bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real-Time Fluid Characterization Using Advanced Gas Analysis in Hith and Gotnia Formations
Authors: Peres Jose , Mukherjee Pritish , Dashti Jalal , Mushnuri Sudhakar , Al-Qattan Faisal , Al-Bader Mishari , Al-Kandari Jassim , Al-Awadi Mishari , Reitsma Mariel , Watts Jon 
Published: November 2018

Abstract
The Hith and Gotnia Formations in Kuwait were considered to only be acting as seals for the early Jurassic hydrocarbon bearing reservoirs. However, recent hydrocarbon discovery within the Gotnia Formation has proven that they have reservoir potential as well. Due to High Pressure-High Temperature (HPHT) conditions of these formations, casing is set immediately after drilling, thus limiting open hole data acquisition. To overcome this problem we deployed a single mass spectrometry service for advanced gas analysis to understand and characterize the fluid variations within the Hith and Gotnia Formations.
Two mass spectrometers, for gas in and gas out detection, were connected to constant volume degassers in the suction pit and shaker house, respectively. First, the dynamic oil based mud (OBM) discriminator differentiated OBM contamination and subsequently the unique ‘real-time’ algorithms quantified concentrations of formation hydrocarbons.
The formations under evaluation were divided into 3 major geochemical zones based on acquired gas data. These geochemical zones were marked by changes in mud gas response and were closely linked to lithological properties, each lithology type having a distinct gas signature. The Hith Formation consists of thinly interbedded anhydrite and limestone and comprises the first geochemical zone. With low gas response, gas ratios point to a potential oil fluid type although the formation is likely unproductive due to low permeability and high water content. The four halite intervals within the Gotnia Formation were grouped together as the second geochemical zone, having no production potential due to their low porosity and permeability. They behave as a seal to the hydrocarbons in the interbedded anhydrite-limestone intervals. The three anhydrite plus limestone intervals within the Gotnia Formation belong to the third geochemical zone. Comparison of the oil signatures in these intervals revealed a decrease in fluid density from top to bottom. The different fluid density within each interval and the sealing efficiency of the interbedded halite suggest that there is no direct fluid communication between the individual anhydrite cycles. This paper covers in details the response and interpretation of the gas signatures in each zone.
Effects of Formation Properties and Treatment Parameters on Hydraulic Fracture Geometry in Poro-Viscoelasticity Shale Gas Reservoirs Using Cohesive Zone Method in a 3D Model
Authors: Suo Yu , Chen Zhixi , Rahman Sheik , Xu Wenjun 
Published: November 2018

Abstract
Hydraulic fracturing is a significant way to improve the productivity of the unconventional reservoir with low permeability and porosity. Current hydraulic fracturing simulation models are mostly based on poro-elastic theory. However, for rocks such as shale, the viscoelastic feature has been observed in both field investigations and laboratory experiments. This paper presents a 3D numerical model for fracture propagation in visco-elastic shale gas formations using ABAQUS platform. The cohesive elements based on damage mechanics were adopted to simulate the initiation and propagation of hydraulic fractures. The model was used to investigate formation properties and treatment parameters on fracture geometry, especially the fracture behaviour when entering into the barrier formations. It is found that higher treatment pressure is required to initiate and propagate the hydraulic fracture and the fracture is wider but shorter in poro-viscoelastic formation comparing to poro-elastic formation. The higher differential in-situ stress, tensile strength and Young modulus in barrier formations and lower fracturing fluid injection rate and lower fracturing fluid viscosity have positive effect on the controlling of fracture vertical growth and restricting hydraulic fracture within the pay zone. Results of this study will provide the industry a better understanding of hydraulic fracture behaviour in shale gas formations.
Using CHARM Modelling to Decide the use and Discharge of Surfactant at an Offshore EOR Project
Authors: Chai Ching Hsia Ivy , Shafie Nur Anisah , Razali Norzafirah , A Manap Arif Azhan , Salleh Intan Khalida 
Published: November 2018

Abstract
The application chemicals such as surfactants for Enhanced Oil Recovery (EOR) has caught the attention of various stakeholders especially regulators and operators - raising concerns of the impact of these chemicals to the ocean when they are back-produced. The current approach in mitigating the toxicity at production is the dilution of produced fluids to a lower concentration before disposal to sea. However, how confident are we that EOR chemicals do not cause environmental impact to marine life? Due diligence conducted showed that there are no environmental regulations or guidelines in Malaysia for the application of EOR chemicals at an offshore platform. For this reason, our team refers to the strictest of regulation for chemicals' use and discharge for an offshore environment used at the North/Norwegian Sea, adopting all qualification criteria from Harmonized Ocean Chemical Notification Format (HOCNF), of the OSPAR Harmonised Mandatory Control System (HMCS), developed through the OSPAR Decision 2000/2. HOCNF ranks chemical products according to Hazard Quotient (HQ), calculated using the Chemical Hazard and Risk Management (CHARM) model. CHARM is a set of rules to determine the risk and extent of surfactant formulation's movement in the ocean - a vital decision making tool to determine if EOR chemicals are safe for use and overboard discharge. This paper describes the ‘environmental-friendliness’ of a newly developed surfactant formulation which will be applied in a Water-Alternating-Gas (WAG) operation at an offshore field in Malaysia using CHARM. First, a comprehensive review of the components of the formulation was conducted, leading to sound selection and/or synthesis of chemistries that confers good environmental properties i.e. non- or low toxicity, persistency, bioaccumulation, with high biodegradability. Next was to determine the degree of toxicity of the formulation at three trophic levels. Using the lowest acute toxicity value, we apply this value to the CHARM model to calculate the dilution of the formulation 500 m radius from the point of discharge - given the expected adsorption, application concentration, and the volume ratio between squeeze vs. produced water. Whether CHARM is exhaustive to decide if the surfactant formulation can be discharged overboard is still being debated. Many argued that it is the responsibility of the chemical manufacturer or product inventor to select or synthesize chemistries with good ecotoxicity properties in the first place. Product innovation has to be aware on new regulation(s) e.g. the banning on the use of a chemical currently used in manufacturing so that the company develops an alternative ahead of its competitors. In the operator's viewpoint, even if the model indicates that the chemical pose a low hazard, physicochemical parameters of the produced fluids has to be monitored beyond the pilot implementation period.
Improved Characterization of Transition Zones in Carbonate Reservoir by Modern Digital Imaging Technique
Authors: Sun Huafeng , Belhaj Hadi , Bera Achinta 
Published: November 2018

Abstract
Transition zone (TZ) containing a large amount of oil plays a key role in a carbonate reservoir. Its characterization is challenging because it is difficult to define top and thickness of the transition zone and it may contain many kinds of rock types differently affecting the fluid flow behavior. Routine core analysis (RCA) and special core analysis (SCAL) can be used to study for characterizaiton and modeling of TZs, but these data can rarely be used to obtain the details of the pore structure governing the rock properties. In recent years, the digital imaging technique has made great progress, because the rock microstructures can be directly imaged by using modern digital imaging technique such as thin sections (TS), scanning electron microscope (SEM) images and X-Ray computed tomography (XCT) scans. This paper focuses on the application of digital imaging technique for characterization of TZs in carbonate reservoirs located within the Middle East region. The experimental data and digital imaging data are used to study the rock samples of TZ. The results show that: 1) the rock properties of TZ samples can be accurately predicted by using digital imaging technique; 2) the petrography and diagenesis of TZ are well studied; 3) the carbonate rocks are qualitatively and quantitatively classified into three types: matrix, fractured and vuggy; 4) digital imaging technique, generally, proves to be a powerful tool for characterization of TZs in carbonate reservoirs.
Cyclone Type Autonomous Inflow Control Device for Water and Gas Control: Simulation-Driven Design
Authors: Chochua Gocha , Rudic Aleksandar , Kumar Amrendra , Mainy Aurelien , Woiceshyn Glenn 
Published: November 2018

Abstract
Horizontal wells are considered superior to vertical and deviated wells because they increase reservoir contact; however, they can cone unwanted fluids (gas, water) causing reduced oil recovery and early well abandonment. Inflow Control Devices (ICDs) are typically installed along the completion string to delay coning and restrict water/gas influx. Once the coning occurs, conventional ICDs, such as channels and orifices, were found to be inadequate in choking back the unwanted fluids. Thus, new types of "autonomous" ICDs, or AICDs, were developed that choke back unwanted fluids more than conventional ICDs. Conversely, such AICDs have limitations related to bulkiness, moving parts, wellsite adjustability, flow performance predictability, and erosion.
To overcome these limitations, a new AICD, operating on a principle of a cyclone, was developed by a synergy of the latest numerical technologies, such as Computational Fluid Dynamics (CFD) utilizing a high-fidelity Large Eddy Simulation (LES) turbulence model, and Design of Experiments (DOE) techniques. This CFD-driven design optimization involved utilization of high-performance computing (HPC) coupled with experimental validation. A DOE matrix of CFD analyses runs was performed to identify a geometry that would generate significantly higher pressure drop for water and gas than for oil.
Early multiphase testing on a prototype device validated the concept, and CFD was used to improve the understanding of the operating principle and hence the design. CFD was further used to extrapolate the flow performance to a wider range of operating conditions. An expanded flow performance map and the use of non-dimensional parameters led to the development of a mechanistic AICD performance model which further enhanced our understanding of AICDs and allowed reservoir software programs to evaluate the production performance of wells with AICDs versus wells with conventional ICDs or no inflow control. The overall result is the new cyclonic AICD presented herein which is: 1) relatively compact, 2) without moving parts, 3) erosion resistant, 4) superior in multiphase performance, 5) easily adjustable at the wellsite with many settings, 6) accurately modeled with CFD, and 7) easy to incorporate into state-of-the-art reservoir simulation models.
Asset Management of Wells and Facilities Through Integration of Monitoring and Geomechanical Modeling for a Field with Active Subsidence in Sultanate of Oman
Authors: Mahajan Sandeep , Stammeijer Jan , Mukhaini Hamed , Azri Saif , Rahmoune Rachid , Aamri Mohammed , Tarmizi Ikhsan 
Published: November 2018

Abstract
One of the PDO's largest producing fields in Oman consists of three stacked reservoir formations, two of which are currently producing while deeper reservoirs are being considered for development. The shallowest reservoir (~ 900 m depth) is a highly compacting carbonate gas reservoir under depletion, whereas the intermediate reservoir Shuaiba is an oil-bearing reservoir under water flood. The deeper reservoirs are oil and gas bearing located in the Sudair and Khuff formations.
Interpretation of 3D seismic data shows a major NE/SW and NW/SE fault system in all 3 reservoirs. Depletion in the shallow gas reservoir, which exhibits pore collapsing response on depletion, has induced surface subsidence which is active and expected to reach about 2.4 m at the end of field life. Subsurface deformations and induced stress changes have resulted in subset of the faults (NE/SW) to reactivate, causing seismic tremors, occasionally felt at surface.
Ongoing surface subsidence has resulted in some damage to surface facilities and subsurface well integrity issues. Furthermore, fault reactivation and/or loss of well integrity may induce leakage pathways for reservoir fluids to cross flow between reservoirs or to shallow aquifers. PDO has implemented an extensive monitoring program supported by parallel 3D geomechanical modeling studies, to manage ongoing field development whist mitigating the risks.
Extensive monitoring efforts using a variety of techniques are in place since 1999. Frequent InSAR satellite data measures surface subsidence with such high accuracy and resolution that local zones of higher deformation can be reliably identified and flagged. Continuous GPS data acquisition in a few places throughout the field allows for detailed temporal assessment of subsidence and forms the basis for predictions of total subsidence at end of field life. Periodic in-well compaction monitoring data provides insights in elastic and non-elastic deformation at reservoir layer scale, which is compared against core compressibility data. Continuous microseismic monitoring in a dozen or more observation wells highlights geomechanically active faults in the main reservoir, overburden and underburden, thereby identifying potential risk zones on a near-24/7 basis.
All of this data is used both for well and facilities management, and for providing calibration data for geomechanical models. Results provide clarity on future surface subsidence and differential settlement, which helps to identify facilities with potential risk. The project teams are provided with reliable predictions of surface subsidence throughout the field to ensure the current design tolerance is adequate for integrity of the facilities until the end of field life. This paper presents modeling workflow and calibration with monitoring data related to the geomechanical assessment.
Low Cost CO2 Capture: Dream or Reality?
Authors: Seif El Nasr Adel Ahmed , Geuzebroek Frank Haiko , Singh Prachi 
Published: November 2018

Abstract
Carbon capture and Storage is one of the major pathways to reduce carbon dioxide emission. Over the years, the success of this technology has been relatively limited. Reasons for this include lack of acceptance of storage, but also a lack of economic feasibility. In many cases, projects need to be funded through subsidies or are justified on the basis of use for enhanced oil recovery. Meanwhile an enormous effort has been placed into lowering the cost of capture. Many R&D programs have set the target to reduce cost from typically 50 $/ton to 25 $/ton, while even now this kind of reductions have not been realized, to the contrary there has been an increase in reported cost.
This paper addresses the background of the situation. It gives a literature overview of different technologies and the associated cost. A cost analysis is made of the different components in a CO2 capture plant. Comparison is made for the different technologies for post, pre- and oxy-combustion. The reasons for the high cost is analyzed and it is shown that no silver bullets exist. Several smart technologies are currently in development and the latest insights are given in how these technologies can reduce cost. A few studies are given that show why these technologies could not fulfill the initial expectations.
The results show that there is a tendency that advantages of technology solutions are often off-set by disadvantages that are not foreseen at the early Research stages, often because the new systems are more complicated than the state-of-the-art. This includes engineering cost for mitigate these dis advantages. An example is the use of smart solvents with phase change involved. This process may lead to lower OPEX due to lower energy consumption, but cost is increased by the higher cost for doing the separation or for keeping the solvents from leaving the solvent.
Novel Approaches for Remaining Hydrocarbon Saturation Evaluation Through Interpretation of Multi-Detector Pulsed Neutron Logs
Authors: Xian Hong , Anaevune Austin , Anijekwu Chinedu , Nayagawa Mbursa , Egwim Stella Ihuoma , Longe Victor , Ezechukwu Nduka , Lee Robert , Hulea Iulian 
Published: November 2018

Abstract
Novel interpretation approaches for remaining hydrocarbon saturation evaluation were developed from our study and presented in this paper. Innovative power law relationships and algorithms are used for evaluating oil saturation from Carbon/Oxygen (C/O) logs and gas saturation from capture-to-inelastic count rate ratios, based on the principle of the modern multi-detector pulsed neutron tool responses and the total porosity rock model. C/O log interpretation parameters are determined from the crossplot of near detector against far detector C/O logs, and gas saturation interpretation parameters are obtained from the crossplot of near detector versus far detector capture-to-inelastic count rate ratios. An alternative fixed response line method is proposed based on a simplified C/O log response rock model. Integrated interpretation is applied through the post processing combining the interpretations of C/O logs and capture-to-inelastic count rate ratios, to derive the final result.
The developed approaches have been applied to wells from Nigeria Delta and North Sea. Example results have successfully demonstrated greater advantages over the traditional methodologies. These new approaches have markedly reduced the saturation uncertainty related to wellbore effects, especially for wells with complex well completions and borehole fluid phase change. These results were subsequently useful information for the dynamic reservoir simulation models.
Energy Savings of Amine Sweetening Process through Lean and Rich Vapor Compression Approaches
Authors: Hatmi Khalid Al , Mashrafi As'ad Al , Balushi Sa'Ud Al , Al-Kalbani Haitham , Al-Battashi Mundhir , Shaikh Mohammed 
Published: November 2018

Abstract
The natural gas demand for energy production has increased in the last decades and is forecasted to further increase in the future. According to IEA energy outlook report 2008, approximately 40% of proven natural gas reserves are acidic (i.e. contains H2S and CO2). Hence, the need to capture associated contaminants of acidic gases to meet health, environmental, integrity and product specifications with affordable techniques will continue to be a challenge. Amine sweetening process is considered as one of the most acid gas removal techniques being used around the world due to its flexible operation, high removal efficiency and its design maturity. However, energy requirement around amine process has been always an area of a concern for all new and existing units. The top energy consumer is the regenerator re-boiler. Optimization of energy requirement around Amine plant becomes an important exercise for most operating companies to minimize its expenditures either during design stage or operation stage and achieve carbon emission target.
The aim of this study is to examine the effectiveness of two debottlenecking approaches namely Lean Vapor Compression (LVC) and Rich Vapor Compression (RVC) to minimize energy consumption around Amine units. These two approaches are considered to be the most promising in reducing the reboiler duty. These debottlenecking approaches involve modification of standard conventional process flow scheme with modified process flow scheme to enhance heat integration and regeneration efficiencies.
The two approaches have been applied on two different amine sweetening units in Sultanate of Oman with MDEA and MDEA-PZ solvents. ProMax process simulation software has been utilized to perform advanced thermodynamics model which has been initially validated by real field data.
Unlike most of published studies, the study has been conducted using models validated by real field data including different solvents and operating conditions as a base case. Additionally, the study focuses in pre-combustion amine based CO2 and H2S capture processes. By applying the Lean Vapor Compression approach, 40-50% reduction in re-boiler duty was achieved. For Rich Vapor Compression approach, saving of 10-11% has been achieved with considerable changes in amine circulation rate and stripper operating pressure.
Conformance Improvement for Ultra-High-Temperature Reservoir: A Comparative Study between Hydrostable and Conventional Preformed Particle Gel
Authors: Long Yifu , Yu Bowen , Zhu Changqian 
Published: November 2018

Abstract
Conformance improvement for ultra-high-temperature (130 °C) reservoirs is challenging due to the poor thermostability of conventional preformed particle gel (CPPG). To overcome the defect of thermal degradation, a novel hydrostable PPG (HT-PPG) was developed using the high-temperature tolerant crosslinker. In this work, a comparative study between the HT-PPG and CPPG has been presented in respects of their swelling behaviors, rheology properties and thermal stabilities. Particle swelling behaviors and viscoelasticities were firstly assessed in ambient. Using the swollen particles, a long-term aging at 130 °C underwent during which the physical status was monitored through high pressure vials (HPV). Furthermore, characterizations involved Scanning Electron Microscope (SEM) and Fourier Transform-Infrared Spectroscopy (FT-IR) were performed for both virgin and aged specimen. Thereby, an observation of gel microstructures and elucidation upon bonds or functional groups were provided. In addition to aging tests, we deployed the Differential Scanning Calorimetry (DSC) to investigate the inflection temperature as another indicator of particle thermostability. Attributed to the hydrostable crosslinker, the HT-PPG withstood 130 °C for at least 90 d. It was found that the HT-PPG effectively maintained its particulate shape, whereas, the CPPG completely degraded after 3-d aging. The HT-PPG maintained 28.8% of its initial storage modulus (G′). On the contrary, the normalized elasticity (G′/G0‘) of CPPG was only 0.43%. The SEM morphologies illustrated HT-PPG kept its rigid microstructure even after 90-d aging, while indicated destruction within CPPG network. According to FT-IR characterization, the decomposition of pristine crosslinker, N,N′-Methylenebisacrylamide in CPPG may account for its instability. DSC measurements furtherly demonstrated the favorability of HT-PPG in which HT-PPG exhibited a higher inflection temperature of 133.1 °C, however, CPPG only had an inflection temperature of 127.7 °C. This work turned out the novel HT-PPG could withstand ultra-high-temperature (130 °C) for more than 90 d, maintaining its particulate shape and viscoelasticity. This a durable plugging agent was notably superior to the CPPG, offering a candidate material for the conformance improvement in ultra-high-temperature reservoirs.