bluuebunny/crossref_metadata_2025_split huggingface dataset:
Technical Review of Tubing Deployed Flow Control Devices at MacKay River
Authors: Gohari Kousha , Becerra Moreno Oscar , Romanova Uliana , O'Hagan Dermot , Mende Anjaneyalu Abilash , Gaviria Fernando 
Published: September 2019

Abstract
Steam Assisted Gravity Drainage (SAGD) is a complex process and often requires more control relative to conventional applications during production operations. Flow Control Devices (FCDs) have been identified as a technology that offers improved efficiency of the process while simplifying the operations. The first FCD completions were installed in SAGD wells in Canada over a decade ago with the intention of improving the steam chamber conformance and reducing the steam-oil ratio (SOR). While it is widely understood that FCD completions, for the most part, have helped achieve the desired uplift for SAGD producers, further optimization could be made on future completion designs and operation strategy by looking at actual performance data from previous installations. The objective of the study was to obtain key design parameters and considerations for future FCD completion designs.
The majority of FCD completions in MacKay River were tubing deployed, installed in previously producing wellbores (retrofit). This study looks at 11 wells that were completed with a Baker Hughes FCDs. The analysis was broken down into 2 segments: production analysis and modelling. Production strategy implemented for each well was taken into account to eliminate variances. The modelling used a combination of steady state simulation (presented in this paper) and numerical simulation (to be presented in part II).
The study showed that TD FCDs improve the performance of SAGD well pairs when implemented in the appropriate candidate wells. An important outcome was the development of a candidate wells’ selection criteria, to ensure the retrofit completion improved performance and did not exacerbate other problems. Furthermore, design consideration were identified to improve the performances of future TD FCD installations.
Productivity Decline: Improved Production Forecasting Through Accurate Representation of Well Damage
Authors: Li Yan , Zaki Karim , Tan Yunhui , Wu Ruiting , Rijken Peggy 
Published: September 2019

Abstract
PI (Productivity Index) degradation is a common issue in many oil fields. To obtain a highly reliable production forecast, it is critical to include well and completion performance in the analysis. A new workflow is developed to assess and incorporate the damage mechanisms at the wellbore, fracture and reservoir into production forecasting. Currently, most reservoir models use a skin factor to represent the combined well damages mechanisms. The skin factor is adjusted based on the user's experience or data analysis instead of physical modeling. In this workflow, a detailed model is built to explicitly simulate the damage mechanisms, assess the dynamic performance of the well and completion with depletion, and generate a physics-based proxy function for reservoir modeling. The new workflow closes the modeling gap in production forecasting and provides insights into which damage mechanisms impact PI degradation.
In the workflow, a detailed model is built, which includes an explicit wellbore, an explicit fracture and the reservoir. Subsurface rock and flow damage mechanisms are represented explicitly in the model. Running the model with an optimization tool, the damage mechanisms’ impact on productivity can be assessed separately or in a combination. A physics-based proxy is generated linking the change in productivity to typical well parameters such as cumulative production, drainage region depletion and drawdown. This proxy is then incorporated into a standard reservoir simulator through the utilization of scripts linking the PI evolution of the well to the typical well parameters stated above. The workflow increases the reliability of generated production forecasts by incorporating the best representation of the near wellbore flow patterns.
By varying the damage mechanism inputs the workflow is capable of history matching and forecasting the observed field behavior. The workflow has been validated for a high permeability, over pressured deep-water reservoir. The history match, PI prediction and damage mechanism analysis are presented in this paper. The new workflow can help assets to: (1) history match and forecast well performance under varying operating conditions; (2) identify the key damage mechanisms which allows for potential mitigation and remediation solutions and; (3) set operational limits that reduce the likelihood of future PI degradation and maintain current performance.
Verification of Autonomous Inflow Control Valve Flow Performance Within Heavy Oil-SAGD Thermal Flow Loop
Authors: Taghavi Soheila , Aakre Haavard , Swaffield Steven , Brough R. Brent 
Published: September 2019

Abstract
One of the main challenges in Steam Assisted Gravity Drainage (SAGD) wells is steam breakthrough in producer wells, which can result in inefficient bitumen recovery due to high Steam Oil Ratio (SOR). Flow Control Devices (FCDs), also known as Inflow Control Devices (ICDs), have been developed for several years to balance the oil inflow along the horizontal wells and consequently delay or mitigate the unwanted fluid breakthrough. The newest generation of FCDs is a truly Autonomous Inflow Control Valve (AICV) which can optimize oil production, reduce SOR and significantly restrict the inflow of unwanted fluids such as water, steam and Non-condensable Gases (NCGs).
This novel AICV design was tested in a full-scale high temperature laboratory flow loop that replicates the downhole operating temperatures, fluid conditions and flow rates of a SAGD production well. The full-scale tests were conducted to determine how the AICV could optimize SAGD production by restricting the production of NCGs and steam and favor the production of oil.
Both single-phase and multi-phase flow performance behavior of the AICV are presented. Furthermore, the results are compared with a conventional passive ICD to illustrate the significant potential of the AICV in enhancing oil production, total recovery and overall project economics.
The results show that the production of lower temperature, relatively high viscosity oil can be increased by approximately 90% for the situation of deploying AICVs. Additionally, gas production is dramatically reduced from approximately 1200 L/h for the ICD, to 180 L/h with the AICV, corresponding to an 85% reduction. These results show that a considerable reduction in steam use is possible by using the AICVs, which would result in reduced energy usage for steam generation, reduced water usage, and reduced greenhouse gas emissions for each barrel of oil produced, thus improving the economics of SAGD projects.
Design and Engineering Implementation of Blowdown System for Cryogenic CO2- NG Pilot Facility
Authors: Md Jalil Abdullah Al , Mat Isa M Faudzi , Rostani Khairul , Othman Nurzatil Aqmar , M Shariff Azmi , Lau Kok Keong , Partoon Behzad , Tay Wee Horng 
Published: September 2019

Abstract
As easy gas resources around the world are depleting; high Carbon Dioxide (CO2) gas fields are thrust into the spotlight to become new candidates for field development. However, the presence of oftentimes sizable Carbon Dioxide contents in the gas reservoir (can be up to 80% volumetric) introduced a huge technical and economic challenges towards the field exploitation.
Over the last few years, several studies have been conducted on cryogenic technologies such as cryogenic distillation and supersonic nozzle in CO2 separation for fields containing more than 40% of CO2. Based on the studies, these new cryogenic technologies have shown to have high potential in separating CO2 from natural gas offshore to be utilized under carbon, capture, storage and utilization (CCUS) project.
The new cryogenic technologies are currently being tested for the proof of concept. Hence, a pilot plant, which is a scaled down version of the technology was developed. One of the major challenges faced during the pilot plant testing is the emergency depressurization philosophy as the process involves CO2 solids handling which is uncommon to the industry standard. Depressurization of high CO2 fluid at cryogenic temperature would lead to possibility of CO2 solids formation, hence potential blockage of process equipment and venting line.
Therefore, this paper will focus on the design of the pressure relieving system of such a facilities. It would also touched on the implementation of the pressure relieving system during the operation of the pilot tests and as well as the tests designed specially to test the pressure relieving system. Finally the paper would give a few proposals on improvements to be made to such system. It is also the ultimate aim of the authors and the team to introduce a new philosophy for Cryogenic CO2 Blowdown system to the process industry.
Oil Saturation in Residual Oil Zones and Its Effect on CO2 WAG Injection Strategies
Authors: Ren Bo , Male Frank , Wang Yanyong , Baqués Vinyet , Duncan Ian , Lake Larry 
Published: September 2019

Abstract
The objectives of this work are to understand the characteristics of oil saturation in residual oil zones (ROZs) and to optimize water alternating gas (WAG) injection strategies. ROZs occur in the Permian Basin and elsewhere, and operators are using CO2 injection for enhanced oil recovery (EOR) in these zones. ROZs are thought to be formed by the flushing effect of regional aquifer flow acting over geological time. Both the magnitude of oil saturation and the spatial distribution of oil differ from water-flooded main pay zones (MPZs).
We conducted flow simulations of CO2 injection into both synthetic and realistic geologic reservoirs to find the optimal injection strategies for several scenarios. These simulations of CO2 injection follow either man-made waterflooding or long-term natural waterflooding. We examined the effects of CO2 injection rates, well patterns, reservoir heterogeneity, and permeability anisotropy on optimal WAG ratios. Optimal is defined as being at minimal net CO2 utilization ratios or maximal oil production rates).
Simulations of CO2 EOR show that the optimal WAG ratio for the ROZs is less than 1 (ratio of injected water and CO2 in reservoir volumes), and it depends, but in qualitatively different ways, upon the well pattern and reservoir heterogeneity. The optimal WAG ratio tends to increase with changing from inverted 9-spot (80-acres) to inverted 5-spot (40-acre) or increasing reservoir heterogeneity. The ratios for ROZs are consistently less than those observed in the same geologic models experiencing CO2 injection after traditional (man-made) waterflooding. This is because the water saturation caused by slow regional aquifer flow (~1ft/yr) differs from that created by traditional waterflooding. In ROZs, water prevails almost everywhere and thus it is less needed to ease CO2 channeling as compared to MPZs.
This work demonstrates that optimal WAG ratios for oil production in ROZs are different from those in traditional MPZs because of oil saturation differences. Thus, commingled CO2 injection into both zones or directly copying WAG injection designs from MPZs to ROZs might not optimize production.
Wettability Studies and Estimation of Capillary Pressure on Heterogeneous Bioturbated Sandstones from Kachchh Basin, India
Authors: Dutta Adityam 
Published: September 2019

Abstract
Reservoir characterisation for modelling and flow simulation is done assuming the homogenous nature of the rock. Heterogeneity is overlooked to prevent occurrences of reserve management complexities. Bioturbated sandstone reservoirs are heterogeneous and prominently found in many petroleum producing basins. Studying the fluid characteristics of these heterogeneous systems is essential, as with changing characters will affect the resulting wettability behaviour. Thus, in a bioturbated heterogeneous reservoir, estimation of the wettability will help in estimating the flow behaviour and possible outcomes of hydrocarbon oil and gas recovery from such formations. With this background, a collective approach has been designed to understand the reservoir behaviour of bioturbated sandstones from Kachchh Basin. The samples are from outcrop, and the analysis includes established standard experimental procedures of core/rock analysis for estimating wettability. The paper explores the experimental analysis of the measuring contract angle in various bioturbated samples. Contact angles of both oil-wet and water-wet cores were measured considering time and gradient factors. Capillary pressure of the various grades of bioturbated sandstones was calculated combining obtained data on contact angle values along with the pore size (radius) and interfacial tension data. The results suggest that the final model can be designed and proposed for the characterisation of bioturbated heterogeneous sandstones using the Capillary pressure behaviour of rocks along with hysteresis trend of imbibition and drainage flows.
Mechanistic Modeling of MEOR as a Sustainable Recovery Technology: Coreflooding Validation, Sensitivity and Field Application
Authors: O. Ansah Eric 
Published: September 2019

Abstract
Globally, most oil fields are on the decline and further production from these fields is addressed to be practical in cost-effectiveness and oil productivity. Most oil companies are adopting two main technologies to address this: artificial intelligence and enhanced oil recovery (EOR). But the cost of some of these EOR methodologies and their subsequent environmental impact is daunting. Herein, the environmental and economic advantage of microbial enhanced oil recovery (MEOR) makes it the point of interest. Since, there is no need to change much-invested technology and infrastructure, amidst complex geology during MEOR application, it is entrusted that MEOR would be the go-to technology for the sustainability of mature fields.
Despite the benefits of MEOR, the absence of a practical numerical simulator for MEOR halts its economic validation and field applicability. Hence, we address this by performing both core and field- scale simulations of MEOR comparing conventional waterflooding. The field scale is a sector model(fluvial sandstone reservoir with 13,440 active grid cells) of a field in Asia - Pacific.
Here we show that pre-flush inorganic ions (Na+ and Ca2+) affect the mineralization of secondary minerals which influences microbe growth. This further influences carboxylation, which is relevant for oil biodegradation. Also, as per the sensitivity analysis: capillary number, residual oil saturation and relative permeability mainly affect MEOR. Secondary oil recovery assessment showed an incremental 6% OOIP for MEOR comparing conventional water flooding. Also, tertiary MEOR application increased the oil recovery by about 4% OOIP over conventional water flooding. It was established that during tertiary recovery, initiating MEOR after 5years of conventional waterflooding is more advantageous contrasting 10 and 15years. Lastly, per probabilistic estimation, MEOR could sustain already water-flooded wells for a set period, say, a 20% frequency of increasing oil recovery by above 20% for 2 additional years as highlighted in this study.
Wettability Alteration of Carbonates with Seawater and Higher Salinity Brines Explored Using a 3D Micromodel
Authors: Ro Grecia 
Published: September 2019

Abstract
We provide experimental evidence of wettability alteration using seawater salinity brine of an oil-wet system composed of a three-dimensional carbonate micromodel, crude oil, and connate-water brine salinity. We designed this procedure as a first step for evaluation of using seawater as an Improved Oil Recovery (IOR) agent. Our innovative design combines two main experimental best practices: micromodels, for repeatable experiments and X-ray computed tomography (CT) as a non-invasive technique for monitoring in situ fluid distribution. Both practices merge into a new three-dimensional micromodel set-up that uses only reservoir species (no high x-ray contrast chemicals).
Wettability alteration plays a key role to improve oil recovery from matrix blocks surrounded by water-invaded fractures in carbonate reservoir rocks. We designed a simple and replicable experimental apparatus and procedure to quantify contact angle distributions inside of porous media with a controlled level of heterogeneity in roughness and mineralogy. This experiment consists of visualizing the in-situ contact angle distribution of the aqueous phase inside a three-dimensional carbonate micromodel. Using Micro Computerized Tomography (MicroCT), we obtained three-dimensional images of fluid distribution with a voxel size of 3.8 microns.
We successfully studied the wettability state after connate water displacement and we also altered wettability of the carbonate porous medium from more oil wet to less water wet conditions. The water contact angle of the ganglia showed a 70% reduction in contact angle from an oil-wet to a water-wet system using an approximate seawater salinity and a 63% reduction in contact angle in the case of a full synthetic seawater. The initial average contact angles were 140° and 142° for the two solutions, respectively. After EOR seawater flooding, the average contact angle declined to 44° and 51°, respectively.
New Approaches of Porosity-Permeability Estimations and Quality Factor Q Characterization based on Sonic Velocity, Critical Porosity, and Rock Typing
Authors: Akbar Muhammad Nur 
Published: September 2019

Abstract
Many investigations have been discussed and it is a well-recognized fact that sonic wave velocity is not only influenced by its rock matrix and the fluids occupying the pores but also by the pore architecture details of the rock bulk. This situation still brings a lack of understanding, and this study is purposed to clearly explain how acoustic velocity and quality factor correlate with porosity, permeability and details internal pore structure in porous rocks.
This study employs 67 sandstone and 120 carbonate core samples collected from several countries in Europe, Australia, Asia, and USA. The measured values are available for porosity ϕ, permeability k, clay content Vcl, compressional velocity Vp, and quality factor Qp in saturated and pressurized conditions. Then, a proposed method is developed by re-arrangement on Kozeny equation to perform rock typing based on pore structure similarity which called as pore geometry-structure (PGS). The proposed rock typing method allows investigating the influential primary factors that control acoustic velocity and quality factor. Besides that, basic rock physics equations for sonic velocity and critical porosity concepts are also involved and derived to obtain a new solution to predict porosity and permeability.
At least eight rock groups are established from rock typing with its Kozeny constant. This constant is a product of pore shape factor Fs and tortuosity τ. Then, the relations of velocity and quality factor versus porosity, permeability, pore geometry (k/ϕ)0.5, and pore structure (k/ϕ3) are constructed. One can find that each relation among the rock groups of each lithology is clearly separated and produce high correlations. Velocity and quality factor tend to be high with an increase in Kozeny constant. However, for a given porosity for all the groups, velocity and quality factor increase remarkably with a decrease in Kozeny constant. These all mean that velocity and quality factor increase with either an increase in the complexity of pore systems or, at the same pore complexity, a decrease in specific internal surface area. On the other hand, each rock group for both sandstone and carbonate has its critical porosity and it strongly correlates with velocity and porosity. Finally, critical porosity becomes a specific property of rock groups having similar pore geometry and structure.
As a novelty, the empirical equations are derived to estimate compressional velocity and quality factor based on petrophysical parameters. Furthermore, this study also establishes empirical equations for predicting porosity and permeability by using compressional wave velocity, critical porosity, and PGS rock typing.
Review of Nanoparticle Applications in Petroleum Engineering: Recent Advancements and Challenges
Authors: Chauhan Prithvi Singh 
Published: September 2019

Abstract
This review is based on latest application of nanoparticles in hydraulic fracturing, and their feasibility as compared to other conventional methods. Focusing on technical, economic, mechanisms and direction of future research. Current status and advancement give a promising future application by using unique properties of nanomaterials such as small sizes, stability, magnetic properties and surface area which are yet to be exploited to full potential. Nano materials can be inculcated in drilling in all forms. From acting as additives in drilling mud there by enhancing density, gel breaking strength, viscosity, acting as a proppant, cross linking agent etc.
There are certain problems which are difficult to overcome using macro and micro type additives due to limitations in physical, chemical and environmental characteristics. Hence, the scientists are looking for such smart fluids which can overcome these limitations. Compared to their parent materials, nanoparticles can be modified physically, chemically, electrically, thermally, thermodynamic properties and interaction potential of nanomaterial. However more investment, work and pilot projects are required to understand properties of nanomaterials at reservoir temperature and pressure.
Nanomaterials such as aluminium oxide, zinc oxide, copper oxide, silicon dioxide, low cost carbon nanotubes, fly ash nanoparticles in unconventional reservoirs need to be further researched. Moreover, focus should be put on economic analysis, performance at reservoir conditions, cross linking and agglomeration properties, wettability alterations, interfacial tensions properties. The enhanced hydrocarbon recovery from unconventional reservoirs through wettability alterations and interfacial tension decrement by nanomaterials and combined use of fracturing fluid system comprising of VES, foams, proppants gives a promising future application.