations based on a selected sweet spot of the Tayarat reservoir showed that primary recovery was ineffective due to the lack of a bottom aquifer, and waterflood recovered significantly more oil. A hybrid thermal/chemical EOR process was more effective when a preflush of hot water was considered to heat up a portion of the reservoir ahead of chemical injection. When viscous fingering was neglected, oil recovery could be erroneously as high as 50% more compared to the case when viscous fingering was modeled. Simulation results showed that about 19% of OOIP could be recovered using the hot waterflood followed by hot polymer flood, i.e. about 130% higher than conventional waterflood corresponding to a water cut of 95%. The chemical cost for incremental oil produced with our most promising approach was $10/bbl of incremental oil.This integrated laboratory and simulation study should provide meaningful insights into tackling challenging low permeability and/or heavy oil carbonate reservoir using novel chemical EOR techniques.
Tight Carbonate Reservoir Characterization and Complition Optimization Using Magnetic Resonance in Horizontal Well, Umm-Gudair Field, West Kuwait
Authors: FawzyFahmy Mahmoud , SinghaRay Dipak , Zekraoui Mohamed , Ghioca Monica , Qutainah Riyad 
Published: October 2019

AbstractMiddle Marrat resrervoir of Jurrasic age is a tight carbonate reservoir with vertical and horizontal heterogeneous properities. The well placement over deep elonogted anticline with steep dips, geosteering and lowering of production liner are challenging, therefore the field is being developed using horizontal wells cutting across multiple reservoir layers to maximize reservoir contact and driangeThe low clay content in Marrat reservoirs gives low gamma ray counts, which makes the identification of reservoir layers identification difficult. In addition, the high-resistivity responses from hydrocarbon-bearing pay-zones and from the tight layers make the identification of the reservoir sweet spots difficult as well. Slim-hole magnetic resonance (NMR) logging was deployed in wash-down mode for identifying reservoir sweet-spots as a lithology-independent porosity and formation fluid characterization tool.Magnetic resonance was acquired with dual wait time enabled T2 polarization to differentiate between moveable water and hydrocarbons. After acquisition, the standard deliverables were porosity, the effective porosity ratio, and the permeability index to evaluate the rock qualities. Porosity was divided into clay-bound water (CBW), bulk-volume irreducible (BVI) and bulk-volume moveable (BVM). Rock quality was interpreted and classified based on efftective porosity and permeability index ratios. The ratio where a steeper gradient was interpreted as high flow zones, a gentle gradient as low flow zones, and a flat gradient was considered as tight baffle zones.Based on the MR flow units and fluid types (CBW, BVI and BVM), the drilled interval was classified into six compartments of high flow, one compartment of low flow, and five tight baffle zones. Accordingly, the perforation plan was optimized to fit the high flow units only. Comparing to the conventional log analysis, NMR excluded approximately 1000 ft of non-productive reservoirs, leading to a significant cost savings (250,000 USD) in perforationand production optimization.The well was drilled with a distance-to-bed boundary tool; however, enormous potential exists to use this slim MR tool as a non-radioactive sourceless solution for geosteering through reservoir sweet spots while delivering wells that are more productive safely.
Two-Phase Fluid Flow Behaviour of Minagish Ooilte Dynamic Rock Types and Their Impact on Reservoir Management Practices
Authors: Dipankar Dutta , Nasser Al-Khalifa , Raj Kishore Prasad , Tahani Al-Rashidi , Meshari Al-Subaihi , Meshari Al-Zamanan , Noura Al-Kudhur , Aurora Diya , Roth Sven , Blunt Martin 
Published: October 2019

Abstract
Nine capillary constrained pore facies have been used to characterize the static rock types of the Minagish Oolite reservoir. However, this classification resulted poor history match on dynamic platform. An in-depth review indicated that two representative textural facies - connected vuggy limestone and fractured limestone - were not captured in the model due to either non-availability of suitable plug samples or respective bed thickness below log resolution. To resolve this issue, high resolution X-ray tomographic whole core data was generated in order to capture continuous pore network records along a 337ft core section.
Using CT based pore typing, six representative dynamic rock types were created with 10 cm vertical resolution. Out of these, two are vug/fracture dominated high permeability type and three are matrix pore dominated rock types. One is tight and non-reservoir facies. The high-permeability connected vuggy or fractured limestone samples show a wide range of pore size. Under weakly oil-wet conditions, the relative permeabilities of these rock types indicate unfavorable waterflood performance and only the oil from the vugs or fractures could be recovered in a full field dynamic setting.
In case of grainstones with separate vug porosity, the non-connected vugs are connected through the macropore system. After drainage of the macropore and vugs, the micropores get invaded, which contributes well to the changes in saturation profile. In fractured limestone, in particular, the connected fractures control the fluid flow behavior, which has extremely low waterflood relative permeability cross-over saturation of 0.11. This indicates a very unfavorable oil recovery where essentially only the oil in the fractures can be displaced.
Wettability variations from strongly oil-wet to mixed-wet conditions had little impact on likely recovery and the overall assessment of waterflood behavior. The scanning curves, representing waterflooding a transition zone, again displayed similar behavior, in that the flow was still controlled by the preferential displacement of oil from the larger connected pore space.
High permeability vuggy limestones and low permeability mudstones, when captured within the dynamic model provide better history match for the last 60 years of production and thus, improved production forecasts for upcoming wells. Identification of perforation intervals avoiding the high permeability zones, selective plug back, choke back in production wells and deciding the rate and suitable intervals for injection are some of the important tools used for well-based production optimization.
Development of New Rheology Modifier for Invert Emulsion Drilling Fluids
Authors: Wagle Vikrant , AlYami Abdullah , Alanqari Khawlah , Alkhalaf Sara 
Published: October 2019

Abstract
It is of prime importance for a drilling fluid to have good and optimal rheology in order to achieve good hole-cleaning and have good barite sag resistance. Invert emulsion drilling fluids with organoclay as a viscosifier sometimes fail to maintain sufficient rheology during drilling due to the thermal degradation of organoclay with time and temperature. Thus, there was a need to develop a drilling fluid with optimal rheology sufficient to give good hole cleaning and barite sag resistance in high temperature and pressure conditions.
This paper describes the formulation of invert emulsion drilling fluids formulated with a synergistic rheology modifier combination comprising of two different additives viz. rheo1 and rheo2. Invert emulsion fluids formulated with either rheo1 or rheo2 did not show good and optimal rheology required for successful drilling. However, the synergistic effect of these two additives rheo1 and rheo2 resulted in fluids with low PV and enhanced yield point and low end rheology thereby increasing their capacity for better hole-cleaning and barite-sag resistance.
The effectiveness of this rheology modifier combination was shown by formulating 68pcf low density, 90pcf medium density and 120pcf high density invert emulsion drilling fluids. The 68pcf, 90pcf and 120pcf fluids were hot rolled at 250°F, 300°F and 325°F respectively. Rheology of the 120pcf invert emulsion fluid was measured across high temperature and pressure range. The paper also describes the contamination and static aging studies of 90pcf and 120pcf fluids at 300°F and 325°F respectively.
68pcf, 90pcf and 120pcf invert emulsion drilling fluids formulated with the novel rheology modifier combination of rheo1 and rheo2 showed optimal rheology and low HTHP fluid loss. Static aging studies of 90pcf and 120pcf fluids at 300°F and 325°F respectively showed that the fluids were resistant to barite sag. Contamination studies of 90pcf fluid showed that the contaminants have minimal effect on the rheology and filtration properties of the invert emulsion fluid. HTHP rheology of the 90pcf invert emulsion fluid shows consistent rheology across high temperatures and pressures. The paper thus demonstrates the superior performance of the rheology modifier combination to achieve good rheological and filtration properties.
Green Transition by Green Refrigerants for HVAC System
Authors: Mohammad Shakeel , Al-Ajmi Obaid Mohamamed 
Published: October 2019

Abstract
Recently, the Climate Change has become a major challenge across the globe. It is disrupting national economies, costing us dearly today and will cost even more tomorrow. Therefore, ‘2015 Paris Climate Change’ marked a historic turning point as it arrived at a universal agreement on climate to keep global warming below 2 °C.
HVAC (Heating, Ventilating & Air conditioning) system in general and its refrigerants (heat transfer media) in particular, has significantly impact Green House Gases (GHG) and climate change. Such systems contribute to GHG emission in terms of direct non-green refrigerant emissions and indirect CO2 emissions associated with the energy needed to operate / run the HVAC system. Hence, HVAC industry has been constantly supporting the global efforts for Green Transition.
The two measures of environmental effect are Ozone Depletion Potential (ODP) and Global Warming Potential (GWP). ODP represents the relative ability of a refrigerant (CFC & HCFC), used in Air conditioning System, to destroy stratospheric ozone molecules when released to the atmosphere and thereby increasing the UV radiation reaching the earth. CFCs (Chloro Fluoro Carbons like R 11) have the highest ODP, HCFCs (Hydro Chloro Fluoro Carbons like R 22) have comparatively less and HFCs (no Chlorine Content, like R 410A) have zero ODP.
The Montreal protocol stipulates that HCFCs (like R 22) are scheduled to be phased out by 2040 (likely to be advanced to 2030) in Article 5 countries like Middle East and others. In non-article 5 countries (developed countries), the environmentally friendly substitutes for HCFCs are being developed and used. Currently Middle East is under extended phase out schedule for R 22 till 2030. The local regulatory bodies (like EPA, MEW–Kuwait) have not yet published any recommendations for its environmentally substitute.
Air conditioning & Refrigeration system is extensively used for Control Rooms, Electrical Substations and Offices etc. within KOC premises. This paper provides a detailed study of ‘Refrigerants Progression’ towards Green transition while providing excellent performance benefits. It also provides KOC best practices considering challenges & implementation while taking into account the merits and limitations of Refrigerant(s) for "KOC Air-conditioning system". It is worth broadening our choice of HVAC and applicable Green Refrigerant.
This paper also discusses the steps being taken by KOC towards adopting "Green Refrigerants" to improve KOC's image in protecting our fragile environment, in line with the Paris COP 21Climate Change agreement.