bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real-Time Underbalance Perforating in Subhydrostatic Reservoir Improves Long-Term Well Performance: A Case Study of Well Injector in Malaysia
Authors: Keong Azwan , Yong Nigel , Djanaka Pramudya 
Published: March 2019

Abstract
One method of sustaining and optimizing a well through its lifetime is underbalance perforating. When hydrostatic pressure inside the wellbore at the zone of interest is kept at less than the expected reservoir pressure, the damaged and crushed zones across the critical matrix at the reservoir that cause low permeability in the perforation tunnels will be immediately cleaned up as soon as communication to the reservoir is established upon perforating. In an operation offshore Malaysia, underbalance perforating was performed in injection wells, rather than producing wells, to optimize injection rates. The operation employed a fiber-optic firing head deployed on a fiber-optic coiled tubing (CT) real-time telemetry system.
The most common and effective method to achieve underbalance is displacing the well to a lighter fluid, less than the water gradient, prior to perforating. Subhydrostatic wells with low bottomhole reservoir pressure pose challenges to achieving the underbalance state. For these wells, well fluids must be removed via nitrogen displacement and the completion perforated with a nitrogen cushion. After underbalance is reached, the well is ideally ready to be perforated as it is, without introduction of additional fluids.
In the offshore Malaysia field, water injector wells had been perforated overbalance because the objective of the wells was injection and not production. However, the injection rate of these water injectors started to decline below the optimum design rate only after a short period, thus affecting the production rate of the neighboring oil and gas producers. Two pilot wells were designed to be perforated underbalance, achieving immediate cleanup after firing. The challenge was to perform an underbalance perforation in a low-pressure, depleted reservoir, using nitrogen as a displacement fluid. After this condition was fulfilled with a 500-psi differential, the well was to be perforated without any liquid introduction to activate the guns, which restricted the use of pressure- and ball-activated firing heads.
The fiber-optic-enabled firing head deployed on CT with real-time telemetry system is considered the most efficient intervention approach to overcome the challenges set. The new firing head will allow the perforating command to be given through an optical signal instantaneously at depth with no disturbance to the well fluid dynamics. This technique will also optimize an online rig operation where displacement, perforation, and nitrogen lift contingency can be performed in one CT run, hence reducing operating costs. Since the initial startup of the two pilot wells, the injection rates of the wells are at optimum, and the performance gained from the two wells has increased overall production in the field. Real-time underbalance perforating is thus seen as the way forward not only to enhance producing wells, but also to boost injectors as well, prolonging the life of an offshore oilfield.
Planning, Execution, Improvements, and Results from a Multi-Well Fishing Campaign using a Snubbing Unit on Pressurized H2S Wells for a NOC in the Middle East
Authors: Donaldson Albert , Al-Mayyan Haitham 
Published: March 2019

Abstract
This paper describes the planning, execution, improvements, and results from a multi-well fishing campaign using a snubbing unit on pressurized H2S wells for a national oil company (NOC) in the Middle East. A suitable blow out preventer (BOP) stack is shown for fishing coiled tubing, wireline tools, and milling along with the contingencies considered and how these were incorporated into the design of the stack. The challenges encountered during the execution phase are explained along with the solutions implemented. The key performance indicators used and how these improved the operational efficiency during the campaign are discussed. The well problems, desired results, and actual results of the interventions on the wells completed to date are shown.
Long Lateral Restriction Diagnosed by Camera-Caliper Combo on E-Line Tractor in One Run
Authors: Lay Allison , Paxson Tanner , Murrill Gary , Schwanitz Brian , Strubberg Brandon 
Published: March 2019

Abstract
An operator in west Texas experienced an obstruction pumping down a plug and perforating gun combination on a multi-stage frac operation in a 23,600-ft lateral. Following a 3.74" OD gauge run with 2-3/8" coiled tubing (CT), which hung up at 18,266 ft, a 3" gauge run was able to pass the holdup depth (HUD). To determine the cause of the restriction, the operator decided to run a video camera and a multi-finger caliper tool. However, due to some concerns with CT reach in the long lateral, issues with friction reducers, undesirable memory timers for recording the logs, and the inability to repeat logging in zones of interest or missing data, the camera provider recommended the logging be performed in "real time" on an electric-line (e-line) tractor.
A shop systems integration test of the combined tractor, caliper and camera was performed prior to running in the well. Clear fluid (fresh water) was pumped down the 5.5" × 4.5" casing from surface to obtain quality video downhole. Upon running the live system with the tractor, several over-torqued collars were identified as well as some buckling above those collars. The images were clear, and the problem areas were successfully identified. The total distance tractored was 10,063 ft, passing through the bad collars to the total measured depth of 23,511 ft.
This was the first time that a downhole video camera was run in combination with a multi-finger caliper tool on an e-line tractor in one run. This service benefits the industry in the following ways: Flexible logging program with real time diagnostics and decisions on additional passes in problem areas.No fluid darkening friction reducers necessary to achieve long lateral total depth.No CT helical buckling concerns.Small foot print for logging program on multi-well pads.Less chance of damaging logging tools on tractor than on CT if obstructions encountered.
This paper describes the operational details of this case and offers insights into the potential uses for such a service to the industry.
Successful Retrieval of Stuck Profile Plug Using Electric-Line Deployed Robotic Well Intervention Techniques
Authors: Vijay Rachit , Panigrahi Nishant , Khanna Manu , Kothiyal Manish Dutt , Sarma P J , Bohra Avinash , Tiwari Shobhit , Pinto Thomas 
Published: March 2019

Abstract
The subject well is a recently drilled and completed in Cambay field offshore in West coast of India. After landing the completion, two mechanical plugs were installed to nipple down BOP and nipple up X-mas tree. The plugs were installed in a 3.875" tubing hanger profile and in a 3.813" SC-TRSSSV selective profile. The problem arose while retrieving the 3.813" selective plug with 4" GS tool after installation of X-mas tree. The slickline wire snapped while doing the jarring operations resulting in fish in the well with BHA and plug slipping down below the selective profile. The plug fell inside the well and got stuck at the 4.5" × 3.5" tubing crossover joint ~20m below the SC-TRSSSV depth. The fished slickline wire along with the slickline tool-string BHA was successfully retrieved from the well, however, the plug remained stuck at the 4.5" × 3.5" tubing cross-over and could not be fished out even after several conventional approaches with slickline.
Solutions involving rig based retrieval and rig less coil tubing intervention and e-line robotic technology for retrieval of the plug were evaluated. Upon completion of a detailed feasibility study of available options, it was decided to conduct fishing of the plug with e-line based advanced robotic well intervention techniques such as eline miller, tractor and stroker. Unique milling bits were designed and customized for this operation. The milling operation involved multiple runs to target the removal of various parts of the struck lock mandrel. Upon successful milling operation, it was planned to retrieve the plug with slickline.
Initial attempts to retrieve the plug by straight pull using 33k pulling capacity Eline Stroker were unsuccessful. Subsequently, milling was attempted with a combination of E-line tractor and Miller to drill thru the plug. The milling initially started as per the plan but after 3 inches of milling the bit got stalled and was eventually stuck inside the plug. The E-line BHA had to be released from the mechanical disconnect sub above the bit. A modified 2" UPT tool with E-line tractor-stroker was run to fish out the bit and plug which resulted in the plug getting released from the stuck position and moving upwards about 10-meter from the stuck depth. Once this was accomplished, plug and bit were successfully retrieved with slickline.
The paper details the background of the stuck incident, selection methodology of fishing technique, fishing work plan and its successful execution. The paper also describes the operational difficulties encountered and the mitigation chosen while milling a plug with an electric line in the offshore environment.
Kinetic Blowout Stopper - The Airbag for the Oil and Gas Industry
Authors: Gallagher Bobby , Juda Dave , Gallagher Billy , Angstmann Steven 
Published: March 2019

Abstract
A proprietary design using a pyro-mechanical, electrically initiated, kinetic energy enabled shearing action has safely and reliably delivered on the promise of "Shear Anything" and seal successfully.
The kinetic blowout stopper (K-BOS) will shear anything in the well above the bit thus eliminating non-shearables from the oil & gas lexicon. Further a superior clean fish with minimal deformation is produced by the kinetic shearing action. The K-BOS will shut-in full flow and pressure blowouts in milliseconds with its simple protected hermetically sealed construction for unparalleled post–shearing sealing performance and dramatically reduce extremely deadly and damaging flammable and/or toxic gas releases. With unrivalled confidence and reliability with best-in-industry control system monitoring and function testing and actuation techniques, the K-BOS requires virtually zero maintenance because of its simple construction where the working components are not wetted by wellbore fluids until actuation, meaning lower costs and reduced NPT and downtime. Like the automotive air bag, the K-BOS is self-contained and meets US and International deregulation requirements regarding safety and logistics of pyrotechnic devices.
Starting with ballistic modeling technology developed for the military, the models were adapted to the K-BOS application and predicted the outcomes of shearing tests with different common tubulars including traditional "unshearables." A testing regime has been conducted to validate the models, demonstrate repeatability of the results, and demonstrate that a post shear seal could be achieved.
More than 30 test serials with the K-BOS 4-1/16″ prototype including empty well-bore tests, shear tests ranging from 5/16″ wireline to 3-1/2″ Drill Collar with a 1″ Wall Thickness. All tests to date have sheared the target tubular without failure. Multiple materials and configurations have been tested.
In all the shearing tests, the K-BOS successfully sheared the target while achieving all safety objectives. The shear test program has validated the models and has also provided validation data allowing for adjustments to the modeling technology for this specific application and resulting in a high level of accuracy and precision in design and shear performance expectations. The shear testing also showed that the K-BOS can shear without damaging the seals and provides an adequate sealing surface after shearing.
The K-BOS has successfully met technical readiness level 5 (API 17N scale) and is ready to move on to in the field scale shear and seal testing. These results and the continuation to continuing development further the prospects of ensuring the K-BOS achieves its mission to strengthen the industry's social license to operate.
Remote Monitoring and Modeling of Coiled Tubing Operations in Real Time
Authors: Brown Paul , Gunby Brian , Torres Carlos , Rao Bharath 
Published: March 2019

Abstract
Service company and operator personnel increasingly wish to monitor coiled tubing (CT) operations from a remote location. Very often the interested party will connect to the data logging computer in the field via an internet connection using freely available commercial software, which allows them to view the computer screen as it appears to the personnel on location. However, streaming video in this manner requires a fast and reliable connection. It also leaves the viewer in a predominantly passive role, with the burden of running the software remaining with the personnel in the CT unit, who must therefore be trained to handle that task along with their other duties.
A different approach, first introduced to the CT industry in 2015, involves streaming the acquired job data to a remote web server in small packets, and reconstructing the complete data file on arrival. The data can then be viewed in near real-time by any authorized person with an internet connection and a browser. The method requires little bandwidth, and works even with an intermittent connection. In a further innovation, the live data is simultaneously fed into tubing forces analysis (TFA) and fatigue modeling software running on the same web server, with the resulting real-time pipe status displayed in the browser alongside the data charts. Adjustments to the models and job design can be made by a person observing the job remotely, rather than on location, with potential for significant cost savings.
At the same time, an algorithm monitors the incoming data stream for detectable events, and triggers automated notifications to personnel who are ‘following’ the job. In this manner an operator can be alerted when, for example, the CT approaches a target of interest; a technician can be warned that a sensor is failing; and an engineer can be alerted if the pipe limits are in danger of being exceeded.
This web-based system has been used extensively over a period of several years, with up to 50 jobs streaming on a typical day. Field examples will be presented illustrating this technology, and contrasted with conventional methods. Limitations as well as advantages will be discussed, in particular concerns about web connectivity at the wellsite, and possible solutions presented.
The case will be made that, by moving the majority of the job monitoring process offsite, the need for specialist expertise in the field is reduced, with associated cost savings. Furthermore, by integrating the entire job process, from planning to completion, into a single web-based platform accessible to any involved party regardless of geographic location, numerous possibilities for other efficiencies can be imagined and realized.
Real-Time Fiber-Optic Integrated System Allows Precision in a Surgical Sand Plug Settlement of a Temporary Well Isolation Operation
Authors: Vera Vanesa , Torres Carlos , Delgado Eduardo , Pacheco Carlos , Torres Monica , Higuera Josue 
Published: March 2019

Abstract
Pumping sand through coiled tubing (CT) with real-time capabilities is not a common practice because of potential risks associated with cable integrity. A successful sand plug settling procedure supported by a real-time fiber-optic integrated system under critical well conditions was of high importance during a recompletion intervention, allowing optimization of time and costs.
Multiple methods are used to isolate a well during recompletion activities; nevertheless, a cost-effective method to divert involves setting sand plugs with CT and a real-time fiber-optic integrated system, which is essential to achieving precise settlement of the sand, not just for depth but also for volume of sand pumped. Without this complete system, the operator would need to make extra runs for correlations with electric line (e-line) or CT units, which increases both cost and operational time.
A real-time fiber-optic integrated system allows adjustment to the sand plug stages in real time to help ensure top of sand (TS) necessary to isolate the producer formation and keep out the wireline entry guide without additional runs and increased costs.
A casing collar locator (CCL) tool permitted the correlation depth to be measured in each tag, ensuring knowledge of where the sand was placed and helping prevent incorrect depths resulting from uncontrollable factors, such as elongation.
More than 6,500 lbm of sand was pumped through CT using a real-time fiber-optic integrated system without losing communication with the downhole tools and without affecting cable integrity, which could lead to bird nesting the cable because of high friction and excessive slack inside the pipe.
This real-time fiber-optic integrated system begins a new generation of sand plug operations by helping prevent additional runs or having other units correlate, particularly if a recompletion activity is programmed and space accommodation is a challenge because of the workover unit.
A Precision Drilling Tool – A New Approach to Open for Production by Using a Novel Method to Drill Holes Through Base Pipe in Sand Screen or through Tubing/Casing
Authors: Magnussen Espen Johan , Haugen Vidar , Sarbaz Saman , Karlsen Ole Edvind , Nordaas Lars Bjarne , Holst Tor Kristian 
Published: March 2019

Abstract
The use of an electric drilling tool deployed on wireline is shown to be a safe, efficient and reliable method to penetrate the base pipe in sand screens.
In the case study presented in this paper, a well on a field on the Norwegian Continental Shelf, completed with a Darcy sand screen that was clogged due to scale. A Darcy screen is an expandable hydraulically activated sand screen. An electric drill deployed on wireline was used to drill holes through the base pipe of the screen and into the flow channels to open for production. The tool needed a sufficient anchoring capacity for keeping the drill bit steady as well as accuracy of the drilling process to prevent damaging the underlying filter media. Both the anchor and the drill section of the drilling tool deployed are shown to be designed to meet these specifications. The sequence of the operation is presented, where two circular patterns at different depths with 13 holes each are drilled. At the time of publishing for this paper, the results on production from this operation is not yet known, as the well has not started producing again.
Wirelessly Powered Microchips for Mapping Hydraulic Fractures
Authors: Cherivirala Y. K. , Lyu H.. , Alhowri H. A. , Babakhani A.. 
Published: March 2019

Summary
The onset of the era of internet of things and artificial intelligence comes with the ever-growing demand for self-sustaining and efficient sensors. Sensors based on complementary metal oxide semiconductors (CMOSs) have attracted significant attention in the implementation of distributed sensor systems for a vast number of applications because of their economical and complex integration benefits. In this work, we report CMOS-based energy-harvesting chips as wireless nodes for mapping hydraulic fractures during the shale gas extraction process. The CMOS chips are tested in a custom benchtop core-holder chamber that emulates a downhole environment. An induction coil, sized at 5 × 5 mm, connected to a custom CMOS chip, is used as a receiver inside the core holder to harvest electromagnetic (EM) energy transmitted by an external antenna. On the basis of the custom core-holder experiment, it is shown that encapsulated CMOS chips are able to harvest EM energy and thereby operate wirelessly. The receiver has a resonance frequency of 198 MHz. The CMOS chip is equipped with an integrated power management unit (PMU), energy-harvesting unit, and a signal-generation block. The CMOS chip inside the chamber produces an output signal with a frequency proportional to the harvested power. By measuring the frequency of the output signal produced by the chip, we are able to localize the chips within the rock inside the custom core holder.
The role of PKCγ subunit of rACC neurons in the development of bone cancer pain in rats
Authors: Feng Hao , Feng Zequn , She Meng , Wang Gongming , Cheng Guanghui , Li Kailin , Wang Ruoyi , Li Xiaohui 
Published: March 2019

Abstract
Background：To explore the role of PKCγ subunit of rACC neurons in the development of bone cancer pain in rats. Methods：40 adult female SD rats were divided into five groups: blank control group (Naive group), sham operation group (Sham group), bone cancer pain group (BCP group)，empty lentiviral vector group（Vehicle group） and PKCγ/shRNA recombinant lentiviral vector group (PKCγ group). 10μl MADB-106 rat mammary cancer cells suspension was inoculated into the tibia bone marrow cavity of rats in BCP group and Vehicle group similarly. 10μl saline was inoculated into the proximal tibia bone marrow cavity of rats in Sham group. In the PKCγ group, the rats were taken the same treatment as the BCP group, and then 10μl shRNA/PKCγ recombinant lentivirus was injected into the bilateral rACC on the 7th day. The mechanical withdrawal threshold and thermal withdrawal latency were measured every 3 days to assess the rat pain behavior. Immunohistochemistry, Western blotting technology and immunofluorescence were used to detect the expression of PKCγ subunits in rat rACC neurons after operation. Results: From the 3rd day after operation, the mechanical withdrawal thresholds in BCP group, Vehicle group and PKCγ group were significantly decreased than those in Naive group and Sham group (P<0.05). Compared with the BCP group and Vehicle group the mechanical withdrawal threshold in the PKCγ group increased significantly (P<0.05). On the 3rd postoperative day, the thermal withdrawal latency in BCP, Vehicle and PKCγ groups was significantly longer than those in Naive and Sham groups（P＜0.05). From the 14th postoperative day, the TWL in PKCγ group was shorter than that in BCP and Vehicle groups (P<0.05). Western blot analysis showed that the expression of PKCγ in rACC neurons on the 14th day after operation in rats of BCP and Vehicle groups were significantly higher than that in Naive group and Sham group. (P<0.05) However, in the PKCγ group, the expression of PKCγ in rACC neurons was significantly lower than that in BCP group (P<0.05). Conclusion: Up-regulation of PKC subunit of rACC neurons in bone cancer pain rats contributes to the development of pain sensitivity in bone cancer.