Direct Electrical Heating of Subsea Pipelines—Technology Development and Operating Experience

Nysveen, Arne; Kulbotten, Harald; Lervik, Jens Kristian; Børnes, Atle Harald; Høyer-Hansen, Martin; Bremnes, Jarle J.

doi:10.1109/tia.2006.886425

“…Industry partners have used DEH at selected fields since 2000, and the method has proved very good under various operating conditions. So far, the method is used up to 1 km water depth and approximately 45 km pipeline length (Nysveen et al, 2005). DEH system is, effective and efficient over short distances and it is environmentally friendly than chemical inhibition.…”

Section: Temperature Losses Control Mechanismsmentioning

confidence: 99%

Flow Assurance in Subsea Pipeline Design - A Case Study of Ghana’s Jubilee and TEN Fields

Marfo¹,

Appau²,

Acquah³

et al. 2019

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The increasing exploration and production activities in the offshore Cape Three Point Blocks of Ghana have led to the discovery and development of gas condensate fields in addition to the oil fields which produce significant amount of condensate gas. These discoveries require pipelines to transport the fluids avoiding hydrates and wax formation. This paper focuses on subsea pipeline design using Pipesim software that addresses flow assurance problems associated with transporting condensate gas from the Jubilee and TEN Fields to the Atuabo Gas Processing Plant. It also considered an alternate design that eliminates the need for capacity increase of flowlines for the futuristic highest projected flow rates in 2030. The design comprises of two risers and two flowlines. Hydrate formation temperature was determined to be 72.5 ˚F at a pressure of 3 000 psig. The insulation thickness for flowlines 1 and 2 were determined to be 1.5 in. and 2 in. respectively. The pipe size for flowlines 1 and 2 were determined to be 12 in. and 14 in. respectively. The maximum designed flow rate was determined to be 150 MMSCFD. To meet the highest projected flow rate of 700 MMSCFD in the year 2030 at the processing plant, a 16 in. ID pipeline of 44 km length was placed parallel to the 12 in. ID flowline 1. This parallel pipeline increased the designed flow rate by approximately 4.7 times (705 MMSCFD). The alternate design employs 18 in. and 20 in. ID pipes for flowlines 1 and 2 respectively. Keywords: Condensate Gas; Flowline; Flow Assurance; Hydrate; Pipesim

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“…A typical direct electric heating system, shown in Fig. 1, utilizes a line-frequency 3-phase source in conjunction with a transformer and a load balancing network to circulate a single-phase alternating current through the metallic wall of the subsea pipeline [1], [2]. The resulting I 2 R loss maintains the pipeline flow at the required operating temperature.…”

Section: Introductionmentioning

confidence: 99%

Design and Evaluation of a High Current Gain Resonant Inverter for Subsea Electrical Heating

Ray¹,

Kaushik²

2021

Preprint

0

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Direct electrical heating (DEH) is a well-established method for preventing hydrate formation inside subsea oil transfer pipelines. However, poor efficiency and high reactive power requirement of the existing line-frequency DEH systems have necessitated high-frequency power processing along with reactive power compensation. To meet these design objectives, a dc-ac converter using an LCCL resonant tank is presented in this paper to function as a high-frequency alternating current source. The LCCL resonant tank is tuned at the frequency of the peak tank current gain to maximize the heat generation and reduce the VA rating of the tank. The peak current gain operation also ensures zero voltage switching (ZVS) of the bridge inverter devices. Detailed frequency domain analysis and design guidelines are presented for the proposed LCCL resonant inverter (RI). Experimental results on a 10 A laboratory prototype and hardware-in-the-loop results for a 350 A system illustrate the advantages of the LCCL RI in DEH application.

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“…DEH is a relatively new technology in the subsea O&G industry, with the first DEH system implemented at the Asgard , [2] field in Norway in the year 2000 [4]. Over the next two decades, two types of DEH technology have been explored, namely, DEH for wet insulated pipeline (DEH-WIP) and DEH for pipe-in-pipe (DEH-PIP).…”

Section: Introductionmentioning

confidence: 99%

Design and Evaluation of a High Current Gain Resonant Inverter for Subsea Electrical Heating

Ray¹,

Kaushik²

2021

Preprint

0

View full text Add to dashboard Cite

Direct electrical heating (DEH) is a well-established method for preventing hydrate formation inside subsea oil transfer pipelines. However, poor efficiency and high reactive power requirement of the existing line-frequency DEH systems have necessitated high-frequency power processing along with reactive power compensation. To meet these design objectives, a dc-ac converter using an LCCL resonant tank is presented in this paper to function as a high-frequency alternating current source. The LCCL resonant tank is tuned at the frequency of the peak tank current gain to maximize the heat generation and reduce the VA rating of the tank. The peak current gain operation also ensures zero voltage switching (ZVS) of the bridge inverter devices. Detailed frequency domain analysis and design guidelines are presented for the proposed LCCL resonant inverter (RI). Experimental results on a 10 A laboratory prototype and hardware-in-the-loop results for a 350 A system illustrate the advantages of the LCCL RI in DEH application.

show abstract

Direct Electrical Heating of Subsea Pipelines—Technology Development and Operating Experience

Cited by 37 publications

References 4 publications

Flow Assurance in Subsea Pipeline Design - A Case Study of Ghana’s Jubilee and TEN Fields

Flow Assurance in Subsea Pipeline Design - A Case Study of Ghana’s Jubilee and TEN Fields

Design and Evaluation of a High Current Gain Resonant Inverter for Subsea Electrical Heating

Design and Evaluation of a High Current Gain Resonant Inverter for Subsea Electrical Heating

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