bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crown Plug Pulling Performed as Riserless Light Well Intervention in the Gulf of Mexico – Overcoming the Challenges
Authors: Andrews Garry , Luviano Angel 
Published: March 2015

Abstract

Objectives/Scope
Having a reliable backup plan is vital to ensure successful riserless light well intervention (RLWI) operations. This paper will present learnings from a subsea operation where the contingency solution was engaged to resolve a critical issue. The need for thorough back-up planning will be discussed along with the planning process, execution and lessons learned.

Methods, Procedures, Process
Crown plugs are conventionally retrieved using slickline jarring; however, high performance shifting tools on electric line are gaining foothold due to their ability to apply a focused, axial force downhole. Up to 33,000 lbs of force can be exerted through the use of a bi-directional, hydraulic ram. These electric line (e-line) stroking tools can be fitted with various shifting or pulling tools for lightweight mechanical services. For subsea interventions this is good news as space is particularly limited on vessels, which means that intervention solutions that simplify logistics by reducing equipment and crew is sought after.

Results, Observations, Conclusions
The case to be presented is from a RLWI operation in the Gulf of Mexico where a crown plug had failed to release. Slickline (SL) was the first method to be put into action. On the first attempt 148 jars failed to retrieve the plug, then another 199 jars yielded the same result. It was believed that these repetitive attempts had broken the seal, resulting in saltwater inflow that had created hydrates. 25% Methanol Ethanol Glycol was pumped while jarring, but eventually the contingency plan was activated. This consisted of a hydraulic stroking tool, which successfully managed to remove the upper crown plug and thus allowed the operation to continue without further downtime.
The operator would have had six months of deferred production (being unable to open the sleeve to the upper zone) if the crown plug was not retrieved as they would have needed to wait for a riser. This underlines the importance of having an adequate contingency solution to overcome the challenges in riserless interventions. The benefits will be increased operational efficiency and reduced overhead costs.

Novel/Additive Information
This was the first operation where a crown plug was pulled during a RLWI operation with an e-line bi-directional stroking tool. The tool in this case was capable of 33,000 lbs of force; however, since the execution of this operation, further developments in engineering have led to a redesigned stroking tool with the ability to apply up to 60,000 lbs of force. What opportunities that opens up for RLWI operations will also be presented.
Utilizing a Wall Thickness Measurement Device to Improve the Accuracy of Coiled Tubing Fatigue Calculations
Authors: Traugott D. A. 
Published: March 2015

Abstract
Coiled tubing (CT) monitoring tools are being utilized on a larger percentage of field jobs now as compared to the past. They are being used on both CT intervention and CT drilling operations. The objective of this paper is to demonstrate how a wall thickness measurement device can enhance and improve the calculations made by a CT fatigue algorithm.
Experimental work was done which shows how the wall thickness can vary depending on the pump rates, the fluid being pumped and the amount of tubing that is spooled on the reel. Reference four provides detailed information related to wall reduction in CT during pumping operations. Typically, fatigue models will utilize an estimated, nominal or minimal wall thickness to perform the fatigue calculations.
The amount of wall reduction in CT can vary greatly and as a CT string acquires fatigue, there is a chance that the estimated wall thickness may not reflect the actual wall thickness of the pipe. Recent modifications to fatigue tracking software allow the user to incorporate the real-time (or recorded) measured wall thickness into the fatigue calculations. This paper will discuss the experimental work, the modifications to the model, and case histories in which the wall thickness measurement device was used.
Calculating the CT fatigue using the measured wall thickness will increase the accuracy of the CT fatigue profile. This will allow CT service companies to operate at an increased efficiency. Operating companies will also benefit from this technology because there will be fewer fatigue failures at the well site due to the increased accuracy in the fatigue calculations.
Coiled Tubing Deployed Multistage Horizontal Fracturing Technology: Lesson Learned and Case History in Egypt
Authors: Kareem E. Abdel , Salah M. , Farran A. El , Conrad B. , Beltagy A. El 
Published: March 2015

Abstract
Economic production from marginal reserves in mature fields has always been a major development challenge. Drilling horizontal wells and deploying coiled tubing (CT) multistage hydraulic fracturing stimulation treatments is now a proven solution for mature field development because it exposes more stimulated production zones.
Khalda and Umbarka fields are two mature fields located in the Egyptian Western Desert. They are characterized by their low, depleted reservoir pressure and laminated shaley sands (Upper Bahariya formation). Their hydrocarbon reserve contents are significant. However, because of their relatively low permeability and thin layers, it is very difficult to produce economically from this formation without using hydraulic fracturing. Single-stage hydraulic fracturing treatments in vertically drilled wells resulted in a production of 25 to 40 B/D per well, which is uneconomic for field developments.
Drilling horizontal wells into the best sand layer of the Upper Bahariya sand and performing seven isolated stages of hydraulic fracturing treatments by deploying CT technologies resulted in impressive production responses (1,800 B/D initial production) from this reservoir, which makes this development economical. Deploying CT to the operations exponentially improved its efficiency; seven isolated fracturing stages were performed along the lateral and more than one million lbm of proppant was pumped during three days through one single CT trip in the well.
This paper provides a comprehensive description of the lessons learned from two case histories where CT fracturing techniques for multistage stimulation were applied to achieve maximum production in the field and improve the efficiency of multistage fracturing operations.
Coiled Tubing Deployed Gas and Water Shutoffs in Alaska Utilizing a Polymer Gel and Microfine Cement
Authors: Robertson D. B. , Brown M. A. , Duong L.H. , Ivanova O.V. , Tambe A. 
Published: March 2015

Abstract
A common problem in oil and gas wells is excess free gas or water production from only certain portions of the completed interval. Other portions of the lower completion may still have viable oil or gas production potential if a method can be devised to successfully shut off the unwanted fluids. A coiled tubing deployed profile modification technique was developed primarily to shut off excess free gas production from the heel of cased and perforated horizontal oil wells. The technique has also been used for water and gas shut-off in both vertical and horizontal wells in a variety of lower completion types. The technique involves installing a temporary plug back to protect the toe or bottom most perforations to be preserved, then pumping a polymer gel followed immediately by a microfine cement to shut off the shallower or heel perforations. The objective of the gel and cement is to intentionally damage the rock matrix for a radius of ~2 ft around the perforated intervals to be shut off, creating a zone of little or no permeability adjacent to the wellbore. If successfully executed, there is no cement to be milled out of the liner post squeeze and no restrictions or liner diameter reduction after the job. Approximately 30 horizontal wells have had a cumulative total of almost 13,000 ft of perforated intervals squeezed with this method. The technique has also been used to shut off liner corrosion leaks in horizontal wells and for perforation shut off in deviated wells. Post-job production logs in several of the wells indicated little or no flow from the squeezed intervals even 1 to 2 years after the job.
Milling Faulty Lubricator Valve Using Innovative E-Line Conveyed Core Bit
Authors: Seng Wong Chun , Maitland Bryan , Singh Jagdish , Elnaeim Mohamed Ibrahim 
Published: March 2015

Abstract
Field A is a gas field located in Malaysia-Thailand Joint Development Area. As the field matures after 10 years of production, the number of idle gas wells has been increasing due to various issues such as low tubing head pressure, mechanical problems and sand fill. Currently, the operator has embarked on an aggressive, reactivation campaign to restore production through interventions.
Well A became idle in January 2013 due to unknown reasons and was selected as a pilot well for the re-activation campaign. Tubing Retrievable – Surface Controlled Subsurface Safety Valve (TR-SCSSV) cycling and Critical Device Function Test (CDFT) were performed successfully, but did not impact the production. In August 2013, lubricator valve (LV) diagnostics were performed using a Lead Impression Block (LIB) tool which indicated that the lubricator valve above the TR-SCSSV was only 80% open. As such, this malfunctioning lubricator valve (LV) prevented any future interventions for diagnostics, zonal isolation or the addition of perforations in order to fulfill the objectives of the idle-well reactivation campaign.
An in-depth, internal review had been conducted previously to evaluate all the available solutions in the market from both a technical and economic perspective. To enhance the chances of success, an innovative e-line conveyed core milling bit solution was selected for the pilot job in well A to restore full access to the well.
A customized solution using a 4.55 inch milling core bit run on e-line managed to successfully mill the malfunctioning lubricator valve and restore access to the well with substantial cost savings and lower risk compared to coiled tubing (CT) operation. Both milled coupons were retrieved with the aid of a catcher and brush combination designed into the bit. This managed to restore the access for the future intervention, zonal isolation and additional perforations in this well.
This paper shares a detailed case study of Well A in terms of technology selection, operation execution, lessons learnt, and future recommendations. It is evident that e-line conveyed, core milling bit technology is technically and economically feasible to mill malfunctioned lubricator valve, thus eliminating the need of expensive solutions such as CT or rig intervention.
Recent Developments in Mechanical Descaling Operations: A Case Study from Saudi Arabia
Authors: Al-Buali M.H. , Abulhamayel Nahr , Leal Jairo , Ayub Mohammed , Driweesh Saad , Molero Nestor , Ahmed Danish , Raza Ali , Valley Joseph La , Alfonzo R.I. Ortega , Vejarano E.R. 
Published: March 2015

Abstract
Scale removal in sour gas wells has been one of most challenging operations in Saudi Arabia during the last decade. Operators face particularly demanding downhole environments with temperatures above 300 °F, significant concentrations of H2S and CO2, presence of complex mixed-scale deposits with limited dissolution, and risk of H2S release and corrosion with chemical removal methods. These conditions have led to mechanical removal methods using coiled tubing (CT) as the preferred technique for well descaling operations.
During the last 5 yr, CT descaling operations have consisted of temporary formation isolation via bullhead using CaCO3 chips as a bridging agent, mechanical scale removal with CT milling and high-pressure rotary jetting tools, and abrasive perforation or matrix stimulation to enhance well productivity. Mechanical alternatives for isolation with bridge plugs are not feasible due to the presence of FeS scale in the wellbore. Wellbore configurations also require pump rates above 2.0 bbl/min to ensure suitable cleanout and transportation of solids to surface.
The recent incorporation of CT equipped with a rugged version of fiber optic telemetry and a downhole measurements package into the descaling operations workflow has enabled pumping rates above 2.0 bbl/min. Key bottomhole data has also been obtained, leading to a better understanding of the scale removal progress, optimization of downhole tool operation; reduced well intervention risk, and enhancement of overall job efficiency.
During the CT mechanical descaling stage, differential pressure across a high-pressure rotary jetting tool was kept at its optimum range of operation while maintaining slight overbalance conditions to minimize the risk of gas influx and avoid loss of circulation while removing the formation isolation. Throughout the abrasive perforating stage, real-time depth correlation saved one CT run (i.e., ±24 hr), and higher pump rates significantly reduced operation time and maximized shot size and penetration.
This paper discusses an enhanced workflow for CT descaling operations where the implementation of the real-time downhole measurements package with an enhanced working envelope resulted in a significant increase in operational efficiency, reduced risk, and optimized job performance.
A Novel Fatigue Assessment of CT with Defects Based on Magnetic Flux Leakage
Authors: Liu Zhanke , Zheng Andrew , Diaz Oscar O. , Hauglund Lauren 
Published: March 2015

Abstract
Conventional models have been proven to be successful in predicting the mechanical fatigue life of coiled tubing (CT) without defects. However, defects of various types, including mechanical, manufacturing or corrosion defects, on CT are commonplace in the real world. The impact of such defects on CT fatigue life has been widely recognized. Today's common practice heavily relies on prove-up and manual measurement of defect dimensions, to assess the defect severity on tubing integrity issues, such as fatigue life. Such practice tends to be inefficient, user-dependent, and inconsistent in fatigue and severity assessment; sometimes it's even not feasible in the case of internal defects.
A novel defect severity analysis based on magnetic flux leakage (MFL) was used to quantitatively assess the CT fatigue life reduction due to mechanical defects. This new quantitative approach allows consistent, automated in-line fatigue analysis during operation, as it does not depend on a user's manual measurement of defect dimensions. The new model results compared well with experimental data. The analysis method was successfully used in fatigue assessment of realistic field defects.
Achieving Economically Successful Coiled Tubing Composite Plug Drillouts in Extended Reach Wells
Authors: Ahn J. 
Published: March 2015

Abstract
As horizontal completions are set at increasing depths, an efficient and economical composite plug coiled tubing (CT) drillout (CTDO) process becomes increasingly important. Therefore, it becomes a significant challenge when multiple composite plugs must be drilled out within a single well. By evaluating and making enhancements to each part of the process, thus reducing and possibly eliminating wiper trips, CT can provide an economic solution for these extended reach composite plug drillouts. The net benefits of this include less pipe fatigue, less fluid and chemicals pumped, and an overall more efficient and economic drillout. Extended reach plug drilling operations require particular attention to detail, combining technical, equipment, and operational improvements to reliably reach total depth (TD) in an efficient and safe manner.
This paper discusses the importance of the following six areas suggested for a successful plug drillout process: CT string design related to wellbore tubulars and deviation.Bottomhole assembly (BHA).Flowback arrangement.Drilling techniques.Fluid system.Monitoring and control during the job of the associated drillout parameters.
This paper additionally focuses on two case histories where wiper trips were successfully minimized/eliminated using the discussed method and process enhancements. The first of these is in the Williston basin, where a well (10,135 ft vertical and 9,868 ft lateral) with 24 composite plugs was successfully drilled out using 22,230 ft of 2 3/8-in. CT. In the Denver-Julesburg (DJ) basin, a well (6,780 ft vertical and 7,815 ft lateral) with 39 composite plugs was successfully drilled out using 17,990 ft of 2-in. CT.
The synergy of the six areas followed during the CTDO operations has proven to be a cost effective and reliable process, saving the operator well intervention time. Results and recommendations are presented including the lessons learned from the implementation of the process enhancements within these two case histories.
Optimizing CT Milling Efficiency with the Use of Real-Time CT Modeling Software
Authors: Yeung John , Opel Steve , Smalley Ed 
Published: March 2015

Abstract
In the last decade, the number of horizontal wells drilled in North America has risen dramatically. As a result, there has been an associated increase in the use of the plug and perforation system and the ball-drop system used to complete these horizontal wells. After the fracturing treatment has been completed, the bridge plugs or ball seats are subsequently milled out via the use of coiled tubing (CT).
During the plug or ball-seat milling phase, it is difficult to control weight-on-bit at the end of the CT. If the injector releases too much weight at surface, then the weight-on-bit is too high and the downhole motor can experience a stall. Alternatively, if the injector is not releasing enough weight at surface, then there is insufficient weight-on-bit to mill out the plug or ball-seat. Given that these operations are performed in horizontal wells, it is difficult to predict the optimal weight-on-bit without the presence of real-time downhole measurements.
The current data acquisition software used on CT field operations does not analyze or interpret the data - - it only records the measurements. As a result, it is an arduous process to identify trends in pressure, depth or CT string weight changes over an extended period of time. However, analyzing changes in these variables is critical for optimizing the CT milling operation.
This paper focuses on an innovative technique for analyzing real-time CT job data that can be used to calculate the required surface weight needed to achieve the optimal weight-on-bit. Furthermore, the technique also enables real -time interpretation of CT job data to confirm that the mill is making the desired progress. This technique has been implemented as a utility within a leading CT modeling software package. This paper will also present field case studies that demonstrate how the new CT interpretation utility software has optimized the milling efficiency in horizontal wells.
Cost Effective Solutions to Achieve Injection Post Toe Valve Failure
Authors: Trebing Cody , Whitworth Jeff , Beszterda Alex 
Published: March 2015

Abstract
The use of pressure-activated toe valves in a completion string is yet another innovative approach to completing a horizontal well. This technology eliminates the need for perforating guns prior to a multi-stage hydraulic fracturing (frac) operation. Subsequently, the operator can greatly reduce costs when the need for coiled tubing (CT), wireline (WL), or workover rig (WOR) is no longer needed on location to convey perforating guns.
However, when injection rate through the toe valve is not adequate for wireline pump-down operations, or the toe valve fails to open at all, the operator must revert back to conventional methods of perforating in order to achieve injection into the well and begin the frac operation. These failures immediately negate any of the cost savings the toe valves were designed to provide. This paper will review cost effective solutions, through the use of abrasive perforating, to quickly and efficiently perforate the toe stage and minimize non-productive time (NPT).
Most often, adequate pump-down rate is not achieved through the toe valve when debris or cement is lying across the tool, preventing it from opening or plugging off the ports. Prior to perforating, a motor and bit run is common to verify that the well is clean down to plug back total depth (PBTD). This requires a minimum of two round trips with coiled tubing or a workover rig. Two different methods of abrasive perforating have been used to benefit both conventional plug and perforate and frac sleeve completions (sometimes referred to as “baffles”). Several case histories will be presented to explain how a single trip in hole, utilizing a motor BHA and abrasive perforator in tandem to clean and perforate the toe stage, can minimize costs compared to several round trips using the conventional method with perforating guns. Additionally, we will explore an innovative approach to abrasively perforate the toe stage through frac sleeves where minimal ID's pose a problem with conventional methods of perforating.
Abrasive perforating technology, in conjunction with other innovative tools, adds a wide range of flexibility for today's complex horizontal wells. Utilizing this technology, problems such as toe valve failures can be addressed in a safe and cost effective manner.
Two Decades of Wireline Tractor Experience – One Operator Perspective From the Norwegian Continental Shelf
Authors: Buchanan Alastair , Koldal Hans Morten , Sælensminde Thor 
Published: March 2015

Abstract
Electric wireline tractor conveyance technology was introduced to Statoil operations in Norway in the mid 1990′s. Uptake was rapid and the technology offerings expanded to include ‘powered mechanical’ services run in conjunction with wireline tractor conveyance – further development and expansion of these services is on-going. This development is to a large extent reflected in global oilfield operations with widespread acceptance and application of these technologies.
Since 2008 a detailed record has been maintained of wireline tractor operations and runs for Statoil operations. This database is used to rapidly identify reference operations for on-going activities but also serves as a source of statistical information useful for strategic planning. The database is currently populated with information on over 900 separate wireline tractor operations and over 3000 individual runs – the vast majority of the data is from operations in Norway with some additional activity in Brazil and on US land operations.
There is a large, and growing, collection of technical papers addressing the technology and operations related to wireline tractor and related services. Most of these publications refer to specific technology descriptions and individual, or collected, case histories. With the aforementioned database of information we believe that there is a good basis for providing a more ‘holistic’ review of the results of applyling tractor and related technology – at least within the context of Statoil drilling and well operations in Norway.
This paper will: Discuss the introduction and uptake of tractor related services within the historical context of Statoil operations in Norway.Provide context in terms of the reservoir, well and operational environments encountered on Statoil operations in Norway.Provide a statistical overview of the applications of wireline tractors and related technologies for Statoil in Norway.Discuss the success rate of various applications of the technology within the context of Statoil operations in Norway.Discuss future challenges and opportunities.