bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Integrated Workflow of IOR/EOR Assessment in Oil Reservoirs
Authors: Chen Peila , Balasubramanian Sriram , Bose Sushanta , Alzahabi Ahmed , Thakur Ganesh 
Published: April 2018

Abstract
This paper presents a comprehensive workflow to screen, rank and evaluate improved and enhanced oil recovery (IOR/EOR) opportunities for given reservoirs. This multidisciplinary workflow was applied to multiple oil reservoirs, aiming to improve volumetric sweep and recover bypassed oil.
This comprehensive screening workflow integrates the static and dynamic reservoir conditions, and fully couples with geological and geophysical characterization. Firstly, a parametric screening and ranking for various IOR/EOR techniques for the target reservoirs are performed. Secondly, an advanced EOR screening process incorporating the evaluation of geological framework, facies distribution, flow barrier, reservoir production performance and other key reservoir rock and fluid characteristics is applied. The impacts of critical parameters to production performance are rigorously investigated, including various diagnostic plots of waterflood.
The oil reservoirs were pre-screened by oil initially in place (STOIIP) and current production rate to screen out the less attractive reservoirs for EOR. Five top-ranked reservoirs were evaluated by integrating geological characteristics (static) and dynamic reservoir indicators. Diagnostic plots such as water oil ratio (WOR), oil rate, number of active oil producers, GOR, reservoir pressure, water injection and production profiles were analyzed to investigate the reservoir performance. Through this workflow, additional opportunities were identified to increase production and/or extend the reservoir life. The reservoir screening for IOR/EOR assessment revealed a high side opportunity of adding over 5.2 MMBOE of recovery through effective reservoir management. A portfolio of most attractive EOR targets was generated for decision making by higher management.
The integrated IOR/EOR screening workflow, evolved from practical field experience, is beneficial for revitalizing mature waterfloods, effective reservoir management, recovering bypassed oil, and more importantly the design and implementation of suitable EOR pilots.
Application of Real-time Video Streaming and Analytics to Breakdown Rig Connection Process
Authors: Hegde Chiranth , Awan Omar , Wiemers Tim 
Published: April 2018

Invisible lost time (ILT) has been estimated to contribute significantly to well construction costs. Reduction of drilling connection time can lead to significant savings, especially in offshore drilling projects. The overall time of a drilling connection can easily be measured using conventional sensors on the rig. However, to gain further insight into the source of operational inefficiencies it is beneficial to breakdown the overall drilling connection process into smaller sub-processes and quantify the time spent doing each. Current sensor technology does not allow us to easily measure these sub-processes on the rig. In this paper, we outline a deep learning-based computer vision method to analyze and measure such sub-processes within the overall drilling connection process using a real-time video feed.
Video of the drilling connections is streamed in real-time using a novel IT framework. In a proof of concept exercise, we applied image recognition techniques to enable us to breakdown and classify the sub-processes during the drilling connections. Convolutional neural networks (CNNs) - a deep learning algorithm - are used to analyze these video images frame by frame to identify rig activities.
The workflow includes an analytics pipeline to capture video on the rig, transfer of data to the office, video recognition analysis, tabulation of results, and delivery of this result to a graphical interface for cognitive analytics. We performed experiments wherein CNNs were used on the video images to diagnose rig activities with good accuracy. Incorporating the temporal information using a recurrent network has been shown to further improve analysis accuracy.
The described workflow is a suggested method for automating the detection of inefficiencies on drilling rigs using rig floor video and machine learning. For the demonstration case, we successfully analyzed video captured on an offshore rig and derived high value useful information using machine learning. This video analysis information can be further combined with conventional drilling sensor data to boost accuracy to identify and confirm rig activities and to quantify invisible lost time during each connection. The presented techniques demonstrate the potential of video analytics as a reliable, low-cost means to effectively "micro-analyze" various rig operations with the aim to identify and replicate best composite performance.
A Practical Approach to Evaluate Acoustic and Flow Induced Fatigue of Piping Systems
Authors: Chen Quan , Vinayan Vimal , Vrijland Ronald 
Published: April 2018

Abstract
Piping systems having flow discontinuities like bends, tees, reducers and valves can experience acoustic induced vibration (AIV) or flow induced vibration (FIV) due to internal pressure fluctuations (acoustic or turbulent flow sources of excitation). The excitation may range from 20 Hz to 5000 Hz depending on the pipe geometry and flow characteristics. At such frequencies, excessive vibration can cause fatigue-induced failure of the piping system if not designed properly. In some extreme cases, failure may occur in a matter of days or even hours. This paper proposes a practical frequency domain based finite element analysis (FEA) approach/design-tool to calculate the fatigue damage of piping systems due to FIV or AIV.
For a FIV analysis, the two key steps that can be identified in this approach are: (1) the development of a transfer function, and (2) the generation of a pressure fluctuation spectrum over the frequency range of interest. The transfer function defines the relationship between the stress range (∆σ) and a unit pressure fluctuation (∆p) that is used to calculate the fatigue damage. It is assumed that the stress range reaches a maximum when the internal acoustic pressure spatial distribution completely coincides with the natural mode shape of the pipe system. Harmonic analysis is performed to obtain the maximum stress range at each natural frequency of the piping system. From the transfer function and pressure fluctuation spectrum, a stress range spectrum can be calculated. Assuming a Gaussian fluctuating pressure distribution, a Rayleigh distribution is expected for the stress range. The fatigue damage can be calculated using a closed-form solution with an associated S-N curve. A typical tee-joint in a pipe spool will be examined to illustrate the procedure. The proposed procedure can be modified for an AIV analysis specifically, which is not presented here.
Use of Magnetorheological Fluids for Pressure Drop Generation
Authors: Estrada John , Akbari Babak , Nielsen Garrett 
Published: April 2018

Abstract
The magnetorheological fluids (MRF), or magnetic field responsive fluids, are a combination of magnetically polarizable particles in a carrier fluid. This type of fluid has the ability to modify their rheological properties under the influence of a magnetic field. The generation of a tunable pressure drop could have the potential to controlling fluid losses while drilling and cementing in narrow operating windows and to provide a tunable fluid barrier that could work as a packer. Using the reduced form of the Navier-Stokes equation and a model to estimate the yield stress of the fluid based on the magnetic field strength, it is possible to determine the pressure drop caused by the fluid behavior.
Effects of Nanoclay on the Rheological Properties and Resistivity of Synthetic Based Drilling Fluids under High Temperature
Authors: Pan Dongmei , Vipulanandan C. , Amani Niousha , Reddy Sai Anudeep , Chockalingam Chella Ganapathy 
Published: April 2018

Abstract
In this study, synthetic based drilling fluids (SBF) were developed for high temperature applications and modified using nanoclay to improve the sensing properties for monitoring. The major constituents of drilling fluids were fatty acid methyl esters, surfactant and water. The ratios of synthetic based fluid to water (S/W) ratios of the SBF were 50/50 and 70/30. The temperature was varied from 25°C to 85°C. The nanoclay concentration was varied up to 1% by the weight of the SBF to modify the rheological properties and the sensing electrical resistivity of the SBF. The effect nanoclay on the rheological properties and electrical resistivity of the SBF was investigated. PV of SBF (50/50) was increased 100% and 286% at 25°C and 85°C respectively and additional of NC reduced the effect of temperature on the PV of SBF. Hyperbolic model has been suggested for modeling the rheological behavior of the SBF to predict the ultimate shear stress. Adding 1% of NC affected the rheological properties by increasing yield point and ultimate shear stress of the SBF with S/W ratios of 50/50 and 70/30. The electrical resistivity of the drilling fluid with and without nanoclay decreased with the increase in the temperature. The results also showed that even 1% nanoclay decreased the electrical resistivity of the drilling fluid 30.2%. This clear indication of the sensitivity of electrical resistivity to the nanoclay contents and the electrical resistivity is a good tool for quality control for the SBF.
Case Study of an Offshore Operation Conducted with a Fit-for-Purpose Abandonment System
Authors: Canny Steven A , Olstad Delaney Michael 
Published: April 2018

Abstract
Traditional late-stage abandonment operations can utilize equipment originally designed for drilling a well. However, innovative new technologies have been developed which far better meet the unique needs of intervention and abandonment work. The effective application of these systems in the oil and gas industry has resulted in both significant cost savings and an increased standard of safety. Additionally, Operators have realized that an integrated project solution from a single source is integral to completing the job scope in a competent and effective manner. This paper examines the successes of a fit-for-purpose system currently working in the Gulf of Mexico which is specifically designed to both conduct late-stage intervention and abandonment project, and focus on safety while reducing overall operational expenditures.
To effectively address the market, a new method for completing workovers and abandonment operations was needed. Subsequently, a system was designed which incorporates capabilities associated with costly Jack Up rigs along with the quick mobilization and set up of a crane assisted rigless unit. This solution has been utilized in offshore campaigns that include all phases of abandonment operations including well diagnostics, reservoir isolation, tubular retrieval, fishing, section milling, and conductor recovery
The case study will highlight the versatility and adaptability of the system which provides an integrated solution package to the client. The system which includes a pulling and jacking unit also includes all ancillary equipment necessary to efficiently intervene and permanently abandon offshore wells. The case study will discuss the project parameters, examine the operations, and review the lessons learned from a multiple well project on an offshore platform in the Gulf of Mexico.
Safety Distances of Packers for Deep-Water Tubing-Conveyed Perforating
Authors: Deng Qiao , Zhang Hui , Li Jun , Dong Jian , Wang Hao , Hou Xuejun 
Published: April 2018

Abstract
The technologies of high density and high charge perforator are widely used in the perforation jobs of deep-water wells, resulting in a large increase of impact loads in the wellbore. Determining the safety distances between the packers and the perforating gun is a critical step for developing completion designs of deep-water. This paper examines the processes of pressure wave generation, attenuation and reflection propagating through the completion fluid during wellbore perforation and develops a calculation model to formulate safety distances of the packers to protect the non-perforated wellbore. A calculating model containing an unknown function is established, which is used to solve the safety distances of packers and a mathematical model based on numerical simulation results is proposed to predict the peak pressure on the perforating gun, which can evaluate the sensitivity of peak pressure to changes under different conditions of perforation. The complete calculating model for determining the safety distances of packers is finally created. The results of case study show that the predicted peak pressure by the model is accurate, within 10% of measured values by a pressure sensor installed at the bottom of the perforating gun during a well completion job within the South China Sea. This calculating model indicates that the attenuation law of the pressure wave propagation in the completion fluid basically accords with the exponential attenuation mode, which is verified by the data of underwater explosion experiment. The number of perforating bullet, charge per hole, tubing length, formation pressure and wellbore pressure are important factors of the safety distances. According to the numerical simulation results of the field example, the shock absorber has the optimal installation position, which the ratio R0/R=0.6 being the best shock absorption effect can be achieved. This study proposes a novel method for the safety distances design of packers and the location of the absorber is optimized, which has important significance to provide guidance for the design of deep-water perforating operations and to improve security.
Modeling Subsea Gas Release to Atmospheric Gas Dispersion Cloud
Authors: White Charles , Pétrié François , Rousse Benjamin 
Published: April 2018

A new methodology has been developed and tested by the authors to model gas dispersion efficiently from a subsea pipeline gas release. The methodology was applied to two practical cases: a 1′ diameter hole and a full pipe rupture in 100m water depth. The objective of the study was to develop a calculation methodology to simulate gas cloud propagation above the sea surface from a subsea gas release. The simulation includes modeling the gas concentration in air to determine if the concentration reaches critical levels.
The methodology utilizes three steps:
Calculation of gas discharge rate;
Calculation of subsea gas jet and plume utilizing an analytical model;
Calculation of gas dispersion in air with specialized CFD software.
This paper presents a case study performed for each calculation step with the objective of increasing the calculation efficiency compared to a typical full CFD methodology.
This methodology has shown promise in providing a simple, quick, and cost-effective solution for these safety analyses. The main efficiency is realized modeling the subsea jet and plume using fundamental equations. The subsea model and analysis determine the gas content repartition at sea surface as an input for the gas dispersion analysis. An analytical model was utilized, with some simplifying assumptions, leading to a significant reduction in calculation time. The analytical model used has been validated with underwater gas plume experiments. The reduction in calculation time can allow for an increased number of simulation and sensitivities of the study, leading to a better understanding of the main sizing parameters involved.
As a conclusion, the limit of the present approach and its validity domain are discussed based on the models used and the assumptions performed during the calculations. Further developments can be anticipated (e.g., larger water depth application or validation of high gas discharge rates based on experiments to evaluate the limitation of the assumptions).
An Example in the Use of Performance-Based Engineering for Offshore Shallow Foundations Overlying Liquefiable Sand
Authors: Sancio Rodolfo B. 
Published: April 2018

Abstract
Geohazards affecting offshore facilities are typically mitigated through avoidance. However, as stated by Cauquil (2014), exploration and production activities are moving to more complex and deeper geo-environmental contexts, and recent projects have shown that it may not be possible to avoid the geohazard and its impact area. Therefore, facilities in these fields must be developed using a design that can overcome the effects of the hazard.
If present, seismically induced geohazards (e.g., seabed settling due to liquefaction) can be mitigated by placing facilities on deep foundations that penetrate through liquefiable layers. Alternatively, facilities can be placed on shallow foundations that are designed to tolerate permanent ground displacements. These ground displacements depend on various factors such as the density and thickness of the liquefiable layer, the depth to the liquefiable layer, and characteristics of the ground motion (e.g., intensity, magnitude, and duration). The magnitude of settlement that needs to be incorporated in design must be based on either a deterministically developed design earthquake scenario or a probabilistically developed annual probability of exceedance (or return period).
This paper describes how hazard curves can be calculated to estimate liquefaction-induced settlement under shallow foundations overlying liquefiable soils. These hazard curves were developed using the PEER performance-based earthquake engineering (PBEE) framework (Deierlein et al., 2003). The PBEE framework incorporates the probability of seismically induced ground motions developed from a probabilistic seismic hazard analysis (PSHA), the probability of liquefaction conditioned to the occurrence of a ground motion, and the probability of settlement conditioned to the occurrence of liquefaction. The results of the analyses are discussed, and recommendations are made for incorporation in evaluation of geohazard and designs considering their occurrence.
Application of System-Theoretic Process Analysis to the Isolation of Subsea Wells: Opportunities and Challenges of Applying STPA to Subsea Operations
Authors: Kim H. , Lundteigen M. A. , Hafver A. , Pedersen F. B. , Skofteland G. 
Published: April 2018

Abstract
Systems-Theoretic Process Analysis (STPA) is a recently developed hazard identification technique that is based on control and systems theory. Previous studies on STPA emphasize two major strengths of the method: (1) STPA provides a systematic top-down approach that enables early identification of system flaws, and (2) STPA covers a wider scope of hazards compared to traditional methods. Despite these advantages, there are only a limited number of studies that have applied the method to subsea systems. It is therefore of interest to investigate how STPA can be used to formulate new or verify existing requirements to safety-critical systems for subsea facilities. One example is the isolation of subsea wells initiated by the platform emergency shutdown (ESD) system. The purpose of this paper is to apply STPA to this function, and to discuss opportunities, challenges and possible implications of the results obtained from the analysis.
The paper starts with a thorough literature study and includes an analysis of the insights and recommendations made from other industry sectors and application areas. This review is followed by the STPA analysis of the proposed system, with focus on the identification of the unsafe control actions and safety constraints for subsea well isolation. It is investigated how STPA is able to address specific design philosophies and subsea operating conditions, like fail-safe function of subsea ESD valves, long distance between top-side control system and subsea valves, and dynamic behavior of the control structure. The paper concludes with discussions and suggestions on how the STPA procedure may be improved for application to subsea systems.
A Low-Viscosity Retarded Acid System for Stimulation of High-Temperature Deep Wells
Authors: Sayed Mohammed , Cairns Amy J. , Aldakkan Bashayer S. , Gomaa Ahmed M. , Alnoaimi Khalid R. 
Published: April 2018

Abstract
To enhance the efficiency of acid stimulation treatments in high-temperature carbonate reservoirs, the industry requires a superior retarded acid system that inherently displays high thermal stability, controlled reaction rate, and acceptable corrosion losses. One of the earliest means of acid retardation was through the addition of polymer gelling agents; however, these sytems commonly lead to formation damage. Alternatively, a commonly used approach to slow down the acid/rock reaction rate is through the use of acid-in-oil emulsions (i.e., emulsified acids). The viscous nature of these fluids, however, leads to unfavorably high friction pressures during the pumping process. Additionally, the thermal stability of emulsified acids is questionable at temperatures exceeding 300°F. Herein, we introduce a novel engineered acid system for stimulation of high-temperature carbonate reservoirs. The proposed technology reduces the free water in the system and consequently prevents full dissociation of the acid. Reducing the free water in the acid system was successfully achieved by engineering the acid formulation in the presence of another organic compound that is readily soluble in the acid.
A series of benchtop carbonate dissolution experiments were performed under static conditions at room temperature to identify the optimal engineered formulation needed to achieve the desired retardation effect. The retardation behavior of this system was further supported by reaction rate studies, coreflood measurements and corrosion loss data. The proposed acid system was evaluated at temperatures and pore pressures up to 350°F and 3000 psi, respectively.
Experimental results confirmed that the engineered acid system requires only 0.28 PV to achieve a breakthrough (12 inch core), which represents a significant reduction as compared to some reported emulsified acid systems. Importantly, the fluid formulation was systematically fine-tuned in order to impart the desired fluid-property characteristics: low-viscosity (est. 4 cp), high dissolving power (4.16 lb acid/gal), fast wormhole propagation rate, low corrosion loss (&lt;0.05 lb/ft2, 275°F) and high thermal stability (&gt;300°F). The acid system can be readily mixed on-the-fly with existing equipment. This is a desirable feature particularly when it comes to offshore operations as no special preparation methods are required.
It is the opinion of the authors that this novel acid system provides the industry with a suitable fluid alternative that may offer the potential to enhance oil and gas production in carbonate reservoirs. The fluid is stable at high temperatures and may have the potential to be used in a broad range of stimulation applications. Importantly, this low-viscosity retarded acid system presents the industry with a novel acid alternative where acid retardation by polymer addition or emulsification in diesel is no longer required.