bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiscale Characterization of Foamed Cement Using X-Ray Microcomputed Tomography
Authors: Pang Xueyu , Maxson Joe K. , Jimenez Walmy Cuello , Singh John P. , Morgan Ronnie G. 
Published: August 2016

Abstract
Foamed-cement systems are widely used in deepwater cementing operations because of their various favorable attributes compared to conventional cement systems. For instance, in the Gulf of Mexico, foamed cement is one of the most commonly used systems for shallow hazard mitigation. However, because current standard laboratory equipment cannot accurately simulate the foam-cementing process in the field, knowledge of the actual properties of foamed cement produced in field operations is limited.
In this study, the microstructure of foamed cement produced using field equipment in yard tests is examined in detail. Set foamed cement samples were analyzed using X-ray micro-computed tomography (micro-CT) at different length scales with voxel resolution ranging from 2 to 20 µm. This study establishes the fundamental criteria and procedures necessary to obtain accurate gas bubble size distribution of foamed cement samples using micro-CT technology. The test results suggest that foamed cement should be analyzed at multiple length scales to obtain a better characterization of the gas bubbles in the sample. While a larger region of analysis is useful to obtain a statistically meaningful size distribution of the larger bubbles, small core samples (less than 0.5 in. diameter) and fine scan resolutions (5 µm or smaller) are typically required to obtain an accurate measure of the small gas bubbles in foamed cement.
By comparing foamed cement produced using field equipment with that produced using the traditional multiblade laboratory blender (i.e., the standard API method), this study identifies the key characteristic differences of foamed cement based on different methods of generation. Analysis of the CT-scan images reveal that gas bubbles in foamed cement generated by field equipment have a wide size-distribution range, from less than 20 µm to more than 1000 µm, and the bubble size distribution appears to show little dependence on foam quality. Conversely, the gas bubble size distribution of foamed cement generated by the API method shows a completely different behavior, with both its distribution range and median varying significantly with foam quality. This research serves as a first step toward predicting the influence of gas bubble size distribution on the stability and various other properties of foamed cement to better understand the foam-cementing process in the field.
Challenging Offshore Dynamic Kill Operations Made Possible With the Relief Well Injection Spool
Authors: Oskarsen Ray T. , Rygg Ole B. , Cargol Mike , Morry Brett 
Published: August 2016

Abstract
Before a well is drilled in deep to ultradeep waters or environmentally sensitive areas, operators’ internal rules and regulatory agencies usually call for a contingency relief-well plan that includes dynamic-kill evaluation. Simulations for a worst-credible-blowout scenario often show that the pumping requirements exceed the capability of a relief-well rig, particularly when in deeper waters and/or where the reservoir is shallow. Installing a Relief Well Injection Spool (RWIS) between the wellhead and the blowout preventer (BOP) on a relief well provides additional inlets for pumping kill mud into the well at the seabed and ensures sufficient flow capacity to perform a high-rate dynamic kill. During the pumping operation, one or more additional high-pressure pumping vessels from remote locations are connected to the RWIS inlets using flex lines.
The RWIS system has been validated by hydraulic modeling using the OLGA-WELL-KILL simulator. Two hypothetical case studies, for shallow and deepwater wells, are presented here to show applications of the RWIS and the potential benefits. In both cases, a kill rate of 200 bpm is required at the relief well intersect to stop the uncontrolled flow from a blowout well. For both case studies, the benefit of the RWIS is pronounced and could prevent the need for two relief wells. Relief wells designed to control a deepwater blowout will require long choke and kill (C&K) lines, which could result in significant frictional loss during a dynamic kill with high pump rate. This flow restriction is mitigated by introducing additional inlets at the wellhead.
The Use of Propellants to Stimulate and Enhance Productivity from Tight, Damaged and Low-Quality Reservoirs
Authors: Gilliat J.. , Satti R. P. 
Published: August 2016

Abstract
Propellants have been used in the oil and gas industry for a wide variety of applications including well cleanup, damaged zone treatment, and stimulation. In particular, propellants have a unique place in the industry as a stimulation / enhancement tool that can significantly improve productivity and lower operator costs. However, the success of a propellant-stimulation job depends not just on the operational design/deployment, but also the pre-job evaluation using predictive modelling tools.
This paper focuses on providing insight into the processes involved in propellant-based stimulation, successful case histories (propellants used as standalone tools and combined with the perforating process), and the modeling tools that are used to design and optimize propellant jobs. Case histories showing the benefits of using these tools to lower workover costs and restore productivity for injection and production will be presented. When used as a pre-frac perforating tool, propellants can reduce horsepower requirements by up to 35% in some cases.
Along with the propellant tools, a dynamic perforation modeling tool successfully models the event beforehand to mitigate risk and predict the viability of the process. The software simulates the dynamic response of a cased or uncased wellbore, its contents and the porous rock formation, to the energy released by gas-generating and stored pressure sources. In particular, the modeling tool can be applied to predict fracture propagation, near-wellbore cleanup and skin reduction during wireline and TCP operations.
The results from the case histories and the insight provided by the dynamic modeling software illustrate that, when properly applied, propellant tools can add tremendous value to completion operations by lowering costs and enhancing production. This paper also provides the framework for a completion engineer to better understand the design and optimization of a propellant-stimulation job.
Underbalance and Cleanup Optimization of Perforated Completions Using a Novel Fast Computational Model
Authors: Bale D. S. , Satti R. P. 
Published: August 2016

Abstract
Large-diameter, long-interval tubing conveyed perforation (TCP) operations are an important part of modern deepwater completion design. Safe and cost-effective designs require an understanding of the interdependence between a large set of static and dynamic parameters that characterize the downhole processes affecting a complex well completion. Typically, it is impractical to measure such parameters in a downhole environment. For this reason, physics-based modeling and numerical simulation of transient processes such as static/dynamic underbalance, perforation cleanup, and shock loading are a critical component of the design process.
A significant challenge is that these downhole processes are typically modeled with a dynamically coupled system that includes the reservoir, wellbore, perforation tunnel, tool string and fractures, leading to long simulation times. This is not desirable due to the fact that a single design must satisfy constraints over a large design parameter space, and therefore requires many simulations. This paper introduces a fast computational tool based on dominant flow physics of the perforating process. The new model is benchmarked and verified against current industry-standard dynamic simulators, as well as computational fluid dynamic (CFD) packages.
The novelty of this approach is based on physics at the right scale, resulting in a computational efficiency improvement and simulation times at least an order of magnitude less than other industry-standard simulators. Results for numerical examples representing downhole perforating scenarios provide unique insight into underbalance (i.e., using pressure transients), and subsequent cleanup mechanisms.
In this study, a new fast computational model of the perforation process has been developed based on dominant physics. The benefits of this novel approach include design parameters that are closely tied to the flow physics, and simulation results that are easily interpreted for enhanced perforating job design. Ultimately, these benefits enable the completion engineer to make more informed and faster decisions during the design of a perforating job.
Reaming and Drilling Practice Optimization using Modeling and Simulation Techniques
Authors: Herbig Christian , Linke Christian , Reckmann Hanno , Hohl Andreas , Heinisch Dennis , Boyd Andrew , Vial Michael , Taylor Richard , Kenworthy Andrew , Murphy Suzanne 
Published: August 2016

Abstract
Longer wells and increasing complexity of the bottom-hole assembly (BHA) are causing drilling operations to become harder to achieve. Combined with strict timelines and the demand for higher rates of penetration (ROP), the entire drilling system operates at its physical (loads, bending moment, etc.) and operational (drilled formation, drilling parameters, well path, etc…) limits. Exceeding these limits can induce excessive drilling vibrations and dysfunctions like whirl that can be harmful for bit, bottomhole assembly, reaming device or drillpipe. Neglecting operational limits can therefore lead to damage, wear and tool failures that ultimately result in nonproductive time (NPT) and higher cost.
Additionally, the number of reaming operations increases. The added challenge of complex reaming operations demands supplementary planning effort. In this paper, the authors focus on prejob and post-well analysis using simulation and modeling techniques. The result of the analysis leads to optimized reaming and drilling practices that are further elaborated following close interaction with field personnel. Applying the improved drilling practices result in best-in-class performance and lower nonproductive time.
In-house dynamics simulation software is used to calculate the natural frequencies and corresponding mode shapes of the BHA. Differences in BHA setup are associated, critical excitation sources identified and forced response analysis results compared.
Data from various deployments of a high-end rotary steerable system (RSS) BHA with a reaming device are analyzed and used to validate the simulation results. The data is derived exclusively from a massive salt section (similar formation being drilled) to lessen the formation’s influence on drillstring dynamics.
Incorporation of sophisticated simulation tools plus the close cooperation of field personnel resulted in excellent operational and drilling performance. In today’s challenging drilling applications, the insights gained have highlighted further opportunities for delivering optimal performance, and further assuring bit, BHA, reaming device and drillstring integrity.
Mathematical Modeling of Gas in Riser
Authors: Aarsnes Ulf Jakob , Hauge Espen , Godhavn John-Morten 
Published: August 2016

Abstract
A mathematical model which describes the dynamics of gas being circulated out of a riser is presented. The model is valid for conventional drilling where no backpressure is applied, controlled mud level (equivalent to dual gradient drilling), managed pressure drilling with backpressure, and with a riser gas handler. The presented model is validated with data from a field trial where gas was circulated down the drillstring and into an open riser with a reduced riser liquid level (controlled mud level). Underlying assumptions makes the models conservative. The model is suited to evaluate the procedures for use of a riser gas handler, and an example with automatic control of the rig choke shows how a gas kick can be safely circulated from the riser.
A Semi-Analytical Solution for Estimating the Fracture Width in Wellbore Strengthening Applications
Authors: Zhang Jincai , Alberty Mark , Blangy J. P. 
Published: August 2016

Abstract
Lost circulation is a major challenge in well construction operations, especially where drilling margins are narrow or in pressure-depleted reservoirs. Wellbore strengthening techniques (e.g., StressCage) have successfully been used to increase formation fracture resistance and reduce mud losses during drilling operations. The increase of fracture resistance in sands has been used to improve wellbore stability (through the use of higher mud weights), reduce casing requirements, and access resources that may have been undrillable using conventional drilling methods.
The StressCage technique requires the estimation of the width of an induced fracture at a target fracture length for a given wellbore pressure. This estimation involves either a finite element calculation or a closed form line crack analytical solution. Populating and running the finite element solution requires specialized software and expertise, which has limited its use to larger operators and service companies that are staffed with geomechanics experts. The closed form line crack analytical solution is both simple to implement and easy to use, but it assumes transverse isotropic in-situ stress conditions relative to the borehole axis, which is almost never the case in the presence of a deviated well. This assumption results in either the underestimation of the calculation of the fracture width in the presence of deviation or abnormal in-situ stresses, which can result in a failed implementation of a StressCage formulation.
We have developed a new semi-analytical line crack solution that accounts for stress anisotropy from either borehole inclination or abnormal in-situ stresses. This new solution is simple to implement. The calculation of the fracture width has been verified against finite element calculations through a range of stress anisotropies, borehole sizes, Young’s moduli, Poisson’s ratios, and target increases in wellbore strength.
Multilateral Technology With Intelligent Completions: Challenges and Solutions for Deepwater Subsea Well Operators
Authors: Glaser Mark , Saldanha Savio 
Published: August 2016

Abstract
Multilateral and intelligent well construction and completion technologies has proven themselves to be effective means of increasing recovery rates and improving operational efficiencies in subsea wells, yet, there are no known applications where both technologies have been applied in deep water in the same well. This paper discusses the evolution of the use of both of these technologies in subsea well environments and then the challenges and technology gaps that have to be overcome to develop a fit for purpose solution for deep water wells.
This paper discusses the origins and benefits that the two technologies have brought to subsea wells while presenting examples of the integrations of both in installations in various areas of the world. The unique environment and challenges posed by deep water subsea wells introduce risks such as, limited number of wellhead penetrations, longer stroke lengths to position components in the wellbore, lack of rotational ability due to the control lines and safety concerns. This paper also discusses the successful track record of each technology, developing customized solutions for deep water subsea wells and mitigating risks involved. Finally, the challenges posed by the integration of both technologies in these deep water wells are presented.
In these challenging economic times, the desires for solutions that reduce capital expenditures/operating expenditures (CAPEX / OPEX) are at the forefront of completion design discussion. Integrating various technologies to that effect is the next logical step. Efficient drainage of complex reservoirs can be achieved by effectively combining multilateral and intelligent completions technologies while actively managing CAPEX / OPEX. Monitoring and active control inside the lateral would be the ultimate solution for maximizing reservoir drainage and performance. For that to happen, it would require technology advancement that is currently non-existent or in its infancy stage at best. However the first logical step would be to monitor and control laterals from the mainbore which is achievable with some enhancements to existing technology. The second step would be to incorporate monitoring in the laterals as inductive coupler and disconnect technology begin to prove themselves. Finally as wireless technology, downhole power generation, and battery technology start to evolve, we will be able to monitor and actively control the reservoir within the laterals.
This paper conveys some of the numerous challenges that exist for an integrated completions approach. It will require both operators and service companies to work together to overcome the numerous obstacles; and it requires thinking outside the box and challenging the traditional approach without which we as an industry will be limited in what we can achieve, which in the end is maximizing our return on investment.
A Perforating Tool Kit as a Computational Paradigm
Authors: Wight Jim , Craddock G. G. , Haggerty Dennis , Rojas Fabian , Montiverdi Jonathan , Yadav Arvind , Magdaniel Manuel , Rios Federico , Harive Kevin 
Published: August 2016

Abstract
This paper discusses using a perforating toolkit as a computational paradigm to provide perforating solutions to field personnel. This toolkit provides an extensive list of charges and gun systems and generates the effects on the target rock and overburden pressure. Outputs include depth of penetration and casing hole sizes. It has an improved graphical user interface (GUI) and updated algorithms based on data from the flow laboratory.
The perforating toolkit uses up-to-date API data as the basis for the calculations; simulations are based on parameters set by the user and outputs are in a graphical format, showing the perforating performance within the reservoir. The perforating toolkit software is designed to use improved data obtained from recent laboratory testing. The most up-to-date flow laboratory testing was used to generate the algorithms for the perforating toolkit, generating more precise algorithms and producing improved perforation predictions. Testing involved a broader range of data than was previously used, allowing the software to make more accurate predictions. This new tool was benchmarked using laboratory testing, which demonstrated the quality of the paradigm and its functional use for improved downhole perforating. The software provides the field user with a tool to predict downhole shaped-charge performance quickly and in a cost-effective manner. The models also allow a number of parameters to be varied for a better comparison of different scenarios.
This paper discusses how new data across a broader range from the flow laboratory was used to improve the basic software algorithms and help provide the most accurate prediction of downhole charge performance.
Fluidic Diode Autonomous ICD Single-Phase Testing
Authors: Corona Georgina , Greci Stephen , Least Brandon , Yin Weiqi , Plumlee Jacqueline 
Published: August 2016

Abstract
This paper discusses a new generation of inflow control devices (ICDs), which are known as autonomous inflow control devices (AICDs) that can balance production flow and restrict the unwanted fluid. This paper describes the functional testing conducted to evaluate the performance of the fluidic diode type AICD for oil conditions of less than or equal to 1.5 cP and the restriction of unwanted gas in field-like conditions. It will also compare flow performance curves to those of a traditional nozzle-type ICD.
Unbalanced inflow from a reservoir can result in water or gas breakthrough, and unless this situation can be addressed satisfactorily, valuable reserves may be lost. When oil is producing from all zones, the AICD will behave as a passive ICD, thereby balancing flow. However, when lower-viscosity fluids break through, the AICD provides a choking effect, significantly reducing flow from the zone responsible for producing these undesirable fluids. Such autonomous characteristics enable a higher recovery rate of oil and also reduce the cost for processing the unwanted fluids. The AICD creates this change in production performance without control lines, moving parts, or electronics.
The AICD presented in this paper, also known as Range 1, has an innovative fluidic sensor that is highly sensitive to the fluid properties and is currently best suited for oil viscosities of 0.3–1.5 cP. The Range 1 AICD uses an autonomous on/off type switching function upon gas breakthrough to control gas inflow instead of a gradual change in total flow performance as provided by other inflow control device types. Oil flow is fed directly to the exit port of the AICD, while gas is "switched" to a highly restrictive, spinning path that limits gas production through the tool. Results from single-phase experimental flow testing with oil and nitrogen are presented and discussed. The test results demonstrate that the AICD is an effective tool for restricting gas production.
The discussion further shows that if technology, such as the new AICD, is applied to a well-completion design, total oil recovery can be enhanced by increasing the life of the well and reducing the production of undesirable fluids.
Metal-to-Metal Sealing and Anchoring Expandable Hanger in Gulf of Mexico: Development, Collaboration, and Execution
Authors: Dagle Odee , Johnson James , Moeller Daniel 
Published: August 2016

Abstract
Reliably deploying liner hangers in offshore applications is critical to successful wellbore construction. This case study reviews the pre-job planning, collaboration, and deployment of the first metal-to-metal sealing and anchoring expandable liner hanger (ELH) in the Gulf of Mexico. A set of particularly problematic deepwater wells will be discussed. The intensive collaboration between the service company and operator, as well as the job-specific design considerations of the metal-to-metal hanger and service tool, will be included.
The operator and service company collaborated to quantify and implement agreed-upon design concepts. Additional collaboration was required during the job preparation for a challenging well with multiple sidetracks from previous unsuccessful alternate-technology liner-hanger deployments. Collaborative design considerations for the hanger include features to handle extreme tensile loads through the service tool prior to hanger installation and through the liner hanger post installation. Job-preparation collaboration included planning a fit-for-purpose job, with an in-depth look at the parent casing, hanger, wellbore geometry, and other critical aspects of the job. Additional discussion will center on the benefits of metal-to-metal sealing technology at the liner top in conjunction with elastomeric-contingency sealing technology.
This paper disseminates technical information to increase operator awareness of a new technology and its application. The collaboration between the service company and operator describes a needed trend in the industry to successfully construct wells in a challenging environment. Developing well-specific, fit-for-purpose equipment enables a decrease in time-vs.-depth rates owing to increased running and operational speeds and a reduction in remediation activities as a result of increased reliability. The metal-to-metal and redundant elastomeric sealing and anchoring ELH technologies assist with both increased efficiency for current operations and the ability to push the industry's technological envelope.