bluuebunny/crossref_metadata_2025_split huggingface dataset:
Data-Driven Analytics for Production Impact Assessment during Unplanned Facility System Events
Authors: Popa Andrei S. , Leon Hugo , Medel Juan , Nquyen Tuan , Cassidy Steve , Tubbs Dallas 
Published: April 2015

Abstract
A data-driven approach to successfully analyze and evaluate the production fluid impact during facility system “divert” events is presented. The workflow effectively identifies opportunities for prompt event mitigation and system optimization. The methodology used included data streaming, advance computations (i.e., low pass filtering, co-variance, moving averages, standard deviation) on high frequency data (i.e., 5 seconds), visualization, data mining, and rules extraction. Additionally pattern recognition and analytics were employed for detection and computation of event duration, maximum and average pressure during event, respectively corresponding maximum, and average impacted production. Custom tools were developed to allow visualization and computation of the massive amounts of data available (44 streams @ 5 seconds measurement frequency) for the selected events over the past few years. The model was applied to the newest events and found to significantly outperform previous manual approaches, not only by driving intelligent business decisions as opposed to quick short term reactions, but also by curtailing production loss and returning the system to normal operation conditions.
The study identifies areas of improvement and opportunities to mitigate production impact during “divert” events. Main recommendations include procedures to: reduce event duration, maintain pressure at a level where production is not impacted, monitor casing pressure at well level across the field, and alternatives to divert the back pressure in the mature areas of the field.
The paper demonstrates that applied data driven analytics led to learnings and observations that drove business impact in management of facility systems during “divert” events. Due to its practical simplicity and efficiency, the technology and workflows are now considered for use in surveillance and monitoring of other facility systems in the San Joaquin Valley fields and beyond.
Modeling Fugitive Gas Annular Migration Conditions in Unconventional Wells Under Lifetime Stresses
Authors: Wilson Douglas , Eustes A. W. , Fleckenstein W. W. 
Published: April 2015

Abstract
The newest shale extraction technologies are being rapidly deployed in North America and enthusiastically considered internationally. These innovative methods employ marked changes from conventional development mechanisms, notably in wellbore completion and reservoir stimulation. Though early results provide a powerful argument for the continued development of these resources, long-term outcomes may introduce more uncertainty, especially considering the as-yet unobservable lifetime risks to wellbore integrity. The viability of downhole production mechanics and assurance of the environment are strong functions of geomechanic stresses, which themselves are dynamic during stimulation and production. Knowledge of the downhole mechanics of these new development strategies suffers from the absence of long-term field observations.
Finite element analysis (FE analysis) provides a powerful and oft-employed approach to model long-term effects of dynamic forces on mechanical systems. The ANSYS model presented analyzes stresses on horizontally drilled, massively stimulated well completions, with a goal of modeling structural behavior of the downhole mechanics and its effects on potential unwanted migration of reservoir fluids.
The static structural geometries of the wellbore (casing, cement, and near-wellbore rock) are modeled at specific, critical times during the life of the well, (e.g., after stimulation, after MIT). The results suggest some general design parameters to help mitigate the risk of downhole fluid segregation failures, The analysis guides the development of a fluid migration model, being developed at CU-Boulder, designed to evaluate annular migration risk of modern, onshore wells.
A highly deviated well presents a wellbore stress environment that differs from its vertical analog. Pressured casing in anisotropic stress environments allows increased shear and tension on the cement-casing bond during construction and completion. In addition, the cement-casing cohesive bond is a significant factor in the prevention of a microannulus during normal well construction and completion.
The absence of any interfacial cohesion increases the risk of a microannulus in both a differentially stressed and differentially constrained cement sheath. Our goal is to contribute to the understanding of completion integrity at critical times during the life of the well, and to guide development of industry best management practices.
Hole-Cleaning Optimization: A Case History from Three High-angle Wells in Austria
Authors: Thompson John , Wilkes John , Marland Chris , Martin Antony , Bindl Benedikt , Brunneder Michael 
Published: April 2015

Abstract
Hole cleaning is a critical part of ensuring successful execution, as wells become more challenging to drill and well designs more complex.
The philosophy of model, measure, and optimize was applied to the task. Three consecutive, similar, and co-located high-angle (85–95°) 8-½-in. sections were drilled, which provides an objective comparison of the efficacy of effective and consistent drilling practices, teamwork, and engineering.
The operator's challenge was to: Mitigate the risk of stuck pipe during drilling and tripping,Reduce the need for backreaming to reduce potential for excess wellbore and down-hole tool damage, andDeliver efficiency savings.
The primary aim to execute these deliverables meant ensuring effective hole cleaning while drilling and prior to tripping to facilitate a clean, uneventful trip out of hole.
During the planning phase, the hydraulics system and the torque and drag were initially modelled to give a baseline measurement to assess the drilling operations and were continually updated to ensure accuracy. Additionally, modelling highlighted a major contributor to previous hole-cleaning issues from the drilling fluid.
During the execution phase, drilling and tripping practices already in place drew particular scrutiny, which lead to a discussion between the operator and service provider. Proactive operator leadership led to collaboration with the service provider to review the practices and procedures. This collaboration resulted in presentations for rigsite personnel to emphasize the importance of standardized procedures and to lead to subsequent improvement in each well.
This case study investigates each section's performance and the positive results from procedural improvements, mud-property optimization, and cost savings of proper hole cleaning, which resulted in the following:No stuck-pipe/lost-tool incidents,Ability to pull on elevators at the final TD of the third well,63% improvement in tripping-out time at TD (comparing Well 3 to Well 1, 15 hours compared to 40-½ hours), and15% improvement in liner-tripping time.
Interactive Web Based 3D Wellbore Viewer Enables Collaborative Analysis
Authors: Phillips Walter 
Published: April 2015

Abstract
Common wellbore visualizations are depicted using 2D perspective views. This approach is limited and potentially misleading. Of particular interest to rod-pumping and progressing cavity pumps is the amount of side loading placed on the rod string throughout the wellbore. By illustrating the trajectory of a wellbore in 2D, some nuanced geometries can be easily lost. The familiar “corkscrew” wellbore, for example, is very difficult to depict through simple perspective views. A corkscrew is best visualized at a specific camera angle where the shape is apparent. This best viewing angle is generally not at 90 degrees, where typical 2D perspective views are generated.
Distributed wellbore visualization tools can be applied to both design and analysis of pump installations. Interactive views help to identify points in the well where problems may occur, or have occurred. Strategic placement of downhole equipment such as pump depth relative to perforations and historic fluid levels can be done in a more intuitive way, taking into account a more accurate understanding of the wells geometry.
The use of standards based modern web technologies enables rapid deployment of such a tool to both desktop and mobile devices. Three dimensional graphics acceleration was previously only available in the web browser through plugins and other 3rd party software installations. 3D graphics can now be rendered natively in most modern web browsers without the need for any additional software.
Imaging-Aided Study of Relative Permeability Response to Temperature in Diatomaceous Rocks
Authors: Vega Bolivia , Kovscek Anthony R. 
Published: April 2015

Abstract
Relative permeability, and its temperature dependence, is one of the most important and often adjusted physical relationships during history-matching of thermal oil recovery projects. To increase understanding of oil-water relative permeability behavior as a function of temperature, we conducted and interpreted laboratory-scale experiments. In these studies, high-temperature, spontaneous and forced isothermal water imbibition tests were conducted on diatomaceous reservoir core samples of clayey and sandy types. Tests were carried out at temperatures of 45 and 230 °C (113 °F and 446 °F). Tests included spontaneous counter-current water imbibition followed by forced co-current water imbibition to residual oil saturation. Wettability shift was assessed experimentally through the Amott index. Dependence of endpoint phase saturation and relative permeability on temperature was also apparent. The wettability response observed indicates wettability transition to greater water-wetness with increasing temperature. X-ray computed tomography imaging provided the 3D distribution of porosity and aided us in following the spatial distribution of water saturation as a function of time in the samples throughout the imbibition process. Water saturation evolution varied among samples. Front-like water advance and more or less uniform imbibition were measured. Heterogeneity at the core scale was evident in both porosity and water saturation images. A commercial simulator was used to model and to history match core-scale flow behavior. Relative permeability curves were created consistent with the experimentally found oil and water relative permeability endpoints. Importantly, a heterogeneous wettability distribution was incorporated in one case to match experimental observations. Study results include relative permeability curves and wettability indices as a function of temperature.
Practical Application of Data-Driven Modeling Approach during Waterflooding Operations in Heterogeneous Reservoirs
Authors: Amirian Ehsan , Chen Zhangxin 
Published: April 2015

Abstract
Quantitative assessment of different operating areas and uncertainty appraisal due to reservoir heterogeneities are crucial elements in optimization of production and development strategies in oil sands operations. Evaluation of waterflooding performance that involves detailed simulations is usually deterministic, cumbersome, expensive (manpower and time consuming), and not quite suitable for practical decision making and forecasting, particularly when dealing with a high-dimensional data space consisting of a large number of operational and geological parameters. Data-driven modeling techniques, which integrate a comprehensive data analysis and machine learning methods, provide an attractive alternative especially for extremely nonlinear system forecast.
In this paper, an exploratory data analysis is applied to construct a comprehensive training data set from waterflooding field data, which entails various attributes describing characteristics associated with reservoir heterogeneities and other relevant operating parameters. Artificial neural network (ANN) is employed as a data-driven modeling alternative to predict waterflooding production in heterogeneous reservoirs, an important application that is lacking in the existing literature. ANN utilizes a training data set to identify all significant patterns and relationships that exist between the input and output attributes. The data-driven model is subsequently tested using a verification data set involving cases that have not been used at the training stage.
This paper highlights the great potential of data-driven modeling techniques for practical applications and to be used as a viable tool for analyzing a large amount of competitor data efficiently. In addition, the proposed approach can be integrated directly into most existing reservoir management routines. Given that robust forecasting and optimization of heavy oil recovery processes is a major challenge faced by the industry, the proposed research also has great potential to be applied in other recovery projects such as steam assisted gravity drainage (SAGD) and solvent-additive steam injection.
An Experimental Investigation of Viscous Oil Recovery Efficiency as a Function of Voidage Replacement Ratio
Authors: Kim Tae Wook , Vittoratos E. , Kovscek A. R. 
Published: April 2015

Abstract
Recovery processes with a voidage replacement ratio (VRR=injected volume/produced volume) of 1 rely solely upon viscous forces to displace oil whereas a VRR of 0 relies upon solution-gas drive. Activating a solution gas drive mechanism in combination with waterflooding using periods of VRR less than 1 (VRR &lt;1) may be optimal for recovery. Laboratory evidence suggests that recovery for VRR &lt;1 is enhanced by emulsion flow and foamy oil at pressures under bubble point for some crude oils. This paper investigates the effect of VRR for two crude oils referred to as A1 (88 cP and 6.2 wt% asphaltene) and A2 (600 cP and 2.5 wt% asphaltene) in a sandpack system (18 ʺ long and 2 ʺ dia.). The crude oils are characterized using viscosity, asphaltene fraction, and acid/base numbers. A high-pressure experimental sandpack system (1 Darcy and Swi=0) was used to conduct experiments with VRR's of 1.0, 0.7, and 0 for both oils. During waterflood experiments, we controlled and monitored the rate of fluid injection and production to obtain well-characterized VRR. Based on the production ratio of fluids, the gas-oil and-water relative permeabilities were estimated under two-phase flow conditions. For a VRR of 0, the gas relative permeability of both oils exhibited extremely low values (10-6 ~ 10-4) due to internal gas drive. Water floods with VRR &lt; 1 displayed encouraging recovery results. In particular, the final oil recovery with VRR=0.7 (66.2 % OOIP) is more than 15% greater than that with VRR=1 (55.6 % OOIP) using A1 crude oil. Results for A2 with VRR=0.7 (60.5 % OOIP) were identical to the sum of oil recovery for solution gas drive (19.1 % OOIP) plus waterflooding (40.1 % OOIP). An in-line viewing cell permitted inspection of produced fluid morphology. For A1 and VRR = 0.7, produced oil was emulsified and dispersed as gas bubbles, as expected for a foamy oil. For A2 and VRR &lt;1, foamy oil was not clearly observed in the viewing cell. In all cases, the water cut of VRR=1 is clearly greater than that of VRR=0.7. Finally, three-phase relative permeability was explored based upon the experimentally determined two-phase oil-water and liquid-gas relative permeability curves. Using well known algorithms for three-phase relative permeability, however, did not result in good history matches to the experimental data. Numerical simulations matched the experimental recovery versus production time acceptably after modification of the measured krg and krow. The degree of agreement with experimental data is sensitive to the details of gas (gas-oil system) and oil (oil-water system) mobility.
Technology Qualification and Installation Plan of Efficient and Accurate Multilaterals Drilling Stimulation Technology for Sandstone Oil Application
Authors: Rice Kevin , Jørgensen Thomas , Solhaug Kristian 
Published: April 2015

Abstract
Most reservoirs cannot produce efficiently without stimulation. Multilateral wells are known to increase productivity but can be time consuming and challenging to implement. Stimulation methods such as hydraulic fracturing can be complex to deploy and difficult to direct. Multilateral stimulation technology (MST) used to stimulate carbonate reservoirs with efficiency and accuracy has been well documented through the concept, development and field trial stages (Freyer et al 2009, Freyer et al 2011, Rice et al 2014, Carvajal et al 2015). This paper will discuss the evolution of a new multilateral stimulation technology which has been developed and qualified as part of a Joint Industry Project (JIP) with Fishbones, Statoil, ENI, Lundin and Innovation Norway. The technology increases oil recovery rates from tight formations by means of an efficient pumping process which creates accurately placed laterals into the formation. Previous MST systems utilize jetting action along with the chemical reaction between hydrochloric acid (HCl) and carbonate formations to create the laterals. This paper will discuss the further progression of this technology to qualify a new method known as multilateral drilling stimulation technology (MDST), which can be applied in non-reactive formations and in those that are otherwise inefficient to jet. The MDST utilizes the existing fluid system in the wellbore and standard rig pumping equipment to create a significant number of pathways into the reservoir. The qualification testing to the current status of Technology Readiness Level 4 (TRL4), Qualified for First Use, will be discussed along with the reservoir simulation and installation planning for downhole deployment.
Fast Production Optimization with Decline Curve Analysis Under Facility Constraints: A Field Case Study
Authors: Kritsadativud P. , Jafarpour B. , Ekkawong P. 
Published: April 2015

Abstract
Production optimization can play a major role in increasing recovery and decreasing operation cost. In many oilfields, the geology, production operations, and their related constraints are very complex. These complexities can complicate the formulation and solution of the pertinent optimization problems and increase the computational cost of finding a solution. Although full reservoir simulation provides detailed analysis and prediction of reservoir performance, the significant uncertainty and complexity of reservoir models can make the simulation results and their interpretations questionable. Moreover, in some cases, a reservoir model may not even be available to perform full simulation for performance optimization. The cost and complexity of developing full-scale simulation models, together with the considerable computational overhead associated with production optimization (especially under geologic uncertainty), call for development of fast proxy models for production optimization. To this end, various reduced-order and surrogate models have been designed to approximate the production behavior of a reservoir at a fraction of the computation required for full simulation.
We present an efficient production optimization scheme by integrating constrained optimization with fast decline curve analysis for predicting well production performance. The proposed production optimization approach is formulated as a constrained optimization problem by defining a desired objective function and a set of existing field/facility constraints. An efficient gradient-based optimization algorithm is then adopted to solve the resulting optimization problem for a single timestep. The optimization is then coupled with the decline curve analysis to predict future production rates. The optimization process is performed recursively in time for a specified duration. The predictions with the decline curve analysis are reasonable so long as the operating conditions remain unchanged. Using field data, we demonstrate that the proposed formulation can provide fast solutions to large-scale production optimization problems. The results in this paper suggest that the developed technique can be applied to improve production performance and operation efficiency with a minimal computational cost when compared to production optimization with full-scale reservoir simulation. It also offers the flexibility to adjust the problem formulation under various field conditions and is particularly useful when a full-scale reservoir model does not exist simulate the reservoir response for production optimization.
Fracking or Hydraulic Fracturing: How Media Shapes Public Perception and Regulatory Process
Authors: Schwartz Megan , Tormey Daniel R. , Middaugh Molly 
Published: April 2015

Abstract
Bans or moratoria on hydraulic fracturing are in place or being considered worldwide. In large part, these actions stem from relatively data-free media presentations of risks associated with hydraulic fractions. Our objective is to analyze the influence of media and public perceptions in shaping policy related to hydraulic fracturing and to use this evaluation to provide insight on balancing science with public perception in judging political risks and guiding public policy. By balancing science with public perception, good policy and a social license to operate result.
We conducted a literature review of the role of media in influencing public opinion on political issues and then focused the conclusions found in the literature onto the topic of hydraulic fracturing. We evaluated the influence of media, including movies, television, and traditional new outlets, as well as internet sources such as blogs, news aggregators, non-governmental organization (NGO) campaigns, and social media, and then compared these sources to the influence of published scientific literature in shaping public perception and political and regulatory oversight of hydraulic fracturing. The results of our analysis show that the large disconnect between scientific data and public opinion makes it difficult for elected officials and regulatory agencies to develop well-founded policies that regulate hydraulic fracturing in a manner that is accepted by both the public and industry. Based on these results, our study illustrates that public officials need to balance public opinion with data-rich scientific studies and analysis, and then weigh political risk when crafting legislation and public policy.