bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wireline Operations - All-Inclusive Risk Management
Authors: Castillo H. C. , Haigood A. G. 
Published: March 2018

Abstract
Many of the high-impact operational and safety incidents in wireline operations are the direct result of incorrect selection or inappropriate operation of surface equipment. Examples of such incidents are pulling tensions on the rig-up equipment components above their safe working loads and using winch units incapable of pulling the tensions required to retrieve heavy tool strings in deep or tortuous wells.
Current processes and simulation software used to plan wireline operations are focused on the risks and conditions in which the downhole tools and wireline cables selected will operate; they do not include specific assessments of the adequacy of the surface equipment selected and their associated operating practices.
In this paper, we show the outcome of implementing a set of surface equipment assessments in a popular wireline forces modeling software suite. The surface equipment covered in this initial implementation include the wireline cable, hoist (winch) unit, wireline drum, chains/slings, sheave wheels, load cells, powered capstans, and rig anchoring points. We also demonstrate the merits of the quantification of the selected hoist unit horse power and torque versus the tension and speed profiles simulated at all depths for the free and stuck tool conditions.
The use of processes and forces modeling software, including suitability assessments of the surface equipment and operational choices, is particularly relevant to long and/or tortuous wells. Selection of marginal surface equipment in these types of wells can impose severe operational limitations not identified during the job planning phase and create hazardous conditions that can result in safety incidents and large financial losses.
The Fatigue Behavior of Concentric Coiled Tubing
Authors: Luebke Garrett , Tipton Steven M. 
Published: March 2018

Abstract
This paper investigates the fatigue behavior of Concentric Coiled Tubing (CCT) and specifically the influence of internal and annular pressures on fatigue life and diametral growth rate. This behavior is assessed relative to that of conventional Coiled Tubing (CT) using samples of identical material, with software modelling predictions providing an additional basis for comparison. Samples of 1.25" CT were situated concentrically within samples of 2.375" CT, and both were repeatedly bent and straightened on a standard CT fatigue testing system, with separate pressures in the inner volume and the annular volume between the CT samples. Current SPE literature does not include prior art for any type of concentric coiled tubing fatigue testing or analysis. The testing apparatus used in this study is the industry standard for the assessment of conventional coiled tubing, however this paper presents the world-first experimental study of concentric coiled tubing fatigue.
Since the testing focused on the failure of the smaller diameter samples, baseline fatigue tests were only conducted on the smaller, inner coiled tubing samples. These results are cross referenced to current fatigue models. Concentric samples were tested on the same machine and setup parameters, using special fixturing that allowed the internal sample to move axially on one end, with its pressure contained. A matrix of pressure differentials was examined, with various levels of inner and annular pressures. The exterior pressure was atmospheric for all tests. The orientation of the longitudinal Electric Resistance Welding (ERW) seams in both samples was examined in this study.
The current approach to monitor CCT fatigue integrity is to use a conventional CT fatigue model, based on the differential pressures caused by the inner CT pressure, annular CCT pressure, and well pressure. While pressure may be monitored accurately, uncertainties exist with regards to the influence of radial stress in the tube wall and factors such as mechanical abrasion between the inner and outer coiled tubing strings, especially due to the presence of internal longitudinal ERW seams. Current models assume perfect concentricity; however, eccentricity varies throughout the string in real-world applications. Results from this study include an empirical derating factor, post mortem failure analysis (including assessment of the influence of ERW seam abrasion), diametral growth analysis, and recommendations for future testing.
Depleted Well Intervention in Extended Laterals Using Coiled Tubing and Commingled Fluid Systems
Authors: Williams Troy A. 
Published: March 2018

Abstract
The objective of this paper is to clearly outline the basic principles and techniques required to successfully perform well intervention in wells with low-pressure formations, thief zones, and/or depleted reservoirs—specifically, horizontal or highly deviated wells. The paper aims to review the considerations and provide an example of reliable execution in its most basic form, including simplified calculations designed to be used in conjunction with advanced modeling software available in the industry. Coiled-tubing intervention in lateral wells with fluid-loss potential is inherently high risk. The risk of poor solid suspension or loss of fluid circulation results from the inability to avoid fluid loss and causes costly job failures, lost workstrings or equipment, or reduced well production. For land-based operations in the United States, coiled tubing has been reliably and successfully deployed in depleted and low-reservoir-pressure wells that were unable to support a hydrocarbon or water column to surface. These jobs include sand cleanouts, re-fracture preparation cleanouts, and underbalance millouts in extended laterals.
Commingled nitrogen and water-based systems were used to reduce hydrostatic pressures exerted on the reservoir and, thereby, allowed for successful continued circulation. The fluid system was adapted to each well intervention to consider formation type, reservoir fluid composition, job requirements, BHA requirements and limitations, chemical compatibility, cutting suspension potential, and foam integrity. When combined with real-time monitoring of, and response to, well conditions, the occurrence of job failure was greatly reduced.
Long Term Storage of Coiled Tubing: Industry Best Practices and Conclusions Based on Evaluation of Stock Strings
Authors: Elliott K. J. , Williams C. D. , Li Y. , Arriaga E. 
Published: March 2018

Abstract
An unprecedented industry downturn has created surplus stock: new coiled tubing strings that have been stored at manufacturing facilities and at coiled tubing bases all over the world. This paper will address best practices for coiled tubing storage as well as recommendations based on the testing program for stock strings that have been destroyed.

Methods, Procedures, Process
An unprecedented industry downturn has led to a surplus of inventory of strings that have been stored for at least one year. This program will evaluate stored inventory by gathering samples at multiple locations of stored strings including bias welds and parent tubing from both ends and the center. Additional samples will be located on the bottom of the wrapping (to verify if residual fluids affect coiled tubing storage). These samples will be tested in low cycle fatigue and evaluated for the presence of corrosion pitting.

Results, Observations, Conclusions
The low cycle fatigue testing program evaluates multiple stored strings, including different grades and outer diameters. The samples are compared against existing commercially available models and can also be visually examined (after the removal of any surface rust) for the presence of corrosion pits. The results of the testing program will allow for the comparison of performance against storage conditions and time. Additionally, it will provide an opportunity to confirm that all workstring grades experience similar storage issues (regardless of grade) as all grades have a similar alloy chemistry (high strength low alloy steel).
The test results will then be evaluated against commercially available modeling software to determine if storage corrosion led to defects, and if so provide some coiled tubing storage best practices that can be applied for coiled tubing manufacturers. These best practices can then be carried over to service companies storing the strings at their yards around the world.

Novel or Additive Information
This testing program is the first-ever destructive evaluation of coiled tubing strings after long-term storage to determine the effects of storage. The paper is expected to set guidelines for long-term storage of coiled tubing.
30 Years of Continuous Coiled Tubing Modeling Software Development and Field Applications Creating New Capabilities
Authors: Aitken W. A. , Livescu S. , Craig S. 
Published: March 2018

Abstract
During the last three decades a coiled tubing (CT) modeling software package has been continuously developed to assist in the planning and executing of global CT operations. The first models were steady-state. In the past decade these models have been extended to consider transient effects of operations as they are executed. These models will also be used in the not-so-distant future to automate CT operations. In this paper, a review of all these models is presented for the first time.
The development of a computer program was initiated in the early 1980s to help understand the downhole flow and pressure conditions during CT operations. Utilizing multi-phase rheological and frictional correlations obtained from laboratory flow loop testing, the CT flow model was extensively validated against global field data. Later, CT force and stress analysis models, considering such effects as the specific well geometry, mechanical friction, CT size, shape and material strength, were developed to predict lateral reach and assist in preventing downhole CT failures. While the most common and simplest approach within the industry is still to use steady-state models, in practice, the downhole conditions during CT operations, such as well cleaning, well unloading, well control, stimulation, cementing, underbalanced drilling with nitrified fluid, etc., are transient. Consequently, the steady-state models have been extended to account for downhole transient effects at the pre-planning and execution stages of CT operations. In addition, with the advent of the state-of-the-art CT telemetry systems, it is possible to acquire the downhole data in real time and use the transient CT software model to automate and optimize CT operations, increasing their safety and efficiency.
A review is presented for the first time about the steady-state and transient models included in the CT software model, with details about each model and how they performed during 30 years of operations. Results and discussions regarding the extensive validation of the software against laboratory and field data are also presented. Several field cases from around the world help illustrate the transient nature of CT operations and the benefits of using the transient simulation in the pre-planning and execution stages of these operations.
The paper presents the results from 30 years of global experience with the CT modeling software program. The mathematical models, validation against laboratory and field data, verification against other models available in literature, and case histories are described. The current trends within the industry are leading to a shortage of experienced CT field engineers, so the use of CT software models to increase the efficiency, compliance and safety of CT operations has never been as important as now.
Redefining Battery Operation for High-Power Downhole Tools
Authors: Segura J. , Erkol Z. 
Published: March 2018

Abstract
The use of conventional downhole batteries, which are intended for low voltage/current, faces hurdles when it comes to operating tools designed for surface power provided through a cable. The high power consumed by some of these tools requires careful characterization of parameters such as current, transients, and battery capacity at different loads and temperatures.
The battery power tool developed for high-power tools uses three battery packs, here used in series, to boost input voltage, with a provision to use three additional packs in parallel for additional current. Battery characterization efforts at currents higher than 1 A were performed at different temperatures (75°C, 100°C, and 150°C) to explore the behavior of lithium battery chemistry, with a total of 48 battery packs tested. The electronics design to boost battery voltage up to 200 V to support a pulsed neutron tool is also presented.
The result of this engineering effort is a system that can provide more than 20 Ah of power and enables more than 10 hours of continuous operation of pulsed neutron tools. It also allows more than 100 hours of operation of conventional production logging tools. A tool planner software is provided for the field users to estimate the battery operation time for a specific job. Those benefits are illustrated by the field deployment results of this solution since 2014, with examples of successful operations in the Kingdom of Saudi Arabia, the Congo, and Gabon.
Innovation in Conveyance with Carbon Composite Rod
Authors: Troup Duncan 
Published: March 2018

Abstract
An intervention program in a well may require the use of both electric line and slick line to convey a variety of services. This calls for the swapping between conveyance systems, often multiple times in a single intervention program. A viable solution is a new system for carrying out interventions in oil wells which is designed to convey electrical, electro-mechanical and mechanical services. The paper aims to describe this new conveyance system and discuss field experience to date.
Carbon composite material technology confers the benefit of higher strength at reduced weight when compared to conventional cable materials and the slick surface eliminates the need for grease injection pressure control systems. The ability to perform both precision logging and heavy duty mechanical services within the same rig-up allows complex well programs to be executed with only one unit and a multi-skilled crew.
The first field trial for the new conveyance system was conducted offshore in the North Sea, and proved the carbon composite rod capable of performing both mechanical intervention (16 runs) and electric line (12 runs) services. The strength of the rod material enables the running of long and heavy bottom hole assemblies. Run in conjunction with electrical or mechanical release devices, the carbon composite rod is able to deploy strings beyond the capability of conventional wirelines.
The physical strength and rigidity of the rod, coupled with its light weight, allow efficient planning of intervention programs where mechanical and electric services are combined in a single rig-up. Since the first trial, advances in technique have brought 10km (32,000 ft.) rods to the field enabling intervention access to, and perhaps more importantly retrieval from, extended reach wells. Equally of interest is the ability of the rod to access short lateral sections without resorting to tractor technology, allowing faster and more economical intervention.
Dendritic Acidizing Update: The Light at the End of the Tunnel
Authors: Wehunt C. Dean , Lattimer Stefan K. , McDuff Darren R. 
Published: March 2018

Abstract
The paper provides an update on recent advances for, and summarizes global experiences with, dendritic acidizing methods, aka acid tunneling. The scope of the paper includes both Coiled-Tubing (CT) deployed and non-CT methods, and discusses process limitations, candidate selection criteria, job design factors, operational learnings, risks, and surveillance requirements and opportunities. The paper contains a comprehensive review of published information for three different tunneling methods and relevant information for several other tunneling methods. The literature information is supplemented by, depth, temperature, and pressure records for the three processes which are discussed in detail. Execution factors such as logistics required, length of time required, and volumes of acid and other fluids used are also compared for three methods.
Previous papers have focused on only one of the methods, whereas the authors will discuss acid job optimization, process risks, and surveillance requirements for multiple acid tunneling methods in substantially greater depth than have past authors. The three methods detailed in the paper are all viable but may have different niches. Differences in the job counts for the different methods are easily explained by differences in process vintages, execution speeds, and depth limitations. Previous optimization efforts were focused on tunnel creation but not acid job effectiveness in terms of the wormholes generated adjacent to the tunnels; however, some progress is now being made in that regard. There are differences in the processes regarding pushing or pulling the jetting nozzles into the tunnels, and differences in resulting tunnel trajectories. Pre-job caliper data are more critical for one of the processes than for the others, and there are significant differences in ability to measure or control tunnel direction. The tunneling tools have different sizes, but when tool size alternatives are available, the larger tool sizes offer no clear advantages to the operator. Useful risk mitigation measures are also discussed in the paper. The paper includes a comprehensive bibliography to facilitate further examinations of the technology alternatives by other petroleum industry professionals.
Back to Life by a Coiled Tubing Gas Lift Pilot Project in Colombian Foothill Wells
Authors: Almeyda Oscar , Castañeda Claudio , Higuera Josue , Torres Monica , Portela Fernando 
Published: March 2018

Abstract
A Coiled Tubing Gas Lift (CTGL) pilot project was implemented in a reservoir with a compositional fluid system in the Casanare foothills area in the northeast of Colombia. This paper presents the life cycle of the project from design to operation including production test results after installation to "revive" wells with high water production and very low gas liquid ratio.
High pressure gas was injected through conventional 1-3/4" and 2" 110 Kpsi coiled tubing, installed inside completion strings and hung to the Christmas tree to reduce cost of the project and avoiding recompletion of the well in a low-cost environment. A pilot project included three well was executed ending 2015, being a world first CTGL for 1-3/4" and 2" CT deployment beyond 12,000 feet.
Challenges for deployment of CT string, well control aspects, barriers for control upon disabling of DHSV and master hydraulic valve among of moderate CO2 corrosion impact were some of the risks associated to this project. A pilot installation on three wells was successful and this paper compiles lessons learnt from this process including candidate selection, deployment, material selection, well intervention and risk assessment among of operational performance and pipe recovery after end of project life.
Unlocking the Potential of Your Coiled Tubing Post Job Data
Authors: Murphy Chris , Sams Andrew 
Published: March 2018

Abstract
"Run in hole", "stop CT", "pickup", "drop pumps"… All common commands heard in the control cab during a coiled tubing plug drillout (CTDO). What drives the decision making process and what information has been processed to arrive at such a conclusion? During a coiled tubing (CT) operation, many parameters are being acquired including pump rate, pressures, weights and speeds, and the success of the operation relies on how the supervisory personnel interpret this data and advise on next steps. At the end of the job, if lucky, this crucial data is archived in the catacombs of the well file on some network server. What if instead, this information was analyzed to detail the operation, develop performance metrics to help understand why the results were what they were, and ultimately provide guidance for future operations? This paper discusses an algorithm developed to support analysis and a philosophy of job review that has been utilized to robustly process a rich, continuous and widely available CTDO data set.
Successful Creation of Permanent Reservoir Isolation Barriers Using Coiled Tubing on the Norwegian Continental Shelf NCS
Authors: Thomson Iain 
Published: March 2018

Abstract
As well production declines in mature fields and becomes unprofitable, operators must shut the wells in and permanently plug and abandon (P&A) them. It is presently estimated that thousands of such wells will require permanent P&A.
Historically, the P&A of wells in the North Sea were performed using either drilling or workover rigs. In many cases, wells drilled from fixed platforms in the North Sea no longer have operational drilling rigs requiring recommissioning of existing facilities or mobilization of workover rigs.
Regulatory authorities in the North Sea have defined standards for creating permanent reservoir barriers for the P&A of wells, which includes requiring a "rock-to-rock" barrier.
This paper discusses an alternative approach to P&A using coiled tubing (CT) processes and techniques to create these permanent reservoir barriers. One process rigged CT up from the drill floor and pipe deck in a conventional fashion. During the intervention, standard milling and tubular cleanout techniques were used to gain access to the reservoir, and then a novel perforating, washing, and cementing (PWC) technique created the reservoir barrier. Finally, an additional tubing punch run was made, and the barrier was tested. In a single, multiwell campaign, 13 wells in the field had successful permanent reservoir barriers created using CT.
This paper illustrates the successful creation of permanent reservoir barriers using CT. Additionally, the paper highlights that using CT can provide economic benefits for creating the barrier compared to more conventional drilling or workover rigs.
Faecal sludge reuse in Birendranagar, Nepal: a case study of the world health organisation's multiple barrier approach
Authors: Abeysuriya Kumi , Khawaja Nadira , Mills Freya , Carrard Naomi , Kome Antoinette , Willetts Juliet 
Published: March 2018

Abstract
This case study presents an innovative initiative to facilitate safe reuse of faecal sludge (FS) by introducing the World Health Organisation's multi-barrier approach within a Farmer Field Schools framework for participatory experiential learning. A novel FS treatment process based on fermentation by ‘effective organisms’ (EM) was piloted to test the feasibility, safety and acceptability of the resulting fertilizer. Fermented FS in agricultural application was found to perform at least as well as other common fertilizers it was compared with, while its lower cost delivered higher profits per cultivated hectare. Participating farmers found it easy to prepare and use, and viewed it favourably overall. EM-based fermentation was, however, found to be insufficient as an FS treatment to render safe reuse, particularly with respect to helminth inactivation. The paper discusses strengthening the treatment barrier, and improving the application of the multi-barrier approach by the systematic consideration of non-treatment barriers using guidance from the WHO's Sanitation Safety Planning Manual. Further research to enable effective monitoring and support systems for maintaining treatment and non-treatment barriers, and for understanding long term impacts of fermented FS application is recommended. In combination, adequately treated fermented FS may be a candidate for scale up necessary for meeting the Sustainable Development Goals.