Detection of NPT and Drilling Events on the NCS from Depth-based Drilling Mechanics
Drilling events are subsurface related events that result in non-productive time (NPT) and increased costs. The aim of this thesis was to improve the understanding of drilling events to help mitigate non-productive time in drilling operations. NPT and drilling events related to drilling operations w...
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ftunivstavanger:oai:uis.brage.unit.no:11250/2786344 2023-06-11T04:15:27+02:00 Detection of NPT and Drilling Events on the NCS from Depth-based Drilling Mechanics Blikra, Håvard. Yahya, Mohammad. Lekens, Wim. 2021 application/pdf https://hdl.handle.net/11250/2786344 eng eng uis no.uis:inspera:78874059:22337515 https://hdl.handle.net/11250/2786344 Master thesis 2021 ftunivstavanger 2023-05-29T16:01:57Z Drilling events are subsurface related events that result in non-productive time (NPT) and increased costs. The aim of this thesis was to improve the understanding of drilling events to help mitigate non-productive time in drilling operations. NPT and drilling events related to drilling operations was studied and a consistent data analytics workflow in MATLAB was developed. An initial case study was conducted, and a prototype MATLAB workflow developed, testing different approaches for drilling events detection. Based on the result from the initial case study from the Northern North Sea, the workflow was updated and 20 wells from the North Sea and Norwegian Sea were analysed. Mechanical specific energy and drilling strength models were calculated from depth-based drilling mechanics, and combined with the ratio between the two, the MSE/DS ratio, a workflow was created to detect drilling events. Based on cut-off values from the initial case study, the developed workflow enabled the detection of bit balling, vibrations, and bit wear. Unconfined compressive strength (UCS) was estimated from Sonic data and lithology, enabling the detection of hard rock. Two methods were developed to estimate lost drilling time due to drilling events: The WOB-method and the Torque-method. Utilizing the linear relationship between ROP-WOB and Torque-WOB for efficient drilling, efficient bit-lines were created, enabling the estimation of lost drilling time due to inefficient drilling. By comparing bit changes to detected drilling events, lost time due to unplanned tripping was estimated. The result from the initial case study showed a strong match between the reported events and the developed workflow. Among the 20 analysed wells, vibrations were the most common detected drilling event, with an average 41 m/km detected pr well. The largest contributor to NPT was bit balling, contributing to 44% of the lost time. On average, 69 hours were lost due to drilling events, equivalent to 5% of the total time for the drilling operations, with an ... Master Thesis Norwegian Sea University of Stavanger: UiS Brage Norwegian Sea |
institution |
Open Polar |
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University of Stavanger: UiS Brage |
op_collection_id |
ftunivstavanger |
language |
English |
description |
Drilling events are subsurface related events that result in non-productive time (NPT) and increased costs. The aim of this thesis was to improve the understanding of drilling events to help mitigate non-productive time in drilling operations. NPT and drilling events related to drilling operations was studied and a consistent data analytics workflow in MATLAB was developed. An initial case study was conducted, and a prototype MATLAB workflow developed, testing different approaches for drilling events detection. Based on the result from the initial case study from the Northern North Sea, the workflow was updated and 20 wells from the North Sea and Norwegian Sea were analysed. Mechanical specific energy and drilling strength models were calculated from depth-based drilling mechanics, and combined with the ratio between the two, the MSE/DS ratio, a workflow was created to detect drilling events. Based on cut-off values from the initial case study, the developed workflow enabled the detection of bit balling, vibrations, and bit wear. Unconfined compressive strength (UCS) was estimated from Sonic data and lithology, enabling the detection of hard rock. Two methods were developed to estimate lost drilling time due to drilling events: The WOB-method and the Torque-method. Utilizing the linear relationship between ROP-WOB and Torque-WOB for efficient drilling, efficient bit-lines were created, enabling the estimation of lost drilling time due to inefficient drilling. By comparing bit changes to detected drilling events, lost time due to unplanned tripping was estimated. The result from the initial case study showed a strong match between the reported events and the developed workflow. Among the 20 analysed wells, vibrations were the most common detected drilling event, with an average 41 m/km detected pr well. The largest contributor to NPT was bit balling, contributing to 44% of the lost time. On average, 69 hours were lost due to drilling events, equivalent to 5% of the total time for the drilling operations, with an ... |
author2 |
Yahya, Mohammad. Lekens, Wim. |
format |
Master Thesis |
author |
Blikra, Håvard. |
spellingShingle |
Blikra, Håvard. Detection of NPT and Drilling Events on the NCS from Depth-based Drilling Mechanics |
author_facet |
Blikra, Håvard. |
author_sort |
Blikra, Håvard. |
title |
Detection of NPT and Drilling Events on the NCS from Depth-based Drilling Mechanics |
title_short |
Detection of NPT and Drilling Events on the NCS from Depth-based Drilling Mechanics |
title_full |
Detection of NPT and Drilling Events on the NCS from Depth-based Drilling Mechanics |
title_fullStr |
Detection of NPT and Drilling Events on the NCS from Depth-based Drilling Mechanics |
title_full_unstemmed |
Detection of NPT and Drilling Events on the NCS from Depth-based Drilling Mechanics |
title_sort |
detection of npt and drilling events on the ncs from depth-based drilling mechanics |
publisher |
uis |
publishDate |
2021 |
url |
https://hdl.handle.net/11250/2786344 |
geographic |
Norwegian Sea |
geographic_facet |
Norwegian Sea |
genre |
Norwegian Sea |
genre_facet |
Norwegian Sea |
op_relation |
no.uis:inspera:78874059:22337515 https://hdl.handle.net/11250/2786344 |
_version_ |
1768372288561872896 |