bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field Scale Simulation Study, Investigating the Effect of Geological and Operational Parameters on Solvent Co-Injection Process in Athabasca Bitumen Reservoir
Authors: Souraki Y. , Ashrafi M. , Jahanbani Ghahfarokhi A. , Torsaeter O. 
Published: April 2015

Abstract
Considerable proportions of the hydrocarbon resources in the world are in the shape of heavy oil and bitumen. In an environment of low economic returns for heavy oil operations, Steam Assisted Gravity Drainage (SAGD) process appears very promising from a technical point of view. However, it has two significant deficiencies, namely high energy and water requirements and environmental issues of green house gas (GHG) emissions. Recently, hybrid processes have attracted attentions, since they benefit from advantages of steam and solvents together. The vaporized solvents dissolve into the viscous oil and help the steam to reduce bitumen viscosity dramatically. Moreover, hybrid processes alleviate the high consumption of water and energy while improving the GHG emissions.
The goal of this paper is to evaluate and compare the efficiency of SAGD and solvent co-injection (SCI) using experimental PVT properties of the Athabasca bitumen and a thermal numerical reservoir simulator. Steam trap control was applied in this study to hamper the steam production. Sensitivity analysis was performed to find out the effects of various geological parameters such as reservoir thickness, horizontal and vertical permeability, horizontal and vertical shale barriers and reservoir pressure, as well as operational parameters like injector location, solvent diffusivity, different solvent types and different concentrations of injected solvent. Three different crude oils from Cold Lake, Athabasca and Lloydminster reservoirs were selected to investigate the effect of viscosity.
Results divulged great recovery of bitumen and reasonable amount of steam-oil ratio (SOR) for both processes. Applying solvent co-injection with steam reduced the amount of steam required and consequently decreased SOR, while higher recovery factors (R.F.) were obtained. Butane, pentane, hexane, heptane and dodecane were tested solvents in this study. Among them, hexane was used to investigate the effect of solvent concentration. Using higher concentration of injected solvent resulted in higher R.F. and lower SOR, however, economy of the process regarding the use of highly valuable solvents should also be considered.
Higher vertical, horizontal permeability and reservoir pressure had positive effect on oil production. In addition, thicker reservoir showed better and more economical results in terms of oil production and SOR. Presence of shale barrier has a negative effect on oil production. This negative effect is more pronounced in case of horizontal than vertical shale layers. Applying solvent diffusivity coefficients revealed that very fine grid system in three directions is needed to evaluate the effect of diffusion precisely.
Autoencoder-derived Features as Inputs to Classification Algorithms for Predicting Well Failures
Authors: Liu Jeremy , Jaiswal Ayush , Yao Ke-Thia , Raghavendra Cauligi S. 
Published: April 2015

Abstract
This paper presents the results of using autoencoder-derived features, rather than hand-crafted features, for predicting rod pump well failures using Support Vector Machines (SVMs). Features derived from dynamometer card shapes are used as inputs to the SVM algorithm. Hand-crafted features can lose important information whereas autoencoder-derived abstract features are designed to minimize information loss. Autoencoders are a type of neural network with layers organized in an hourglass shape of contraction and subsequent expansion; such a network eventually learns how to compactly represent a data set as a set of new abstract features with minimal information loss. When applied to card shape data, we demonstrate that these automatically derived abstract features capture high-level card shape characteristics that are orthogonal to the hand-crafted features. In addition, we provide experimental results showing improved well failure prediction accuracy by replacing the hand-crafted features with more informative abstract features.
Impact of Remaining Water in Hydraulic Fractures on Well Productivity — Field Examples from Saudi Arabian Sandstone Reservoirs
Authors: Rahim Zillur , Al-Anazi Hamoud , Al-Kanaan Adnan , Pacheco Eduardo 
Published: April 2015

Abstract
The full potential of a well cannot be ascertained if the proppant is not cleaned up properly after a fracture treatment, particularly in tight gas formations. This paper makes an in-depth evaluation of the impact of fracturing water that remains trapped and unproduced within the proppant pack. This water must be differentiated from the condensed water or water from the reservoir that may be produced. The paper studies some of the main fracturing and reservoir characteristics and identifies variables that have a major impact in reducing the proppant pack conductivity and well production. The major variables studied and analyzed are the fracture fluid and broken gel viscosity, the proppant material, closure stress, fracture conductivity, reservoir pressure, and formation permeability. The paper presents an approach to evaluate and correlate different fracture and reservoir variables to the post-fracture sustained production rate. The study was conducted in two steps; first is a sensitivity study using a full scale numerical simulator and using important reservoir properties from a particular gas field in Saudi Arabia along with the characteristics of typical fluids and proppants pumped during a multistage fracturing treatment in horizontal wells in a low permeability sandstone reservoir. The second step consisted of analyzing the actual post-frac water recovery, test gas rate, and long-term production performance. Comparisons are drawn to establish the variables that impact well productivity the most.
The paper presents important plots to illustrate the flow back behavior and well productivity under different fracturing fluids scenarios. There have been practical steps taken to minimize fracture damage, thereby maximizing well deliverability. The factor impairing deliverability the most is the unbroken gel viscosity. The early time production behavior is a function of broken gel and fracture conductivity. With the improved treatment scheduling, use of better fluids and proppants, and application of novel completion methods, the well performances have been significantly improved in challenging, heterogeneous, and low permeability reservoirs.
Energy Security in the Los Angeles Basin: A New Look at an Old Treasure
Authors: Paul D.L. , Asaithambi R. , Ershaghi I. , Crompton J. , Gautier D. 
Published: April 2015

Abstract
As the home of oilfields with the highest production per acre of any oil Basin in the world, California's daily oil demand continues to exceed its daily production. This energy security issue requires smart thinking to enhance onshore production, while protecting the sensitive California environment. Motivated by U.S. Geological Surveys (USGS) study on the potential of LA Basin, we analyzed four abandoned fields as analogs to obtain more refined estimate of proven undeveloped (PUD).
A Los Angeles Basin study was conducted on selected major fields and some abandoned fields by examining the existing data sources. We conducted an uncertainty analysis of each parameter and developed a basin wide cross-correlation approach where sparse data from analog formations could fill the gap and provide the critical information needed for the estimated recoveries. Based solely on publicly available data, we were able to develop a preliminary estimate of PUD remaining reserves for each field.
The study provided several key observations. First, there is a need for handling diverse data sources to evaluate the re-development potential of a given field using advances in data integration and data mining. Second, there is a need for integrating formats ranging from old handwritten to digitized documents. Third, the use of performance data from analog geologic formation is required in estimating potential undeveloped reserves.
We believe the combination of diverse data sets (including data such as completion histories on individual wells, subsurface geology from old and new logs and core data from various sources and warehouses, production histories and work-over data) and modern informatics technology can lead to identification of redevelopment opportunities in LA Basin. The USC Energy Institute, with the support of the petroleum industry, is intent on examining these possibilities.
Semantic Web Technologies for External Corrosion Detection in Smart Oil Fields
Authors: Saeed M. , Chelmis C. , Prasanna V. , Thigpen B. , House R. , Blouin J. 
Published: April 2015

Abstract
The Oil & Gas industry always seeks to prevent loss of containment (LOC). To prevent such incidents, engineers rely on inputs from various asset databases and software tools to make important safety-related assessments and decisions on a daily basis. One cause of LOC in offshore platforms is external corrosion. The state of corroding assets is extensively monitored and recorded through a variety of data collection mechanisms by various processes and people. Due to heterogeneity of these data sources, providing on-demand access to information with an integrated view can be challenging. A unified view of current data sources is desirable for decision making as it could lead to identification of telltale signatures of LOC events. However, manually cross-referencing and analyzing such data sources is labor intensive. Another challenge is knowledge management, which refers to a systematic way to capture the results of various engineering analyses and automated prediction models. It is beneficial to capture this knowledge for two reasons: (i) auditing, archiving, and training purposes, and (ii) mining of LOC signatures and warning signs for developing machine learning prediction techniques.
We propose the application of semantic web technologies for a holistic and expressive representation of various heterogeneous data sources at scale to deal with information management issues. The key elements of our approach are a reusable asset integrity monitoring ontology and an external corrosion ontology that model various elements from the domain, and a knowledgebase that can serve as a system of record for observed data as well as new knowledge acquired through inferencing and machine learning analytics. We further describe the methodology followed to populate the knowledgebase and how it can be used to convey assessments and alerts to the right people so that actions are taken to address identified risks.
We show that data from multiple sources can be integrated into a central repository serving as a single endpoint for maintaining and retrieving knowledge. We present our integration framework and evaluate the advantages of our approach in terms of expressiveness and ease of information access.
Our metadata and knowledge management platform for external corrosion can be highly beneficial for our strategic vision of LOC early prediction and prevention. The expressiveness afforded by the semantic web stack enables rapid integration and facilitates analysis of multiple data sources related to corrosion detection. The end goal for an enterprise is not just storing and managing lots of data, but to get actionable insights fast. Our proposed solution is a stepping stone towards LOC prevention.
Frac Sleeve Designed for Multi-Zone Cemented Laterals
Authors: Chauffe Steve , Pence Nigel , Harris Michael 
Published: April 2015

Abstract
A ball-activated sliding sleeve design for multistage cemented lateral completions has been developed that allows multiple frac sleeves to be opened using the same diameter ball, significantly increasing the total number of sleeves available in the completion design. This paper discusses the sleeve design, the challenges associated with cemented laterals, the results of initial field installations, and the ramifications for completion design and execution.
Ball-activated sleeves were introduced to overcome limitations of plug and perf designs and facilitate longer and more complex completions. As these completions have evolved, the technology has reached inherent design limitations. This is especially true in cemented lateral completions. These installations require a series of incrementally smaller balls and ball seats that reduce wellbore ID and ultimately limit the total number of sleeves that can be used in the completion.
To further extend lateral length and accommodate the cemented laterals, a sliding sleeve device has been developed that allows multiple sliding sleeve valves to be opened with the same size ball and seat. The sliding sleeve design allows up to 90 individual sleeves to be opened as a single point of entry completion without dropping a ball diameter smaller than 4.00-in. in 5.500-in. casing, or a 3.25-in. ball in 4.500-in. casing. This increases wellbore ID over the length of the completion, and increases the total number of sleeves or sleeve clusters that can be employed in the completion design. The higher number of available sleeves affects the completion design, whether it uses single sleeve per stage or clusters of sleeves. In addition, lateral length of the completion is not constrained by the number of sleeves or the reach of coiled tubing.
Cemented installations in the US Marcellus, Utica Shale, and Spraberry plays have enabled single-point-of-entry stimulations that optimize hydraulic fracturing pressure and provide a focused frac. In some applications, this has reduced pump rates and surface horsepower requirements by as much as 50% and also reduced the overall frac time. Experience also indicates these completions reduce water requirements by minimizing over-flushing of the formation. These cemented installations illustrate the potential of continued changes in completion designs and the viability of longer laterals.
This paper is the first published examination of field performance in the initial installations of the sliding sleeve technology. Field results and data from sleeves installed in Marcellus, Utica Shale, and Spraberry completions are presented. Based on performance in these applications, the paper reviews completion design considerations facilitated by the ability to install larger numbers of sliding sleeves over longer cemented laterals.
Boundary Conditions: A Key Factor in Tubular-String Buckling
Authors: Huang Wenjun , Gao Deli , Wei Shaolei , Chen Pengju 
Published: April 2015

Summary
Boundary conditions for tubular-string buckling are divided into two kinds on the basis of the virtual work of the nonaxial force on the boundary conditions of the tubular string—namely, the first and the second kinds of boundary conditions. The first kind of boundary conditions means that the virtual work of no-axial force is zero, and both the conventional pinned and fixed ends belong to this kind. The second kind of boundary conditions means that the virtual work of no-axial force is not zero. Previous studies on tubular-string buckling mainly focus on the first kind but ignore the second kind of boundary conditions. In this paper, the effects of the two kinds of boundary conditions on tubular-string buckling are analyzed.
The deflection of a long tubular string constrained in a wellbore is divided into the full helical-buckling section and transition section, whereas the transition section is divided further into the no-contact section and perturbed-helix section. The qualitative corresponding relation between boundary conditions and tubular-string buckling in transition and full helical-buckling sections is clarified. To clarify the quantitative relation between boundary conditions and tubular-string buckling, a general-packer model is proposed to depict the two categories of boundary conditions. With the general-packer model, the general potential energy of the tubular string is deduced. According to the minimum-potential-energy principle, the existence and stability of full helical-buckling solutions are given. The deflections of the tubular string in the no-contact and perturbed-helix sections are deduced with buckling differential equation and beam-column model. The bending moment, shear force, and contact force on the tubular string caused by buckling are also analyzed. The results show that boundary conditions, especially the second kind of boundary conditions, are an important factor that makes the tubular-string buckling problem complex, and this paper provides one source for a deeper understanding of boundary conditions.
Short Radius Horizontal Drilling System Optimization in Yates Field Unit Provides Excellent Directional Control and Highly Economic Completions
Authors: Tank W. J. 
Published: April 2015

Abstract
Yates Field Unit in Pecos County, Texas, has recently drilled its 100th short radius horizontal drainhole. The program has been a technical as well as economic success for the field, providing efficient completions in this highly fractured reservoir.
In the early stages of the program (1986 – 1990), short radius drilling in Yates Field Unit was performed using strictly rotary drilling systems. In 1992, Odorisio and Curtis1 reported on the introduction of articulated downhole mud motors to the program and the impact of the initial modifications to the system. Since that time over 75 additional drainholes have been drilled. Two other drilling systems have been tested and many improvements have been made to the original system. This paper documents the optimization that has occurred in the drilling systems and results obtained from this work.
A Two Layered Control Architecture for Prosthetic Grasping
Authors: Kakoty Nayan M. , Hazarika Shyamanta M. 
Published: April 2015

AbstractThis paper presents a two layered control architecture - Superior hand control (SHC) followed by Local hand control (LHC) for an extreme upper limb prosthesis. The control architecture is for executing grasping operations involved in 70% of daily living activities. Forearm electromyogram actuated SHC is for recognition of user’s intended grasp. LHC control the fingers to be actuated for the recognized grasp. The finger actuation is controlled through a proportionalintegral- derivative controller customized with fingertip force sensor. LHC controls joint angles and velocities of the fingers in the prosthetic hand. Fingers in the prosthetic hand emulate the dynamic constraints of human hand fingers. The joint angle trajectories and velocity profiles of the prosthetic hand finger are in close approximation to those of the human finger
Towards Measuring Quality of Interaction in Mobile Robotic Telepresence using Sociometric Badges
Authors: Kristoffersson Annica , Coradeschi Silvia , Eklundh Kerstin Severinson , Loutfi Amy 
Published: April 2015

AbstractThe field of mobile robotic telepresence for social communication is in rapid expansion and it is of interest to understand what promotes good interaction. In this paper, we present the results of an experiment where novice users working in health care were given a guided tour while maneuvering a mobile robotic telepresence system for the first time. In a previous study, it was found that subjective presence questionnaires and observations of spatial configurations based on Kendon’s F-formations were useful to evaluate quality of interaction in mobile robotic telepresence. In an effort to find more automated methods to assess the quality of interaction, the study in this paper used the same measures, with the addition of objective sociometric measures. Experimental results show that the quantitative analysis of the sociometric data correlates with a number of parameters gathered via qualitative analysis, e.g. different dimensions of presence and observed problems in maneuvering the robot.
Cooking Behavior with Handling General Cooking Tools based on a System Integration for a Life-sized Humanoid Robot
Authors: Watanabe Yoshiaki , Nagahama Kotaro , Yamazaki Kimitoshi , Okada Kei , Inaba Masayuki 
Published: April 2015

AbstractThis paper describes a system integration for a life-sized robot working at a kitchen. On cooking tasks, there should be various tools and foods, and cooking table may have reflective surface with blots and scratch. Recognition functions should be robust to noises derived from them. As other problems, cooking behaviors impose motion sequences by using whole body of the robot. For instance, while cutting a vegetable, the robot has to hold one hand against the vegetable even if another hand with a knife should be moved for the cutting. This motion requires to consider full articulation of the robot simultaneously. That is, we have difficulties against both recognition and motion generation. In this paper we propose recognition functions that are to detect kitchen tools such as containers and cutting boards. These functions are improved to overcome the influence of reflective surface, and combination shape model with task knowledge is also proposed. On the other hand, we pointed out the importance of the use of torso joints while dual arm manipulation. Our approach enables the robot to keep manipulability of both arms and viewing field of a head. Based on these products, we also introduce an integrated system incorporating recognition modules and motion generation modules. The effectiveness of the system was proven through some cooking applications.
A Distributed Algorithm for Cooperative 3D Exploration under Communication Constraints
Authors: Rathnam Ravi Kulan , Birk Andreas 
Published: April 2015

AbstractAn algorithm for distributed exploration in 3D is presented which always keeps the robots within communication range of each other. The method is based on a greedy optimization strategy that uses a heuristic utility function. This makes it computationally very efficient but it can also lead to local minimums; but related deadlocks can be easily detected during the exploration process and there is an efficient strategy to recover from them. The exploration algorithm is integrated into a complete control infrastructure for Autonomous Underwater Vehicles (AUV) containing sensors, mapping, navigation, and control of actuators. The algorithm is tested in a high fidelity simulator which takes into account the dynamics of the robot, and simulates the required sensors. The effect of the communication range and the number of robots on the algorithm is investigated.
Multiattribute Utility Copulas for Multi-objective Coverage Control
Authors: Valicka Christopher G. , Rekoske Richard A. , Stipanovic Dušan M. , Abbas Ali E. 
Published: April 2015

AbstractThis paper presents theoretical and experimental results related to the control and coordination of multirobot systems interested in dynamically covering a compact domain while remaining proximal, so as to promote robust inter-robot communications, and while remaining collision free with respect to each other and static obstacles. A design for a novel, gradient-based controller using nonnegative definite objective functions and an overapproximation to the maximum function is presented. By using a multiattribute utility copula to scalarize the multiobjective control problem, a control law is presented that allows for flexible tuning of the tradeofs between objectives. This procedure mitigates the controller’s dependence on objective function parameters and allows for the straightforward integration of a novel global coverage objective. Simulation and experiments demonstrate the controller’s efectiveness in promoting scenarios with collision free trajectories, robust communications, and satisfactory coverage of the entire coverage domain concurrently for a group of differential drive robots.