Synthesis of No-Wait Cyclic Schedules for Cascade-Like Systems of Repetitive Processes with Fixed Periods

Author(s):  
Robert Wójcik ◽  
Grzegorz Bocewicz ◽  
Zbigniew Banaszak
Keyword(s):  
Author(s):  
H., A. Sinaga

As the new operator of the Mahakam Block started in 2017, Pertamina Hulu Mahakam (PHM) were challenged to ramp up operations in order to combat massive production decline. At the same time, reducing well cost was also a paramount importance to ensure that the economic targets of the wells were achieved following the reduction of well stakes. One of the remaining unsolved enigmas is how to achieve No Wait-on-Cement (NO WOC) on surface diverter section as this will create a lot of rig time saving both on single well and batch operations. The project begins with several different kinds of proposal until the best solutions were identified fulfilling safety, simplicity of operations and acceptable cost and finally were put in place with very satisfying results. The main key principle is conversion wellhead stages following well architecture while there were several modifications of casing hanger, adapter, additional materials & modified procedure. Rig time saving, additional operational gain and a promising new “breakthrough” of drilling technique become a significant impact of the successful effort. Now the method has become a standard in PHM operations and has already been integrated to SDI (Standard Drilling Instruction). The merit of this endless hard work could possibly be gained by other operators as it will create more added values both tangible and intangible.


Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 125
Author(s):  
Kai Huang ◽  
Xinming Wan ◽  
Ke Wang ◽  
Xiaowen Jiang ◽  
Junjian Chen ◽  
...  

With the development of industrial networks, the demands for strict timing requirements and high reliability in transmission become more essential, which promote the establishment of a Time-Sensitive Network (TSN). TSN is a set of standards with the intention of extending Ethernet for safety-critical and real-time applications. In general, frame replication is used to achieve fault-tolerance, while the increased load has a negative effect on the schedule synthesis phase. It is necessary to consider schedulability and reliability jointly. In this paper, a heuristic-based routing method is proposed to achieve fault tolerance by spatial redundancy for TSNs containing unreliable links. A cost function is presented to evaluate each routing set, and a heuristic algorithm is applied to find the solution with higher schedulability. Compared to the shortest path routing, our method can improve the reliability and the success rate of no-wait scheduling by 5–15% depending on the scale of topology.


2020 ◽  
Vol 53 (2) ◽  
pp. 1462-1467
Author(s):  
Robert Maniarski ◽  
Wojciech Paszke ◽  
Eric Rogers ◽  
Marcin Boski

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