bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Alternative Water Sources on Formation and Proppant Pack Damage Reduction Properties of Near-residue-free Fracturing Fluid
Authors: Russell Aaron , Singh Dipti , Schnoor Eli 
Published: June 2014

Abstract
This paper examines how the use of high-salt-content waters (i.e., produced and flowback water) in conjunction with a recently developed, virtually residue-free (res-free) hydraulic fracturing fluid affects the cleanup properties of the system. The res-free fluid system is designed based on a naturally low residue polymer that, when breaking, causes significantly less damage to the formation and proppant pack compared to conventional guar-based fracturing fluids.
Since its introduction, guar-based fluid technology has grown to dominate the hydraulic fracturing industry because of its reliability and cost-effectiveness. However, guar gum contains a significant amount of insoluble residue that is not removed during its processing. The residue can cause damage to both the proppant pack and hydrocarbon-bearing formation when the broken fluid is flowed back following the fracturing treatment. This damage can impair hydrocarbon flow from the formation and through the propped fracture, resulting in lower production over time. The res-free fluid offers better cleanup when breaking than guar-based fluids; therefore, it offers significantly higher proppant pack conductivity and formation permeability in laboratory testing.
The res-free polymer exhibits sensitivity to certain ions present in the solution, both in terms of gel hydration and crosslinking behavior. Depending on the ions present in the water and their respective concentrations, manipulation of the crosslinked res-free fluid system chemical formulation can mitigate these effects and achieve a stable, highly viscous fluid suitable for hydraulic fracturing. This paper investigates whether the necessary reformulations impact the regained permeability and conductivity of the fluid system. Rheological data demonstrating how the reformulated fluid compares to standard formulations is presented. Additionally, test results are presented highlighting the effects of alternative water sources on res-free fluid regained permeability and conductivity data.
The use of produced and flowback waters for fracturing operations can substantially reduce both the economic and environmental impact of fracturing operations. The combination of the res-free fluid's ability to use these water sources and its excellent damage-reducing properties provides a system with significant advantages compared to conventional technologies in many applications.
Breathing Second Life into an Old Well through Coiled Tubing Cement Squeeze for Brownfields in Malaysia
Authors: Khor Y. Y. , Ismail M. S. , Prahawinarto B. , Mohamad M. H. , Sin N. H. 
Published: June 2014

Abstract
BY, an offshore oil field discovered in 1976, has been in production since 1984. Several production enhancement activities were continuously conducted throughout the production life of the field. This includes surveillance works to arrest the production decline and enhance the oil recovery.
A systematic investigation showed that a few wells were having anomalous high water production despite being located at the crestal area of the reservoir. Further investigations revealed that poor cement bonding behind the casing was the main cause of high water production in the up-dip wells. With this new information, an evaluation of the remaining reserves was carried to justify any remedial well work required to reactivate the wells.
A coiled tubing cement squeeze job was identified at BY field to unlock the well potential of the watered out well located at the crest of the reservoir. The well, WELL-X has been idle for over 20 years due to high watercut. After a successful job execution, the well was able to flow with more than 1000 STB/D at 0% water cut. This has opened up more opportunities for idle well reactivation of other idle wells with similar high water cut due to cement channelling issues behind casing.
This paper presents an established workflow and optimization cycle adopted in BY highlighting the methodologies/techniques used to identify potential production opportunities that may have been overlooked in a brownfield and a recommendation on the way forward. The systematic workflow applied displayed success in a well using rigless intervention and has achieved economic return in a short time.
Improving Coiled Tubing Operational Capabilities to Overcome New HP/HT Challenges in Mexico Offshore
Authors: Solis Ulises , Perez Jose , Franco Ernesto , Ortega Ruben , Marin Marlon , Murillo Andrea , Reichert Bruce , Grimaldo Carmen 
Published: June 2014

Abstract
Over the last years the oil and gas Mexican operator’s exploration and development programs are becoming more challenging due to the complex conditions where hydrocarbons are found today. One of the areas that have seen a decline on production over the years is the offshore. As an alternative to find new sources of oil that overcome the current production decline in the area, the operator is drilling new wells where the operational capabilities of the equipment are put out of their limits. These new wells are drilled at depths beyond the conventional 5,000-m (16,400-ft) with bottom hole pressures as high as 15,000-psi and temperature over 180°C requiring that the equipment providing the services over their producing life reach their own limitations and in some cases re-engineering of the design and process has to be done.
In some cases, minimum changes to the equipment or processes are enough; however, a service of such complexity as the use of Coiled Tubing (CT) requires a major review of all the components of the operation to be completed in order to reach the new targets without jeopardizing the safety of the operations and/or compromising the production of the well.
This paper details the CT string design criteria to reach the deeper vertical depths with high wellbore mechanical friction coefficients while withstanding high pressures; equipment selection, to allow greater CT length capacity on reel and higher pulling capacity on injector head; platform and crane specifications to withstand over dimensioned equipment, as well as, a case study to analyze equipment and CT string performance for interventions on these types of wells.
New Chemical Treatment Selectively Placed via Coiled Tubing to Isolate Depleted Upper Zone Allows for Access and Stimulation of Unproduced Lower Zone
Authors: Dashash Alaa A. , Malik Ataur R. , Mukhliss A. E. , Al Yaseen A. H. , Albuali M. , Haekal M. 
Published: June 2014

Abstract
Completed with 4.5 in tubing and 7 in Liner, the upper carbonate reservoir had previously been stimulated and produced until reaching its economic potential. To prolong the well life, the decision was made to permanently isolate the upper zone, then perforate, matrix stimulate and produce from the lower zone.
The challenge for this operation was that the existing upper zone had been stimulated, creating a large void behind the casing with known high fluid loss. It was determined that isolation with cement would have only a small chance of success due to the high leak-off in the previously stimulated reservoir. Also, this zone was at a 40° inclination, making it more difficult to place an uncontaminated cement plug with Coiled Tubing (CT) and clean out the cement after placement.
An inflatable packer was also considered to isolate the upper zone and perform acid stimulation on the bottom zone. The bottom-hole pressure and temperature (5,000 psi and 300°F) were beyond the operational limits of any inflatable element available in the region.
For this unique situation, a new method was designed and successfully implemented. The new approach included first filling the upper zone with calcium carbonate chips (CaCO3) to reduce or limit the fluid losses. Then, utilize CT to place a chemical isolation treatment. The product utilized was an organically cross-linked polymer (OCP) system capable of permanently sealing the target zone by forming a 3D rigid gel. It is effective for preventing water and gas flow in sandstone and carbonate formations from 100°F to 350°F (38°C to 177°C). A benefit of the treatment was the ease at which it could be pumped and placed via CT and then cleaned out. All that is required for cleaning is a nozzle and jetting action. The implementation of this chemical sealant procedure provided reliable zonal isolation of highly depleted upper zone and allowed full access (with CT, Slick Line and E-line) to deeper productive lower zone. The successful chemical isolation in this well has resulted in avoidance of expensive workover operations.
This paper discusses the pre-job planning, benefits, challenges, design, execution, evaluation and lessons learned for applying this novel isolation method.
Next Generation of Battery Operated Electromechanical Setting Tools Increases Reliability at High Temperatures
Authors: Zbitowsky Ron , Al-Buali Mustafa , Clemens Jack , Denmon Michael , Dove Johnny , Gordon Scott 
Published: June 2014

Abstract
As exploration wells reach new depths and environments previously unexplored, the need for intervention services at higher temperature becomes a critical decision point for the entire drilling and completion process. Traditionally, the ability to set wellbore devices at elevated temperatures relied heavily on electric line services due to the higher temperature rating of explosive setting tools or surface powered electromechanical devices. This, of course, relied heavily on the availability and logistical expediency of units, tools, and personnel to avoid any nonproductive time, which could result in costly delays. An alternative would be using drill pipe; however, this could result in an excessive number of hours being added to the intervention process, increasing the overall costs to the developer. Due to these factors, companies continue to try to develop cost-effective intervention solutions while increasing reliability when operating in more hostile environments. Memory tools are fast becoming a favorable and more economic option.
Battery operated electromechanical setting tools have been around for many years and continue to evolve. The latest generation of setting tools has allowed advanced memory and command logic to be incorporated, providing more flexibility in the intervention routine as well as a thorough understanding of the recorded downhole event. The tool also has the added feature of a flasking system, allowing a much greater operating envelope when exposed to high downhole temperatures. This makes the use of an alkaline battery powered setting device, deployable via a multitude of conveyance methods, a safer and more cost-effective method.
This paper will review the new features and designed uses of this industry respected tool. Case histories with the device to complement intervention needs and operational planning convenience will be submitted to support the inherent value added to the oil and gas industry.
Electric Line Tractor-Based Conveyance in High Temperature Wells: A Collection of Local Case Stories
Authors: Peoples Matt , Hammill Tim , Alferez Olivier , Murrill Gary 
Published: June 2014

Abstract
Texas and Louisiana are not typically thought of as extreme environments, but the Haynesville and the Eagle Ford do have some hot and deep areas that are being developed. High temperature environments require specialized, robust intervention tools designed to withstand longer periods of extreme heat.
The industry’s definition for ‘high temperature’ ranges from 300°F to 400°F. Working in this environment requires careful preparation, as well as proven, reliable service providers and equipment. Established electric line tractor-based technologies running on AC power, as well as DC equipment have proven their application in these harsh and unforgiving environments. They offer additional benefits like reduced personnel and less heavy lifting, making these technologies inherently safer.
This paper will share the learnings from a number of local operations in which this electric line technology has been deployed, including advances with DC electronics and some examples of AC electronics cases ranging from conveyance of logging tools to plug and perforating for fracture stimulations.
In addition, this paper will examine the differences between AC and DC electric line equipment, their application in high-temperature environments, as well as discuss current trends within electronics for electric line equipment and future outlook for high-temperature equipment.
Use and Placement of Resin Blends to Effectively Isolate Existing Perforations when Fracture Stimulated Productive Horizons are below Existing Perforations: A Case History from the Middle East
Authors: Sierra Leopoldo , Noguera Jose 
Published: June 2014

Abstract
Hydraulic fracturing is the preferred method for enhancing production rates and hydrocarbon recovery, as well as for maximizing the productivity of conventional and unconventional reservoirs. To optimize the effectiveness of the treatment and maintain wellbore integrity, the stimulation process should be designed and executed with both the wellbore configuration and target formations in mind. For wells in which multiple fractures are required, stimulations are normally performed sequentially, from the bottom layer to the top layer; however, open perforations above the target zone (whether fractured or not) can present significant challenges during the stimulation process. For these cases, the preferable solution has been to isolate the perforations using the cement-squeeze technique, but this process is not completely effective because of short penetration. The fragility of the cement slurry under typical stress cycles associated with the fracturing process or the complexity of the process could compromise the existing perforation integrity and the effectiveness of fracturing the lower zone. Alternatively, the well can be recompleted to isolate the zone mechanically, though this involves a rig operation, which, in zoned areas, is not cost-effective.
One effective method to isolate existing perforations and help ensure deeper penetration of the isolation system without pulling out of the completion is squeezing a resin-based system with sufficient plasticity to maintain the isolation integrity under normal stress cycles. This paper documents the first application of resin blends to isolate existing perforations for the fracture stimulation of deeper prospective horizons. This isolation and stimulation process follows these steps: (1) the resin blend is squeezed into the wellbore using coiled tubing (CT); (2) the remaining resin blend is cleaned up using CT and a pressure test is performed; (3) the deeper horizon is perforated; (4) a minifrac and temperature survey are performed to evaluate existing perforation isolation; and (5) the fracture stimulation and production evaluation are performed.
Recent Developments to Coiled Tubing Equipment Design Improves Efficiency and Safety
Authors: Thomson Iain 
Published: June 2014

Abstract
To meet the demand for energy, operators are turning to development of unconventional resources. It is estimated that there are more than 750 trillion cubic feet of technically recoverable shale gas and 24 billion barrels of technically recoverable shale oil resources in discovered shale plays in the US alone. Tight rock in the longer horizontal shale-oil plays requires both longer lateral wells and multistage fracturing to maximize oil recovery. Coiled tubing (CT) plays an essential role in post-frac cleanup, requiring both safe and efficient equipment.
Unconventional shale well construction has taken on a factory construction approach, with more than 20,000 horizontal wells being drilled each year in the US. These long lateral lengths require larger CT units (CTUs) with larger outside diameter (OD) strings, which often increases the number and size of the equipment loads necessary to service the wells. Service providers are being challenged with ways to increase the speed and efficiency of these larger service packages, while maintaining or improving safety performance.
This paper discusses how the unique design of a mast unit trailer and associated equipment meets this challenge with its 5 1/8-in. preassembled well control equipment (WCE) stack and its ability to contain a full milling assembly combined with a fluidic oscillator in its riser stack. The system has also been designed to be versatile and enables a variety of WCE sizes and configurations to be mounted on the trailer to help ensure customized solutions to many operational challenges.
The system offers substantial improvements in terms of rig-up time compared to a conventional CTU. Field trails have shown the preassembled WCE stack can significantly reduce rigup time by as much as 50% by reducing the number of bolts required to be made up and torqued on site.
The paper also explains how the unique design improves operational safety. With the reduced number of bolts required to be made up onsite, hand and finger injuries associated with hammer wrenches and dropped objects can be vastly reduced.
When the trolley is raised and latched into position, dangers associated with making up a bottom-hole assembly (BHA) directly under a suspended crane load have been removed. Even if the crane were to fail, the mast and trolley is designed to sustain the entire load of the injector, stripper, riser, and blowout preventer (BOP).
Coiled Tubing Operations on a Multi-Service Vessel for Deep Water Well Interventions in the Gulf of Mexico: A Decade of Experience
Authors: Rudnik Alexander , Torres Carlos Alberto , Ottolina Renny Alexis , Rourke Jonathan , Barber David 
Published: June 2014

Abstract
Demand for subsea well intervention work has continued to be strong for the last 10 years. Even though subsea well interventions from an intervention vessel represent only a fraction of the total well workover activity in the Gulf of Mexico (GoM), its operating environment poses challenges in meeting economic goals for the Operators. The Q4000, a purpose-built, multi-service dynamically positioned (DP) vessel, was first introduced in the GoM in April 2002 and has been extensively used to meet demand of subsea well intervention and abandonment. Coiled tubing (CT) intervention, along with Slickline and Electric Wireline, has been instrumental in supporting the Q4000 ability to maintain safe, reliable, and cost efficient subsea through tubing well interventions in such a demanding operating environment.
This paper will summarize the operational experience and will focus on the CT-specific best practices and lessons learned that have resulted from over than 10 years of continuous operations on the Q4000. The document will highlight critical stages in the learning curve, standardized procedures, synergies between the CT and the Q4000 crews, and their impact on safety, efficiency and cost reduction. The paper will also discuss the needs for further improvements that will be required to meet the new challenges that subsea well intervention will be facing in the future.
Challenging Through-Tubing Intervention Succeeds Despite Extreme Well Conditions
Authors: Colmenares Franklin , Lopez Andres , Qutob Anas 
Published: June 2014

Abstract
The subject well, located onshore in the Kingdom of Saudi Arabia, had approximately 9,000 ft of 2.00-in coiled tubing lost in the wellbore, and was requiring thru-tubing intervention to recover the parted string and subsequently abandon the well. The string was lost following a failed cementing operation that left the string stuck due to 2,000 ft of cement inadvertently setting in the coiled tubing-production tubing annulus. Additionally, the lost coiled tubing had an inconel fiber optic cable (IFC) running through it, which presented an additional challenge in recovering the tubing from the wellbore. Downhole conditions were extreme, with 42% hydrogen sulfide and 10% carbon dioxide emitting from the wellbore. Operational conditions were also a major constraint, as the drive fluid was mud with 16% solids content, along with mud which had "packed off" in the coiled tubing-wellbore annulus. These factors created great challenges, and meticulous planning and execution was required to prevent critical well-control problems throughout the intervention operation.
The operation began with a rig-less coiled tubing operation to polish the top of the "fish" and permit access for a fishing assembly to begin recovery of the string. This was followed by the deployment of a workover rig to provide a more effective and time-efficient platform to recover the string. Following the string recovery, the 4.5-inch heavy-walled tubing required severing to commence the abandonment process. This paper will describe the challenging operation to recover the coiled tubing from the wellbore and sever the heavy-walled tubular, with all cautionary measures taken to mitigate well-control hazards and avoid lost-time safety incidents.
The operation was concluded with most of the string recovered without any lost-time incidents. More than 62 runs were conducted, both rig-less and rig-supported, with the IFC coiled tubing string being recovered in 100- to 500-foot sections. Despite the heavy mud and high solids content, the heavy-walled tubular was cut successfully using a hydraulic cutter, which allowed for its subsequent recovery.
Given the extremely sour down-hole conditions, along with the multiple challenging operational factors, this case presents an application with a unique set of unconventional circumstances which usually prohibit the successful recovery of lost strings. This case also demonstrates how careful planning, round-the-clock technical support and effective execution were the cornerstones of a successful intervention with extremely challenging conditions.
Steel Coiled Tubing Defect Evaluation Using Magnetic Flux Leakage Signals
Authors: Liu Zhanke , Minerbo Gerald , Zheng Andrew 
Published: June 2014

Abstract
Mechanical defects, such as manufacturing imperfections, grinding marks, corrosion pits, slip marks, kinking, gouges, etc, whether occurred in the factory or in the field, can be readily found on CT strings. Extensive studies have demonstrated the detrimental effects of mechanical defects, over the integrity of the coiled tubing, both in the lab and in the field. Researchers in the field have been proposing theoretical models for the severity assessment of mechanical defects, particularly as it relates to the remaining fatigue life. For such models, the defect sizing is usually a prerequisite. In order to improve coiled tubing pipe management, it is important to assess the size of a defect, and its severity.
MFL (magnetic flux leakage) based devices are volumetric and non-contact technology that is now commercially available for inspection and monitoring of CT strings. These devices have been demonstrated to be sufficiently sensitive in identifying mechanical defects. However, defect characterization and evaluation based on the devices’ MFL signals is rarely seen. To fully utilize these MFL based inspection devices for coiled tubing pipe management, it is important to establish correlation between the MFL inspection signals and the geometry and severity of the underlying mechanical defects.
The current work developed a three dimensional Finite Element Analysis (FEA) model to calculate magnetic flux leakage for mechanical defects on steel coiled tubing. The fidelity of the FEA model was verified against analytical and experimental results over a series of benchmark defects. By using the analytical and FEA models, parametric studies were performed to evaluate how the MFL signals are affected by various factors. The results were used to identify defect geometry features based on MFL signals. Physical limits behind these results were identified and analyzed. Ways to overcome such limits were proposed. Further, a novel approach was presented and validated to reconstruct three-dimensional MFL field based on a single MFL component measurement. The benefit of using multiple MFL components was demonstrated for defect characterization.