bluuebunny/crossref_metadata_2025_split huggingface dataset:
Benefits of Remote Activation and New Downhole Tool for Pinpoint Coiled Tubing Stimulation Technology
Authors: Pawar Bharat , Hriscu Joseph , Brand Shannon 
Published: March 2015

Abstract
The global demand for energy has led to an industry focused on increasing process efficiency with respect to innovative techniques for hydraulic fracturing stimulation. One such innovative process is coiled tubing (CT) deployed pinpoint stimulation. Pinpoint multistage fracturing with hydrajetting perforation technique is a solution that enables fracture placement in virtually an unlimited number of fracturing stages in long lateral sections, with a single trip into the wellbore. The evolution of pinpoint stimulation technology and its benefits have been recognized in many papers published along the years.
In some variations of the pinpoint stimulation technique, the bottomhole assembly (BHA) is activated by ball drop and reverse circulation of the ball. This process has been improved with a new generation design of the BHA, which renders the operation capable of being entirely controlled remotely from the surface using movement of the CT string. The ball drop activation is eliminated. This allows real-time, on-demand control of the tool setting. Based on traditional proven pinpoint solutions and adopting this new way of well stimulation, the pinpoint multistage fracturing method has become more efficient. This improved BHA, in conjunction with a proprietary pinpoint stimulation process, can help reduce water consumption on location and horsepower requirements, reduce idle time between fracturing treatments, reduce pump time per stage, and help prevent ball drop difficulties, all without having to make changes to the fracturing spread, equipment, and CT on location.
The improved BHA enables hydrajet perforation, hydraulic fracturing using real-time downhole proppant concentration control, and proppant plugs to be set for zonal isolation. Additionally, multicycle sequences can be repeated in long lateral and vertical wells. It also helps assist centralization of the BHA during perforating operations to help maintain appropriate jet standoff distance.
This paper presents the development approach of the aforementioned improved BHA, and a means to manipulate it from the surface. Validation during field testing is also outlined.
Performing Riserless Subsea Operations Utilizing Coiled Tubing in Open Water
Authors: Lasseigne Beau , Lindsey BJ , Larke James 
Published: March 2015

Abstract
Due to the versatility of modern coiled tubing (CT) operations coupled with the increasing demand for deepwater activity, CT is becoming a common conveyance method to perform subsea operations without the need of a marine riser or lubricator connected to the subsea wellhead. These operations utilize the CT string as an umbilical deployed through the moonpool of a dynamically positioned multi-purpose support vessel (MSV) to provide a variety of services to the operator without CT entering the wellbore. Without the need for a conventional deepwater rig or riser-based vessel, operations utilizing CT as an umbilical become a valuable time- and cost-saving option to perform subsea intervention work. Job objectives include well stimulation, lower zonal abandonment, subsea dispersant application, subsea equipment testing, flowline intervention, and hydrate-preventative blowout preventer (BOP) flushing.
From 2008-2012, an average of one CT umbilical job per year was performed. The method has increased in popularity and over the past two years, nine CT umbilical operations have been successfully completed. These successful operations include supplying nitrogen gas subsea to perform leak detection testing, utilizing dual CT umbilical strings to perform subsea BOP flushing as a pump down and return line, nitrified acid stimulation treatment, flowline hydrate removal, flowline purge to platform, and cementing zonal abandonment.
The combination of increasing deepwater technology and the adaptability of CT increases intervention and testing methods for operators. This paper will explain the techniques used, system improvements (both operational and HSE), and it will provide an overview of various types of jobs performed.
A Field Case History of Sulfate Reducing Bacteria Attack on Coiled Tubing Bias Welds - Root Causes and Remediation
Authors: Seal Clark , Padron Tomas , Mallanao Genesis , Maddy Tim , Craig Steven 
Published: March 2015

Abstract
Historically in our industry there have been many anecdotal claims of premature coiled tubing pipe failures during plug milling operations with recirculated fluid. Many of these failures shared related failure characteristics but no root cause was believed to have been identified by the service companies involved. In 2013, for one particular client, a series of failures on the coiled tubing string bias welds was observed, with a root cause due to the presence of sulfate-reducing bacteria (SRB) in the recirculated water. Two different mechanisms were identified as causing the premature failures on the bias welds: high-pressure corrosion fatigue that started at severe internal pitting caused by the presence of bacteria, and sulfide stress cracking caused by the SRB producing H2S.
A detailed analysis was also completed of time periods where fluid was spent stagnant in coiled tubing during rig-down/rig-up operations. Procedures were adjusted accordingly to prevent failure from further exposure to similar conditions by modifying recirculated fluid-handling volumes, improved biocide use, and rigorous multicomponent inhibition and purging during and between jobs.
Several specialist colleagues, familiar with SRB corrosion, were surprised at the speed SRB formed and created problems in coiled tubing in these environments. During the investigation process a rigorous fluid-testing protocol was developed. A prevention procedure was implemented during coiled tubing plug milling operations in this field. Afterward, no further coiled tubing failures were observed during similar operations in this area.
These failures have an industrywide impact in terms of personnel safety, operational disruption, and the cost and inconvenience of replacing coiled tubing strings. Information regarding coiled tubing failures related to bacteria exposure is only recently being published in our industry (Sherman 2014, Sherman 2015, Edillon 2015). Establishing the causes of these pipe failures and developing a procedure to minimize and/or eliminate their recurrence will allow safer operations for everyone involved in these operations. This paper presents the characteristics of these failures and the corrective actions taken to prevent further failures in coiled tubing exposed to similar conditions.
Modern Wireline Forces Modeling Using High-Impact Supplementary Utilities
Authors: Castillo H. , Smalley E. 
Published: March 2015

Abstract
With the increased popularity of long, deep and tortuous wells, mainly in high-cost operating environments, the risks associated with wireline logging operations and interventions in these modern complex wells have become more acute. Several risk-reduction technologies and forces-modeling software capable of simulating these operations have been developed and successfully applied.
This paper describes several high-impact supplementary modeling utilities that have been implemented within a leading forces-modeling software that enable users to adequately plan and execute complex wireline operations. The utilities are designed to perform dedicated analyses using the project data already included in the wireline operation models.
The following utilities are presented in this paper: Pump Down AnalysisCable Tension AnalysisFriction Coefficient AnalysisTool Depth Creep AnalysisStuck Pipe AnalysisStuck Wireline/Tool AnalysisTool Free Fall Analysis
The effective use of these utilities significantly reduces the non-productive rig time associated with recovery operations and can assist with optimizing pump down operations, accurate positioning of downhole tools, as well as locating tool strings dropped in the well. Use of the utilities can also improve the accuracy of wireline downhole conveyance models while enhancing the ability to perform high-tension operations in a safe and efficient manner. The economic value resulting from the use of these applications is directly associated with the aggregate daily rig cost and the financial cost of the resulting deferred production volume during non-productive time, which together can be in excess of a million dollars a day.
This paper provides descriptions and application examples of these supplementary wireline modeling utilities, the logic and calculations supporting them, and the resulting economic benefits they deliver.
Using Coiled Tubing to Safely and Efficiently Mill Out Composite Bridge Plugs Set Across Zones with Significant Differential Pressures
Authors: Li Yang , Terry Adrian , Parr Christopher , Stanley Rick , Dunsmore Braden 
Published: March 2015

Abstract
Coiled tubing (CT) is one of the most common and effective methods employed to mill out composite bridge plugs (CBPs) that are used to isolate zones during completion. Typically, the zones are normally pressured or over pressured, i.e., each interval approximately the same pressure. Recently, in a New Zealand field, a plan was set to mill out CBPs that had been set between zones that were tight gas and conventional with as much as 3,780 psi pressure differential between them.
One major challenge relates to the CT CBP milling. While milling the plug that isolates the over-pressured zones, the differential pressure can exert significant forces on the milling assembly, raising the potential for buckling/failure of the CT. To reduce this risk it was decided that a bridge plug with an equalizing path would be used to eliminate the large pressure differential and potential upward forces. Another challenge was the issue of cross flow between the zones after milling was completed, and the potential for well control issues due to some under-pressured zones that could not support a full fluid column, causing loss of hydrostatic pressure.
For the under-pressured zones, nitrogen was used to equalize the pressure across the plugs prior to milling them. To minimize the risk of getting stuck and potential CT failure, the operation was closely monitored and optimized by using a CT real-time downhole communication system. The real-time downhole pressure captured by the system during plug milling provided the firm evidence that equalization had occurred.
This paper reviews the selection of plugs/mills and the milling strategy for safely milling CBPs that have been set across zones with significant differential pressures. The benefits of using a CT real-time downhole communication system is discussed by illustrating the case study of successfully removing 25 CBPs with CT in the three wells within a field.
Application of a Biocide Water Treatment Program to Prevent Coiled Tubing Corrosion: A Case Study
Authors: Edillon Lemuel , McLeod Richard , Henderson Matthew A. , McVicar Warren , Eyre Kellen , Pelletier Robbie , Yao Shunyu , Yan James 
Published: March 2015

Abstract
From December 2013 to February 2014, a major Canadian coiled tubing (CT) service company experienced several premature CT failures that all occurred in the same geographic region of northeastern, British Columbia. The failed CT samples were analyzed both by the manufacturer and a third party to determine the failure mechanism. Upon inspection, internal corrosion on the base material and preferential corrosion of the bias weld filler material was, in multiple cases, determined to be the cause of failure. It was concluded that microbial induced corrosion (MIC) likely caused localized corrosion and pit initiation leading to crack propagation and sudden failure.
When MIC was identified as a potential cause of failure, the service company's engineering team initiated an extensive water testing program to determine a preventative solution. The base fluid used for CT operations in the specified geographical region typically consisted of produced water, often recycled multiple times from fracturing operations. The CT service provider was not responsible for the water supply, nor did it have historical information on the supplied water quality.
In several occurrences, the fluid tested positive for the presence of harmful acid producing, and sulfate reducing bacteria, which further supported the presence of MIC. To eliminate or minimize the potential for harmful corrosive bacteria, the service company implemented a biocide water treatment program.
The service company explored several methods of applying both liquid and powdered biocide establishing a best practice for pre-treating the supplied water and treating it throughout the operation. Field testing proved the application of biocide dramatically decreased bacteria count. To date the biocide treatment program has been successful and no additional premature failures due to corrosion have been recorded. This has allowed the engineering team to optimize biocide loadings and revise the CT retirement criteria.
While the subject of microbial induced corrosion in CT has been widely discussed and published throughout industry literature, the problem has not been prevalent among CT operations in Canada. This paper discusses a specific premature CT failure due to corrosion, an analysis of the base fluid in the area that was believed to cause the corrosion, and the biocide treatment program used to prevent similar CT failures in the future.
Coiled Tubing Inverted Gas-lift System Installation on the Norwegian Continental Shelf
Authors: Babayev Rufat , Sirevaag Bjorn , Grindheim Kjell Ivar , Kerr Scott , Sliper Britt 
Published: March 2015

Abstract
The Statfjord field was the first, and one of the largest, fields developed so far with Statoil as operator. The field was discovered by Mobil in 1974 and Statoil took over operatorship in 1987.
The field was developed with Statfjord A, B and C production platforms, which all have concrete gravity base structures incorporating storage cells. Statfjord A began production in 1979.
The field will remain in production until 2025 and possibilities to further expand the lifetime are being looked into.
One of the techniques that are being applied to rejuvenate some of the older wells is retrofit gas lift solutions.
In this paper detailed information on an Inverted Gas Lift System (IGLS) applied to a well on the Statfjord A platform will be presented. The IGLS solution included a solution to retain downhole safety valve functionality in the well and required qualification of a new type of coiled tubing material.
The following aspects of the project will be discussed in detail in this paper: Background and objectives.Method selection, planning and equipment qualificationOffshore operations for installation of the systemFollow up and results
Overcoming Extended-Reach Challenges for Annular Fracturing
Authors: Castro L. , Craig S. , Micheli R. , Livescu S. 
Published: March 2015

Abstract
More operators are seeing the production benefits of targeted horizontal annular fracturing. The most active method of annular fracturing in the USA involves ported sleeves installed with the completion and activated via an isolation packer. Initial operations were in lateral lengths of 2,000 to 3,000 ft. However, current operations are planned for accessing up to 10,000 ft laterals. Increasing lateral length results in the traditional access challenges faced by all coiled tubing (CT) operations. The traditional method of lubricant use is the primary option due to its simplicity. The second method is to use fluid hammer tools (FHT). These are industry standard for improving efficiency in composite plug milling operations, but their use in genuine extended-reach operations is not as broad.
This paper briefly covers historical ported annular fracturing operations and the various methods of achieving increased lateral reach. Results from four wells with lateral reach of 7,200 to 10,277 ft are detailed in the paper. The balance of the paper details operational results and optimization from several extended-reach wells.
Detailed lateral reach modelling was performed prior to all operations. This permitted the determination of the number of expected stages that would require the use of lubricant in the fracture treatment flush. Given that residual lubricant in the completion is removed by the erosion effects of the proppant in the fracture treatment, each stage would require an additional fluid flush. This gives an opportunity to modify the lubricant concentration, type, and volume in the flush. Before using fluid hammer tools (FHT) for setting the isolation packer, laboratory testing was performed to ensure the bottom-hole assembly (BHA) system compatibility.
The lubricant testing and initial field results were reported previously (Livescu and Craig 2014; Livescu et al. 2014a,b). This paper provides operators with sufficient case histories of the planned use of an advanced lubricant in genuine extended-reach wells in real life situations. This knowledge can improve operator confidence in drilling longer laterals for predictable access for annular fracturing operations.
Optimization of Matrix Acidizing With Fluids Diversion in Real-Time Using Distributed Temperature Sensing and Coiled Tubing
Authors: Medina Eber , Sierra Jose , Garcia Alexis , Gleaves Jorge , Mendez Josue 
Published: March 2015

Abstract
Carbonate formations in southern Mexico are commonly stimulated using matrix acidizing treatments to increase well productivity by removing near-wellbore (NWB) damage. Such damage can be attributed to accumulation of paraffin and asphaltene deposits during the productive life of the well and, in other scenarios, to fluid invasion while performing workover activities. A high perforation length across the reservoir to increase production from this highly natural-fractured carbonate has been the completion option for several years. The use of diverters is a common practice in the Bellota-Jujo field when multiple intervals are open. However, the effectiveness of the diversion had not been evaluated in real-time. A distributed temperature sensing (DTS) option was deployed to measure temperature profiles along coiled tubing (CT) equipped with an internal fiber-optic cable and a modular bottomhole assembly (BHA) consisting of pressure, temperature, and depth correlation sensors. This option was selected to monitor the treatment and help make real-time decisions.
This real-time fiber-optic (RTFO) integrated system used during the stimulation allowed identification of zones with higher and lower admission. Based on this information, decisions were made during the pumping schedule, modifying volumes and rates of diverting agents and stimulation fluids being pumped through the annular space between production tubing and CT, also pumping through CT using a fluidic oscillating tool optimizing the diversion process during different stages of the intervention. This system enabled the operator to correlate depth and continuously monitor the temperature changes across the producing zone of the well.
The findings and results of the stimulation treatment with this technique used in the well, Bricol 2DL, are presented in addition to the thermal analysis of the DTS profiles.
The use of the RTFO integrated system during a matrix stimulation treatment in a carbonate formation with high permeability contributed to successfully evaluating the effectiveness of the fluids and mechanical diversion resulting in a well productivity increase of 60%, thus keeping the well in production since the treatment was performed.
Local Use of Ankaferd Blood Clotter in Emergent Beating Heart Coronary Artery Bypass Grafting
Authors: Atalay Hakan , Atalay Atakan , Dogan Omer F. 
Published: March 2015

Background:
Severe beeding which requiring massive blood transfusion after emergent beating heart surgery is shown to be 1–3%. Therefore, complications and side effects of transfusion can be seen. The aim of this study was to investigate the effectiveness of Ankaferd blood clotter (ABC) as a new topical herbal blood clotter to decrease mediastinal bleeding in emergent beating heart CABG patients who medicated with clopidogrel and acetyl salisilic acite (ASA) prior to CABG surgery.

Materials and Methods:
25 CABG patients received a high dose clopidogrel (600 mgr) and 300 mgr ASA have been included into the study (ABC group). 25 patients have also been included into the study for comparison (placebo group, PG). After the administration of protamine sulphate, a 10 ml of ABC solution has been sprayed to the surgical area including mediastinum and epicardial sac. We compared mediastinal drenaige, reoperation due to tamponade, and required blood and blood products in both groups.

Results:
The mean amount of bleeding after operation was 230 ml in ABC group, and 490 ml in CG (P=0.001). In ICU, bleeding in ABC group and CG was 410ml and 680ml, respectively (P=0.0022). The mean total bleeding from mediastinum was 530±280 mL and 990±440 mL In ABC and CG group, respectively (P=0.001). The amount of autotransfusion was as follows: 175 mL in ABC group, and 290 mL in CG (P=0.002). No patient needed the surgical revision in ABC group, but four patients (16%) from CG group because of cardiac tamponade. Seventeen patients from CG required blood transfusion due to low hematocrite level postoperatively. In CG, the mean hematocrite level was 17±2,3. Transfusion of fresh frozen plasma and platelets in ABC group and CG were as follows: 0.2 and 0 in ABC group, and 0.3and 0.4 in CG.

Conclusion:
Our study showed that the local use of 10 mL ABC reduces bleeding significantly. Therefore, transfusion requirements of PRBC, platelets, and total blood units in patients on clopidogrel and ASA undergoing emergent beating heart CABG. To provide cardiac tamponade because of excessive mediastinal bleeding and requirement of blood transfusion after emergent CABG patients who previously administered clopidogrel and ASA, we propose local use of ABC solution as a potent coagulant agent.