ACTIVE CONTROL FOR THE RE-ENTRY OPERATION OF FLEXIBLE RISERS
Authors: Eugenio Fortaleza, Yann Creff, Jean Lévine, MATHMOD 09, pp. 973-979, February 11 - 13, 2009, Vienna, Austria
This paper presents an active control dedicated to a re-entry problem found in the offshore oil industry. The re-entry operation consists in connecting the bottom of a very long pipeline to the wellhead, by dynamically modifying the pipeline top position, which is linked to a floating device (vessel or platform). These long pipelines are usually called risers, because they are used to rise the drilling mud or the hydrocarbons from the wellhead to the platform. Nowadays the re-entry operation is done manually. The use of an active control intends to reduce the operation time, and to make it possible even under bad weather conditions. The considered offshore structure can be analyzed as a cable submerged in a flow. A convenient model is given by the Bernoulli’s historical cable equation, completed with a damping factor, that linearly depends on the structure speed. The damping factor is developed in series around zero, to get an approximate solution. The corresponding model turns out to be differentially flat[1], a property directly used in the control design, providing an extension to previous works of Petit and Rouchon [2], Thull et al [3], and Sabri [4]. This paper presents an overview of the results of [5]. Furthermore it contains material concerning a new tracking system, that uses the system inversion to define the feedback control.
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BibTeX:
@Proceedings{,
author = {Eugenio Fortaleza, Yann Creff, Jean Lévine},
editor = {},
title = {ACTIVE CONTROL FOR THE RE-ENTRY OPERATION OF FLEXIBLE RISERS},
booktitle = {MATHMOD 09},
volume = {},
publisher = {},
address = {Vienna},
pages = {973-979},
year = {2009},
abstract = {This paper presents an active control dedicated to a re-entry problem found in the offshore oil industry. The re-entry operation consists in connecting the bottom of a very long pipeline to the wellhead, by dynamically modifying the pipeline top position, which is linked to a floating device (vessel or platform). These long pipelines are usually called risers, because they are used to rise the drilling mud or the hydrocarbons from the wellhead to the platform. Nowadays the re-entry operation is done manually. The use of an active control intends to reduce the operation time, and to make it possible even under bad weather conditions. The considered offshore structure can be analyzed as a cable submerged in a flow. A convenient model is given by the Bernoulli’s historical cable equation, completed with a damping factor, that linearly depends on the structure speed. The damping factor is developed in series around zero, to get an approximate solution. The corresponding model turns out to be differentially flat[1], a property directly used in the control design, providing an extension to previous works of Petit and Rouchon [2], Thull et al [3], and Sabri [4]. This paper presents an overview of the results of [5]. Furthermore it contains material concerning a new tracking system, that uses the system inversion to define the feedback control.},
keywords = {}}
This paper presents an active control dedicated to a re-entry problem found in the offshore oil industry. The re-entry operation consists in connecting the bottom of a very long pipeline to the wellhead, by dynamically modifying the pipeline top position, which is linked to a floating device (vessel or platform). These long pipelines are usually called risers, because they are used to rise the drilling mud or the hydrocarbons from the wellhead to the platform. Nowadays the re-entry operation is done manually. The use of an active control intends to reduce the operation time, and to make it possible even under bad weather conditions. The considered offshore structure can be analyzed as a cable submerged in a flow. A convenient model is given by the Bernoulli’s historical cable equation, completed with a damping factor, that linearly depends on the structure speed. The damping factor is developed in series around zero, to get an approximate solution. The corresponding model turns out to be differentially flat[1], a property directly used in the control design, providing an extension to previous works of Petit and Rouchon [2], Thull et al [3], and Sabri [4]. This paper presents an overview of the results of [5]. Furthermore it contains material concerning a new tracking system, that uses the system inversion to define the feedback control.
Download PDF
BibTeX:
@Proceedings{,
author = {Eugenio Fortaleza, Yann Creff, Jean Lévine},
editor = {},
title = {ACTIVE CONTROL FOR THE RE-ENTRY OPERATION OF FLEXIBLE RISERS},
booktitle = {MATHMOD 09},
volume = {},
publisher = {},
address = {Vienna},
pages = {973-979},
year = {2009},
abstract = {This paper presents an active control dedicated to a re-entry problem found in the offshore oil industry. The re-entry operation consists in connecting the bottom of a very long pipeline to the wellhead, by dynamically modifying the pipeline top position, which is linked to a floating device (vessel or platform). These long pipelines are usually called risers, because they are used to rise the drilling mud or the hydrocarbons from the wellhead to the platform. Nowadays the re-entry operation is done manually. The use of an active control intends to reduce the operation time, and to make it possible even under bad weather conditions. The considered offshore structure can be analyzed as a cable submerged in a flow. A convenient model is given by the Bernoulli’s historical cable equation, completed with a damping factor, that linearly depends on the structure speed. The damping factor is developed in series around zero, to get an approximate solution. The corresponding model turns out to be differentially flat[1], a property directly used in the control design, providing an extension to previous works of Petit and Rouchon [2], Thull et al [3], and Sabri [4]. This paper presents an overview of the results of [5]. Furthermore it contains material concerning a new tracking system, that uses the system inversion to define the feedback control.},
keywords = {}}