bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of Zones of Abnormal Pressures and Determination of the Mechanical Properties of the Rock Through Pseudo-Sonic and Pseudo-Density Logs in Conventional and Unconventional Reservoirs
Authors: González José W , Valdez Ronny , Torres Juan , Medina Francisco 
Published: October 2018

Abstract
The objective of the work is to identify zones of abnormal pressures and determine the dynamic mechanical properties of the rock in wells without information of sonic and density logs. In the area of study, geomechanical problems have been detected in intermediate hole sections that make it difficult for drilling operations, thus generating non-productive times. Density log (ρb), compressional sonic log (Δtc) and shear sonic log (Δts) are essential to attack this problem and provide possible solutions.
To determine the pseudo-sonics logs, it was necessary to modify the correlation of L.Y. Faust (1951), introducing a third variable, the clay volume, it was called Faust Modified Correlation. The pseudo-density log was obtained from the G.H.F. Gardner adjusted correlation (1974). The zones of abnormal pressures were identified by comparing the normal compaction train of the sonic log (Δtcn) with the compressional sonic log (Δtc). And finally the dynamic mechanical properties of the rock were determined such as Poisson's ratio (n), Shear modulus (μ), Bulk modulus (K), Young's modulus (E) and Bulk compressibility (C).
The Faust modified correlation showed excellent results of compresional sonic logs, obtaining a correlation coefficient of 93%. The Gardner adjusted correlation as a function of the P wave velocity obtained good results of density logs, with a correlation coefficient of 94%. The zones of abnormal pressures were identified towards the Miocene base with an average pore pressure of 9.17 ppg. In the Pliocene and Miocene high Poisson's ratio was determined that varies between 0.28 and 0.36, and low Young's modulus between 0.85 and 5 Mpsi, this indicates that the rocks are deformed more easily. In the Eocene and Cretaceous, low Poisson's ratio was determined between 0.21 and 0.27, and high Young's modulus between 6.1 and 10 Mpsi, this indicates that the rocks do not easily deform.
In addition, the velocity models of the P wave and S wave (VP and VS) were simplified through graphical methods, where VP is a function of the Bulk modulus (K) and Shear modulus (μ), while VS is a function of the Shear modulus (μ). From these models, cubes of Lamé's parameters (λ, μ), elastic properties and S wave velocity were determined using the velocity cube of the RMS compressional wave of seismic as input data to generate cubes of clay volume and fluid saturation with the purpose of looking for opportunities in exploration areas.
Smart Water Flooding: An Economic Evaluation and Optimization
Authors: Sadeed Ahmed , Tariq Zeeshan , Janjua Anneq Nasir , Asad Abdul , Hossain M. Enamul 
Published: October 2018

Abstract
Smart water (or low salinity water) flooding has been an emerging technology in the petroleum industry since last two decades. Low capital cost and operating expenses of this flooding make it attractive for the petroleum industry. This paper examines the economic feasibility of the injection of smart water and compares with other conventional water flooding techniques. Optimization has also been done with different dilution schemes through particle swarm optimization.
This study analyzes the effect of smart water and sequential dilution of injected sea water through reservoir modeling. A three-dimensional black oil reservoir model is developed by using ECLIPSE 100. In addition, this study presents the economic feasibility of the injection of smart water and compares with other conventional water flooding techniques. The study is divided into four cases: i) oil is produced without water flooding, ii) formation water is injected in the reservoir, iii) sea water is injected in the reservoir, and iv) water injection is taken place by sequential dilution of high salinity water. In each case, economic evaluation is completed by calculating the costs and revenues generated by water injection, and oil prod uction.
The results show that sea water injection did not give additional oil recovery compared to formation water injection for our case. However, additional results show that sequential dilution flood recovers more oil than sea water and formation water injection. Moreover, five main parameters are optimized such as number of cycles of different salinities, duration of various cycles, salinity values for different cycles, injection rate and production rate. Optimization results show even better results than sequential dilution. The optimization also shows that the additional oil recovery is achieved when the dilution sequence is altered. This outcome illustrates that increased oil recovery is not only dependent on step wise reduction of sea water salinity but also with the variation of dilution pattern.
This paper presents a novel technique for the reservoir engineers to study smart water flooding with different perspective. Sequential dilution has been an acceptable technique for increasing oil recovery. However, change of the dilution pattern could be a good alternative and thus provides a cost-effective technique as compared to sequential dilution.
State of the Art on Porosity and Permeability Hysteresis: Useful Techniques for Hydrocarbon Recovery
Authors: Elhaj Murtada A. , Barri Assad , Hashan Mahamudul , Hossain M. Enamul 
Published: October 2018

Abstract
Recently, experimental and mathematical studies helped researchers to investigate and understand the fundamentals of hysteresis behavior in rock properties. Porosity and permeability are the two of the most important rock properties that are used to characterize the ability to store and transport hydrocarbons in porous media. Hysteresis plays an essential role in porous media and depends on several physical and mechanical properties. In petroleum and geomechanics engineering, understanding hysteresis behavior of porosity and permeability is required for hydrocarbon production plan. Numerous mathematical and experimental studies have been conducted to understand the effect of hysteresis on rock properties, and how they can play a role in improving the productivity of well. Therefore, it is essential to study hysteresis of rock properties, especially porosity and permeability.
This paper presents a comprehensive review and critical analysis of porosity and permeability hysteresis, experimental and mathematical studies. In this paper, an effort to bring together much of this information into one source is highlighted for a better understanding of reservoir performance and description. Moreover, this paper tracks the current development on hysteresis and gives some insight for future studies on the application of hysteresis on rock properties.
This article offers an extensive review and critical analysis on different kinds of hysteresis phenomenon of permeability and porosity such as porosity-permeability vs. net stress hysteresis, and porosity-permeability vs. temperature hysteresis. The review also includes mathematical models that are developed to represent this phenomenon as well as procedures of the experimental works and the devices used in the experimental studies. The finding concludes with highlighting some missing concepts in existing models and experimental procedures for porosity and permeability hysteresis. In the literature, no attempt is made to refer and review the hysteresis despite numerous works have been accomplished. Based on this fact, this article considers one of a kind and it is the first attempt to provide a complete and comprehensive review of porosity and permeability hysteresis.
This research will help in understanding the impact of a hysteresis effect in petroleum engineering, and the production strategies of hydrocarbons specifically in low-permeability reservoirs such as shale, tight sandstone, and tight carbonates.
Non-Archie Rock Characterization Using Triple Porosity Conductivity Model in Carbonate Reservoirs
Authors: Tariq Zeeshan , Mahmoud Mohamed , Al-Yousef Hasan , Khan Mohammad Rasheed 
Published: October 2018

Abstract
Rocks can be classified as "Archie" or "non-Archie" types depending on the relationship between pore geometry, resistivity, and porosity. Carbonate reservoirs have complex pore networks and Archie's law cannot be applied to estimate the water saturation in these types of reservoirs. Several models for complicated porosity systems have been proposed, to determine the water saturation based on the well logs and laboratory experimental data. A mathematical model (such as Archie's equation) which appropriately describes the conduction of a specific rock depends on the conduction mechanism. The conduction mechanism, in turn, is determined by pore geometry as well as nongeometric factors such as wettability and the presence of conductive or surface conductive minerals. In general, the measured (Resistivity Index) RI curves cannot be described by an Archie's law and the measurements at very low saturation are often a key observation to confirm a non-Archie behavior.
A large variety of shapes can be observed. These shapes can be explained qualitatively and quantitatively using two model's dual porosity conductivity model and triple porosity conductivity model (DPC and TPC) in which the different porosity systems are connected either in series or in parallel, or a combination of both. Hence, only two of three adjustable parameters are needed to model the experimental results.
In this work, a triple porosity systems saturation models are presented. This model can be used to determine the water saturation based on combined NMR/log data, NMR measurements are used to obtain the volume fraction of each pore network (Macro, Meso and Micro pores). Moreover, the factors affecting the electrical parameters are thoroughly investigated, such as; cementation factor, lithology constant, and saturation exponents. The relations between these parameters and the petrophysical properties are explained. A sensitivity analysis is performed to show the effect of each parameter on the resistivity index (RI) curves. A simple procedure is proposed to estimate the conductivity ratio between each of the two and three networks based on the lab data, using this approach the ratio of saturation exponents can be determined, which further reduces the number parameters needed to be fitted to one, and consequently improving the model's accuracy. The proposed model for triple porosity systems has been validated by employing published investigational data which had RI versus water saturation curves; the result of this validation produces adequate match between actual data and those predicted using the new model.. The new model for Non-Archie rock has been developed which can help petrophysicist to find the water saturation based on resistivity properties in and triple porosity systems with greater level of certainty.
Wireless Sensor Network System for Coastal Area Monitoring
Authors: Idachaba Francis Enejo 
Published: October 2018

Abstract
Coastal areas are very sensitive and vital areas as the provide habitation for the aquatic life in those regions. These areas contain a diverse array of aquatic life with rare and indigenous species which are delicate and can go into extinction if not protected. The advent of offshore and shallow water oil and gas processing in these areas exposes the aquatic life to the hazards associated with these oil and gas processes. The most critical of these hazards in oil spills. Oil spills can be defined as a release of oil into the environment due to a loss of containment of the transport medium. The spills can vary in volume and as such trigger different response mechanisms. Spills from pinhole leaks or leaks due to crude oil discharges from transport vessels are often difficult to detect and these discharges if not quickly detected and contained has the capacity to impact and destroy both the plant and aquatic life in the coastal areas. This work presents the design of a real time wireless sensor network system for monitoring the aquatic environment in coastal areas. It is implemented using sensors immersed in the aquatic environments. These sensors monitor the chemicals and the PH values of the coastal areas and send alerts in real time to the monitoring centers whenever the threshold for any of the monitored contaminants are exceeded. The system is designed to utilize the available communication technology to transmit the alerts to the control center. This system will enable the relevant authorities have a real time information on the chemical contaminants in their coastal areas and also provide alerts in the event of the dumping of hazardous waste products and enable the deployment of the appropriate response mechanisms to protect both the plant and aquatic life of these areas.
Corrosion Measurement in Oil and Gas Pipeline: A Mathematical Model Approach
Authors: Nwachukwu Ifeanyi Bobby 
Published: October 2018

Abstract
Corrosion is a major flow assurance problem in the oil and gas industry, various researches have been carried out to prevent or mitigate the effect of corrosion in the industry. This study considered corrosion measurement in acidic system (CO2, H2S, CO2-H2S Systems) four basic corrosion measurement models; Electrochemical model, De-Waard Model, George De-Waard Nesic Model and the Norsok Thermal/Hydraulic model, to calculate the corrosion rate and severity level of oil or gas pipeline. The models calculate the corrosion rate of the pipeline in mm/year, thereby making provision for easy estimation of oil or gas pipeline life thus proffers solutions to corrosion problems in time and prevents sudden damage to pipelines. Based on the Field Data used the NHT model shows a Severity level of 3, average severity index of 3.527462 and average absolute deviation(%AAD) of 29.1474% whereas the GDN model shows a severity level of 3, average severity index of 3.7325 and %AAD of 53.161%, the Electrochemical Model (ECM) shows a severity level of 2 and Severity index 3.047079 and %AAD of 70.7653% and De Waard a Severity level of 4 and a Severity Index 4.646465 and %AAD of 95.3401. Which ranks Norsok Thermal Hydraulic Model first in the list followed by George De-Waard Nesic Model, and then the Electrochemical model and lastly the De-Waard Model.
Estimation of Horizontal-Well Productivity Loss Caused by Formation Damage on the Basis of Numerical Modeling and Laboratory-Testing Data
Authors: Vodorezov Dmitry D. 
Published: October 2018

Summary
This paper presents a new numerical model of inflow to a well with a zone of damaged permeability. It is built on the principle of dividing the wellbore and damaged permeability zone into numerous segments. Simultaneous work of the segments is modeled with the method of velocity-potential theory. The model is applicable for wellbores of different trajectories including horizontal and multilateral wells. The model is focused on the extended application of results obtained during laboratory core testing that include a return-permeability (RP) profile of the core and cleanup parameters. The developed solution includes the effects of anisotropy, reservoir-boundary conditions, and a nonuniform distribution of formation damage in both radial and axial directions. The paper presents the new approach to include depth-variable distribution of damage in skin-factor models. The approach provides for the evaluation of pressure drop in a depth-variable damage zone by the resulting permeability that is defined by flow regime. Laboratory-obtained overall core permeability is associated with a linear flow, and when applied to a zone near the wellbore with radial or elliptic flow, it causes an error because of the depth-variable distribution of damage. The provided numerical simulations show that the impact of this factor on horizontal-well productivity is significant. The developed model is compared with existing analytical solutions of Furui et al. (2002) (FZH) and Frick and Economides (1993) (FE) for the case of a horizontal well with a cone-shaped damaged zone. The results show that a skin-factor transformation originally proposed by Renard and Dupuy (1991) for a case of a uniformly damaged well can be used successfully for the referred-to analytical solutions, which makes them applicable for wells with an elliptic drainage area. In this paper, we also suggest an approach whereby we relate the characteristics of the cleanup of the region near the wellbore to laboratory-testing conditions.
Rheological Demonstration of Heavy Oil Viscosity Reduction by NiO/SiO2 Nanoparticles-Assisted Ultrasound Cavitation
Authors: Pinzón Daniel Montes 
Published: October 2018

Abstract
The increasing world energy demand has derived in the consumption of conventional sources of energy, leading to a rise in non-conventional resources such as heavy oils (HO). Nevertheless, the HO physicochemical properties such as high viscosity, are related to significant operational issues in production and transport processes. Thus, the main objective of this study is the HO viscosity reduction through a novel cracking reactions method prompted by an ultrasound cavitation technique assisted with nickel oxide nanoparticles functionalized over nanoparticulated silica (SiNi) as catalysts, and water as a hydrogen donor for enhancing the cracking reactions, fomenting the conversion of the crude oil heavy compounds (asphaltenes) into lighter sub-components. An HO with 17.02% of asphaltenes content was used for carrying out the tests. Along the study, there were identified several viscosity reduction mechanisms related with asphaltenes adsorption onto SiNi nanoparticles surface affecting the fluid internal structure, as well as the reduction of the crude oil asphaltenes content due to its conversion into lighter components. These mechanisms were widely explained by a phenomenological approach through rheological behavior measurements and modeling, which also provide a better understanding of the treatment effect in the HO mobility and an increased transport capacity. The viscosity measurements were realized upon nanoparticles and gasoline addition, and ultrasound cavitation separately. The ultrasound cavitation submission time was evaluated, with better results as the exposure time increased. The effect of nanoparticles concentration was also assessed, obtaining high degrees of viscosity reduction with nanoparticles dosages = 2000 mg/L. After the complete treatment application, an asphaltenes content reduction greater than 15% was observed with a viscosity reduction degree (VRD) up to 50% at a fixed shear rate of 20 s-1. This study should open a wider landscape about the use of nanotechnology for improving the production and transport of heavy oils.
Integrated Resource Estimation and Field Development Workflow for Unconventional Reservoirs Using Reservoir Simulation and Economic Analysis Tools: A Case Study from a Shale Well in Saudi Arabia
Authors: Alsadoun Reem 
Published: October 2018

Abstract
Unlike conventional reservoirs, unconventional shale reservoirs have significantly lower permeabilities and therefore exhibit transient behavior for longer periods of time, creating uncertainty in reservoir parameters during simulation. Currently, there is no standard industry technique to assess gas deliverability in unconventional reservoirs. The aim of this paper is to present a workflow to calculate Estimated Ultimate Recovery (EUR) and optimize field development that was applied for a multistage fractured horizontal well in a shale play in Saudi Arabia. The workflow starts with using a combination of Decline Curve Analysis (DCA) and Rate Transient Analysis (RTA) methods performed with reservoir simulation software. To achieve an initial estimate of the EUR, we employed the following decline curve models: Stretched Exponential and Duong. After establishing a range of EUR values, a history match was carried out by varying porosity, permeability, stage number, fracture half-length, lateral length, and the Stimulated Reservoir Volume (SRV). We then performed a numerical simulation, where reservoir properties and compeletion pamaters were altered until the simulated data matched the production data. We then performed a sensitivity analysis on the results where the reservoir and well parameters were changed and compared against the cumulative gas production to assess the influence of each parameter on well deliverability while considering the economics of such sensitivities. The economic analysis was carried out by calculating the Net Present Value (NPV), which is dependent on the gas rate, shrinkage, and price, and stimulation and operation costs. The economic evaluation was then carried out by sensitizing different completion parameters, which were then determined for subsequent wells in the area. The results of the sensitivity analysis indicate that increasing the fracture half-length has the most significant impact on the gas production when compared to other completion parameters such as the number of fractured stages. The proposed workflow can be used to determine the EUR and the optimum field development plan for an unconventional shale well in Saudi Arabia to maximize gas production while reducing costs. The workflow can be also used, through the suggested tools, to improve our understanding of the behavior of unconventional gas plays
Evaluating Nonequilibrium Solute Transport through Four Soils of Pakistan using a HYDRUS Model and Nonparametric Indices
Authors: Rukh Shah , Akhtar Mohammad S. , Mehmood Ayaz , Hoghooghi Nahal , Radcliffe David E. 
Published: October 2018

Core IdeasSoil structure with a large volume of small macropores has greater preferential transport.Nonparametric indices differentiated the soils with preferential transport.Chemical non‐equilibrium under unsaturated flow diminished fast in coarse blocky soil.Leaching experiments in soil under different saturations show inconsistent results regarding preferential flow, and therefore further investigations are needed. The comparative degree of non‐equilibrium flow of chloride (Cl) was evaluated using replicated large intact columns taken from two alluvial (Rawal, Typic Hapludalfs and Kotli, Entic Haplusterts) and two loess (Guliana, Udic Haplustalfs and Mansehra, Typic Hapludalfs) soils that differed in structure below 20 cm depth. Lithium chloride (3.5 mM) was pulsed with constant flows generated by heads 10, −10, −40 mm water; Cl breakthroughs were fit into a physical non‐equilibrium model with no sorption; and lithium (Li) breakthroughs (measured for the two loess soils) were fit into a physical and chemical non‐equilibrium model using HYDRUS‐1D. The Cl breakthrough curves were highly skewed, with immobile water contents in the range of 0.10 to 0.39 cm3cm–3, indicating that physical nonequilibrium occurred under saturated flow as well as under unsaturated conditions. The nonparametric indicators (i.e., apparent dispersivity, the piston flow to Cl velocity ratio, the holdback factor, and the arrival time of the first 5% of Cl) indicated a greater strength of preferential flow in the Rawal and Guliana soils, which had more well‐connected pores than the Kotli and Mansehra soils, which had fewer macropores and dense aggregates. Lithium breakthrough occurred under chemical non‐equilibrium, which diminished with desaturation, especially in the Mansehra soil. There were two sources of preferential flow: (i) macropore flow under saturated conditions and (ii) bypass flow in the matrix due to regions of disconnected water under unsaturated conditions. The study results will help understand leaching potential of agro‐chemicals in similar soils.