bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prevent Fouling and Corrosion During Mill-Out Operations: Permian Case Studies
Authors: Galindo Tanhee 
Published: March 2019

Abstract
Case studies of mill-out operations in the Permian Basin which evaluate chemical programs and processes used. Results show how existing processes and chemicals used or lack thereof, can affect equipment and undo the preventative chemical treatments used during the hydraulic fracturing process. The study looks at field water testing performed during various mill-out operations and considered workover rig vs coiled tubing, equipment set up, water & chemicals used, and operational challenges. Water analyses were completed on the injection water and returns at various intervals of the mill-out. Effectiveness of chemical treatment was also monitored when biocide was used.
Field case studies of horizontal wells for two operators in the Permian Basin are presented. Wells were milled-out utilizing workover rigs or coiled tubing units. Testing results show the impact of equipment setup and operations process on the water quality and efficiency of the chemicals used. Water fouling was prevalent in all cases, with coiled tubing jobs showing the highest degree of water contamination and chemical inefficiency. Changes in the water treatment program during operations showed significant improvement and sustainable results. Potential corrosion of the work string due to water fouling and water composition were also observed. The effects of changes to chemical dosages were also monitored. This was important because it identified operational improvements that can reduce equipment replacement costs, reduce chemical overuse and help protect wells from fouling due to high bacteria. These case study provides a comprehensive review of mill-out operations, which provides guidelines for improving chemical efficiency and potential of extending life of the work string.
Case Study: Optimizing Milling Operations within the Canadian Montney Play
Authors: Lukye Blaise 
Published: March 2019

Abstract
The Montney Formation is a major shale gas and shale oil producing stratigraphical unit of Lower Triassic age in the Western Canadian Sedimentary Basin in British Columbia and Alberta. The potential resource is estimated at 449 trillion cubic feet of marketable natural gas, 14,521 million barrels of marketable natural gas liquids (NGLs) and 1,125 million barrels of oil. The hydrocarbon resource is unlocked using horizontal drilling followed by various fracture stimulation techniques from 25 to 75+ stages. As stage counts increase and lateral lengths are extended further to stimulate more formation, the challenges of efficiently completing a producing well is a continuous cycle of technique development and equipment improvements.
Hydraulic isolation between fracture stimulation stages is established using mechanical methods deployed as an integral part of the production casing string or inserted into the production casing string during the fracture stimulation. In the Montney, the method of ′′plug-and-perf′′ has been the predominant method of isolating stages. The method utilizes highly drillable bridge plugs pumped down and set on wireline followed by explosive jet perforating one or several ‘perf clusters’ during the same wireline run. These perforation intervals are fracture stimulated and the process is repeated for each stage until the lateral is fully stimulated. These drillable bridge plugs are then removed during the post-stimulation drillout phase of the completion to open the production casing for hydrocarbon inflow. This paper is a case study of a 62 well data set in a confined, highly productive area in the Montney resource play. The paper discusses progressive improvement methods and measuring efficiency of post-stimulation drillouts.
Effects of Particle Density on Hole Cleanout Operation in Horizontal and Inclined Wellbores
Authors: Pandya Soham , Ahmed Ramadan , Shah Subhash 
Published: March 2019

Abstract
Coiled Tubing (CT) is widely used in wellbore cleanout operations to remove solid particles such as drilled solids or residual proppant from the hydraulic fracturing treatments. The cleanout operation is often associated with inefficiency and substantially increases the operational cost. This study is aimed at developing a model to predict the required fluid circulation rate and time to efficiently remove solids from the wellbore and optimize cleanout operation.
To study the hole cleaning mechanism, solids bed erosion experiments were conducted using a flow loop that has a 10.4 m long annular (127 mm × 60 mm) test section. The effects of solid density, flow rate, inclination angle and fluid type on cleanout operation were investigated by measuring bed erosion and hole cleaning efficiency. A stable bed was initially formed in the annular test section of the flow loop. Once the setup was positioned at the desired inclination, the bed was eroded for 30 minutes at a constant flow rate. The amount of solids removed during each test was weighed to determine cleanout efficiency. A traveling camera system was utilized to measured bed height at different locations in the test section. The measurements resulted in the generation of bed erosion curve (average bed height versus circulation time plot) for each test. The trends are consistent with previously reported measurements; however, certain discrepancies were found when examining the trends.
This study indicates that solid density has a slight to moderate effect on hole cleanout operation. For a given flow rate, high-density solids make hole cleaning much more challenging, especially in near horizontal well sections. The critical angle of inclination that is defined as the angle at which cleaning is the most difficult was not significantly affected by the density of the solids. Irrespective of the density of solids, the effective cleanout fluid to be used in wellbore cleaning operation at all inclinations remained the same.
The outcomes of this investigation can be applied in the field to optimize cleanout operations in horizontal and deviated wells. The bed characteristics recorded during the investigation give more insight into the mechanisms of solids transport in inclined wellbores and can be used as the basis for further investigation.
Downhole Data Analysis for Pressure-Pulse-Generating and Axial-Oscillation Measurement Tool
Authors: Khan Alamzeb , Trinh Khoi , Thompson Patrick , Glaze Garrett , Forrester Stephen 
Published: March 2019

Abstract
High levels of drag, especially in horizontal and extended-reach operations, can be a major concern during sliding or rotating. Drag reduces drilling efficiency by requiring increased energy input, primarily through increasing torque and weight on bit, to achieve the desired rate of penetration (ROP). Reduced drilling efficiency results in excessive tool wear, lower ROP, and poor directional control. Of the several methods the industry uses to combat drag, the scope of this study was focused on the use of a pulse generator paired with a displacement generator, which makes up a drilling agitator tool (DAT). A DAT is commonly used in extended lateral formations to improve weight transfer to the bit in vertical and nonvertical drilling applications. The operational principal of the DAT is the production of a pressure pulse that causes a repetitive axial motion in a shock tool. This paper compares offset run data between two DAT cases—one run with a traditional DAT and the other on a new, efficient, "high-energy" DAT (HE DAT). The run performance in similar portions of vertical and horizontal sections was compared between the two systems.
This study was based on data collected from a pressure pulse and axial displacement data recorder from horizontal wells in the STACK play drilled by Devon Energy. The objective of this study was to observe the performance of the HE DAT and determine if there was a noticeable gain in performance in terms of drilling efficiency and ROP as compared to a standard DAT. These results are discussed in detail and supported by high-resolution data collected during drilling.
The data analysis presented here provides an in-depth look into the operation of the HE DAT's performance as compared to the standard DAT in a very similar offset well. Overall, a 20 to 25% increase in ROP with the HE DAT was expected, effectively validating the enhancements made to the tool. This study collected data using data recorders—novel, small, self-contained devices measuring axial vibration, internal pressure, temperature, and axial displacement—located directly above and below the DATs to make a comparative assessment and deliver information about drilling data that was otherwise not available via conventional downhole measurement tools.
Advancement in Wireline Tractor Design Reduces Operating Time and Improves Reliability
Authors: Lee Matthew , Singha Roy Sushovon 
Published: March 2019

Abstract
A newly developed wireline tractor (Fig. 1) is exhibiting positive effects for total operating time and reliability. Not only can it deploy a wide range of logging tools, well intervention tools, and explosives at a rate up to 100 ft/min (6,000 ft/hr) in horizontal or highly deviated wells, it has an efficient electro-mechanical design. Additionally, the tractor can run in wells up to 350°F and 25,000psi with full tractoring force.
Historically, wireline tractors were based on a lower efficient hydraulically powered design or additional electronics to invert voltages were necessary (Sheiretov 2016). Because of advancements in downhole-rated DC motors and electronics, it's possible to increase reliability while delivering more power with less parasitic losses (Fig. 2).Important design points for a tractor include: Efficient and robust electro-mechanical architectureCompatibility with single and multiconductor wirelinesControlled by a real-time telemetry system to log tractor and well data while tractoringPrecise control and feedback of tractor speed, torque, and wheel normal forceCombinable with a wireline release tool, swivel, casing collar locator (CCL), downhole tension, accelerometers, explosives safety device, and rollersFigure 1New wireline tractor.Figure 2DC voltage electromechanical drive system example.
The CCL, downhole tension, and accelerometer measurements assist with efficient tractor operations. The wheel normal force should be adjustable to the tractor through restrictions and completion components.
Enhanced Conveyance Method for Pipe Recovery Services with Wireline Tractors
Authors: Foucher Pierre , Damm David 
Published: March 2019

Abstract
A holistic approach was employed to develop a technique for conveying severing tools on wireline tractor. The objective is to establish a procedure to preserve the integrity of the tractor and related components of the toolstring.
Wireline tractors are sometimes required to convey pipe recovery services when the drillpipe becomes stuck and circulation is lost. In this case, the primary objective is to free the pipe in the lateral right above the stuck point. Pipe recovery services typically use a freepoint finder, detonating cord, and pipe cutter or colliding tool. This last option employs a high explosive load triggered in a specific manner to cause precise collision of the shock waves. Unfortunately, the explosion commonly damages the tractor used for conveyance.
A full experimental characterization of the downhole explosion was conducted to record all critical parameters that could physically damage the tractor. A dedicated special acquisition system was then used to measure experimentally the effect of a colliding tool conveyed on a tractor including pressure, shock, and strains.
In-depth analysis of the results was used to determine optimized operational guidelines and practices to achieve the objective of reliably conveying severing tools while preserving the integrity of the tractor and related logging tools. The technique relies on a cost-effective solution.
This method has been deployed to the field for successful application in the Middle East where it saved significant operational time and maximized the recovered pipe length without any damage to the tractor.
With this enhanced method, wireline tractors can convey pipe recovery tools with acceptable risk of damage to the tractor, which reduces operation cost. Overall, it significantly increases the confidence in using this conveyance option for pipe recovery services and minimizes potential downtime.
Rapid Deployment and Use of Snubbing Unit Brings Well with Underground Blowout and Surface Broaching Under Control
Authors: Donaldson Albert , Marrero-Reyes Victor , Scott William , Al-Mayyan Haitham 
Published: March 2019

Abstract
This paper describes the mobilization of a snubbing unit and blowout preventer (BOP) stack in the Middle East and their use to enable the control of a well with an underground blowout and surface broaching within a short time. The mobilization timeline is provided, along with details about how the snubbing unit and BOPs were integrated with existing equipment to enable re-entry into the blowout well. The procedures and equipment used to enable a stable rig up and well entry are discussed. The paper also describes the situation within the well and the procedures used to enable control. Changes to the original plan, the reasons for the changes, and the results are also described.
Mobilization, rig up, and testing were completed within 12 days of receiving instructions to proceed. The well was controlled and left in a safe condition within an additional 14 days. The original plan had to be continuously reviewed and modified as more information became available during the snubbing operation. The original plan was to slip and shear the holed completion out of the well under pressure; however, as described in the paper, this plan was not implemented. The rapid deployment and use of the snubbing unit brought control to a deteriorating situation. Snubbing provided the fastest option to gain control of this well with an underground blowout and surface broaching.
Practical Pipe Understanding and Limits
Authors: Newman Ken , Kelleher Patrick 
Published: March 2019

Abstract
There are aspects of pipe behavior and limits that can be confusing and counter intuitive. These include understanding the conditions under which a pipe will "buckle" and when the stresses in the pipe will reach a point where the pipe material "yields". The combination of forces, pressures, torque and bending moments that are being applied to the pipe may make it difficult to understand how the pipe will responding. The objective of this paper is to clarify some of these issues and demonstrate a simplified calculation tool for field engineers to use when critical decisions need to be made quickly.
Composite Plug Removal With E-Line Milling Solution in Argentina
Authors: Aguilar Gary , Audelo David , Nebiolo Martin , Jimenez Facundo , Waigel Ruben , Canales Fernando , Martinez Joel 
Published: March 2019

Abstract
In March 2018, an electric wireline (e-line) milling solution was deployed to remove a composite plug in an unconventional well in Argentina. This abstract details the planning and execution of the first composite plug removal with an e-line milling solution in Argentina.
Plug and perf hydraulic fracturing operations were halted when a composite plug became stuck in the in 5" × 21.4 lb/ft casing at 2,442 m MD in the vertical section of an unconventional well. The operator initially considered mobilizing coil tubing (CT) to mill the plug, however time constraints drove them to explore more efficient alternative options. The availability, short mobilization time, efficient rig up, and past successes of an e-line tractor and milling assembly demonstrated a clear advantage versus CT for this application.
The objective for the milling operation was to remove the composite plug and confirm unrestricted access to the next perf stage at 4,252 m MD. The successful plug milling operation on the 1st run required approximately 9.5 hours of milling. Over the next 11 hours, two additional runs with heavy milling at different depths were required to clear a path to the target depth. The use of this solution allowed the operation to continue as per the program without further interventions.
An e-line milling solution for composite plugs and other wellbore hardware is an efficient and cost- effective alternative to conventional methods. Additional benefits include a substantial decrease in HSE risk exposure by minimizing the operational footprint through a reduction of personnel and equipment.
Instrumented and Surface-Controllable Nonexplosive Mechanical Punching of Downhole Tubulars
Authors: Wurtz Joshua , Dresel Matthew , Giem Greg 
Published: March 2019

Abstract
An instrumented, powered, and nonexplosive mechanical punching system with full surface control is presented to demonstrate the benefits and limitations of such systems versus traditional explosives and/or nonpowered mechanical punching systems. The paper will consider design criteria, performance, real-time outputs, flow areas, and operational risk factors when evaluating the different punching systems.
The oil industry has run many forms of explosive and nonexplosive punching or perforating assemblies in wells over the years. As well design and complexity have changed over time, so has the need for punching and perforating methods.
An instrumented and surface-controllable, nonexplosive mechanical puncher is the needed change in downhole punching and perforating methods for increasingly complex well designs. Such a system is seen as a safer, more reliable option than traditional methods, and it provides immediate feedback on the operation. Additionally, during punching operations, the system significantly reduces the risk of damaging control lines directly behind a tubular and eliminates the risk of damaging annular tubulars.
Unique design factors and mechanisms were evaluated and characterized to develop an optimized instrumented and surface-controllable, nonexplosive mechanical puncher system.
Puncher materials and geometries were evaluated for durability, forces required to penetrate a tubular, and flow areas generated. These punchers were characterized in multiple tubular sizes and grades to determine the relationships between tubular changes to changes in the same durability, forces, and flow areas.
It was seen that different puncher types and tubulars have varying operational risks, durability, forces required to penetrate, and total flow areas generated. This information can be used to optimize a puncher to the operational objective. Additionally, through instrumentation, it was seen that there is repeatability in punches performed, and a successful "shot" and potential puncher wear can be determined.
It was also seen that the system reduces risk in several areas. When compared to punching with explosives, there was no tubular swell at the perforations nor internal perforation burrs or damage. The system was punched directly into a downhole pressure gauge line behind the tubular with no damage observed to the external line after the punch hole was made. Finally, it was seen through surface control, powered options could be used to reduce any sticking risks.
The novelty of the instrumented and surface-controllable, nonexplosive mechanical puncher system is in the engineering, design, and characterization of the system to provide an optimized, more reliable, and more efficient downhole punching system. In addition, there is value in knowing in real time the status of the operation, downhole diagnostics, and allowing of surface controls for risk management and additional contingencies.
Lower rate of delayed graft function is observed when epidural analgesia for living donor nephrectomy is administered.
Authors: Baar Wolfgang , Goebel Ulrich , Buerkle Hartmut , Jaenigen Bernd , Kaufmann Kai , Heinrich Sebastian 
Published: March 2019

Abstract
Background The beneficial effects of epidural analgesia (EDA) in terms of pain control and postoperative convalescence are widely known and led to a frequent use for patients who underwent living donor kidney nephrectomy. The objective of this study was to determine whether general anesthesia (GA) plus EDA compared to GA only, administered for living donor nephrectomy has effects on postoperative graft function in recipients.
Methods In this monocentric, retrospective cohort analysis we analyzed the closed files of all consecutive donor- recipient pairs who underwent living donor kidney transplantations from 2008 to 2017. The outcome variable was delayed graft function (DGF), defined as at least one hemodialysis within seven days postoperatively, once hyperacute rejection, vascular or urinary tract complications were ruled out. Statistical analyses of continuous variables were calculated using the two-tail Student’s t test and Fisher exact test for categorical variables with a significance level of p<0.05, respectively.
Results The study enclosed 291 consecutive living donor kidney transplantations. 99 kidney donors received epidural analgesia whereas 192 had no epidural analgesia. The groups showed balanced pretransplantational characteristics and comparable donors´ and recipients’ risk factors. 9 out of all 291 recipients needed renal replacement therapy (RRT) during the first 7 days due to delayed graft function; none of these donors received EDA. The observed rate of DGF in recipients whose kidney donors received epidural analgesia was significantly lower (0% vs. 4.6%; p=0.031).
Conclusions In our cohort we observed a significantly lower rate of DGF when epidural analgesia for donor nephrectomy was administered. Due to restrictions of the study design this observation needs further confirmation by prospective studies.
Effects of intraoperative PEEP on postoperative pulmonary complications in patients undergoing robot-assisted laparoscopic radical resection for bladder cancer or prostate cancer: study protocol for a randomized controlled trial
Authors: ZHOU Zhen-feng , FANG Jun-biao , CHEN Long , WANG Hong-fa , YU Yong-jian , WANG Wen-yuan , CHEN Jia-bao , ZHANG Miao-zun , HU Shuang-fei 
Published: March 2019

Abstract
Background: There are increasing studies shown that the use of a lung-protective ventilation strategy has a lung protection effect in patients undergoing abdominal surgery, however, the appropriate PEEP has not yet defined. Adopting a suitable PEEP may prevent PPCs. Robot-assisted laparoscopic surgery is the newest and most minimally invasive care for bladder cancer or prostate cancer. It is also necessary to consider the effects of trendelenburg position with pneumoperitoneum (PnP) on airway pressure and pulmonary function. The role of PEEP during the intraoperative period in preventing PCC for robot-assisted laparoscopic surgery is not clearly defined. Methods/design: A total number of 208 patients undergoing robot-assisted laparoscopic radical resection for bladder cancer or prostate cancer will be enrolled and randomized into a standard PEEP (6-8 cmH2O) group and a low PEEP (≤ 2 cm H2O) group. Both groups will receive an inspired oxygen fraction (FiO2) of 0.50 and a tidal volume of 8 ml/kg ideal body weight (IBW). Standard perioperative fluid management standardization and analgesic treatments will be applied in both groups. The primary endpoint was postoperative pulmonary complications within 7 days after surgery. Secondary endpoints will be: the modified clinical pulmonary infection score (mCPIS), postoperative extrapulmonary complications, postoperative surgical complications, intensive care unit (ICU) length of stay, hospital length of stay, thirty-day mortality. Discussion: This trial is aimed to assess the effects of low tidal volumes combined a intraoperative PEEP ventilation strategy on postoperative pulmonary complications in patients undergoing robot-assisted laparoscopic radical resection for bladder cancer or prostate cancer.