Search
Filters

10402 THPS Degradation in the Long-term Preservation of Subsea Flowlines and Risers

The Thunder Horse project’s sub-sea flow-lines were installed in 6,000’ water depths and filled with chemically treated seawater. After 2 years, investigations were done to determine continued effectiveness of the chemical treatments. 

Product Number: 51300-10402-SG
ISBN: 10402 2010 CP
Author: Jeffrey Willmon
Publication Date: 2010
$0.00
$20.00
$20.00

The Thunder Horse project’s sub-sea flow-lines were installed in 6,000’ water depths; the installation of the risers followed a year later. These lines were initially filled with chemically treated seawater in anticipation of hydro-testing and start-up. The initial chemical treatments were in accordance with BP guidelines and EPA GoM specific regulations. The initial chemical treatments consisted of a THPS biocide (~270 ppm), oxygen scavenger (~100 ppm), corrosion inhibitor (~100 ppm), and dye (~30 ppm). The initial chemically-treated fluids remained in place for up to two years during which time installation operations continued. Due to the extended length of fluid residence time, investigations were undertaken to determine the continued effectiveness of the chemical treatments in maintaining the mechanical integrity of the risers and flow-lines. The primary interest of this investigation was to determine the degradation rate of the active biocide product, THPS, under in-situ conditions. With an understanding of the biocide degradation rate, the Project Team could effectively and efficiently maintain the appropriate concentrations of biocide in the fill fluids for the control of microbial influenced corrosion. This paper summarizes the work done by the Thunder Horse Sub-sea Commissioning Team to investigate THPS degradation of chemically treated seawater in sub-sea risers and flow-lines. The investigation included the following. 1. Literature review of associated THPS degradation data, 2. Laboratory study to investigate the degradation of THPS in the sub-sea risers and flow-lines, and 3. A sampling campaign during the execution of the Thunder Horse project’s installation and commissioning scopes of work to quantify the actual THPS initial and final concentrations. Key Words: Hydrotest, THPS, MIC

The Thunder Horse project’s sub-sea flow-lines were installed in 6,000’ water depths; the installation of the risers followed a year later. These lines were initially filled with chemically treated seawater in anticipation of hydro-testing and start-up. The initial chemical treatments were in accordance with BP guidelines and EPA GoM specific regulations. The initial chemical treatments consisted of a THPS biocide (~270 ppm), oxygen scavenger (~100 ppm), corrosion inhibitor (~100 ppm), and dye (~30 ppm). The initial chemically-treated fluids remained in place for up to two years during which time installation operations continued. Due to the extended length of fluid residence time, investigations were undertaken to determine the continued effectiveness of the chemical treatments in maintaining the mechanical integrity of the risers and flow-lines. The primary interest of this investigation was to determine the degradation rate of the active biocide product, THPS, under in-situ conditions. With an understanding of the biocide degradation rate, the Project Team could effectively and efficiently maintain the appropriate concentrations of biocide in the fill fluids for the control of microbial influenced corrosion. This paper summarizes the work done by the Thunder Horse Sub-sea Commissioning Team to investigate THPS degradation of chemically treated seawater in sub-sea risers and flow-lines. The investigation included the following. 1. Literature review of associated THPS degradation data, 2. Laboratory study to investigate the degradation of THPS in the sub-sea risers and flow-lines, and 3. A sampling campaign during the execution of the Thunder Horse project’s installation and commissioning scopes of work to quantify the actual THPS initial and final concentrations. Key Words: Hydrotest, THPS, MIC

Product tags
Also Purchased
Picture for 03572 CHEMICAL TREATMENT OPTIONS FOR HYDROTEST
Available for download

03572 CHEMICAL TREATMENT OPTIONS FOR HYDROTEST

Product Number: 51300-03572-SG
ISBN: 03572 2003 CP
Publication Date: 2003
$20.00
Picture for 10406 Laboratory Investigation of MIC in Hydrotest Using Seawater
Available for download

10406 Laboratory Investigation of MIC in Hydrotest Using Seawater

Product Number: 51300-10406-SG
ISBN: 10406 2010 CP
Author: Kaili Zhao, Tingyue Gu, Czar Ivan T. Cruz and Ardjan Kopliku
Publication Date: 2010
$20.00
Picture for 10403 Subsea SCR/Flowline Preservation-Maintenance of Fill Fluids During Thunder Horse Subsea Kit
Available for download

10403 Subsea SCR/Flowline Preservation-Maintenance of Fill Fluids During the Thunder Horse Subsea Kit Re-installation Campaign

Product Number: 51300-10403-SG
ISBN: 10403 2010 CP
Author: Jeffrey Willmon
Publication Date: 2010
$20.00