Experimental Study on the Effect of Combination of Thermodynamic Inhibitors’ and Kinetic Inhibitors’ Hydrate Inhibition

In deepwater gas well testing, the high-pressure and low-temperature environment in the wellbore provides conditions for hydrate formation. When the thermodynamic inhibitor is used, it needs a large amount and is difficult to inject. Low-dose hydrate inhibitors such as kinetic inhibitors are rarely...

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Main Authors: Yonghai Gao, Yanlong Wang, Guizhen Xin, Xiangdong Wang, Cheng Yue, Litao Chen
Format: Article
Language:English
Published: Frontiers Media S.A. 2021-08-01
Series:Frontiers in Energy Research
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fenrg.2021.718673/full
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author Yonghai Gao
Yanlong Wang
Guizhen Xin
Guizhen Xin
Xiangdong Wang
Cheng Yue
Cheng Yue
Litao Chen
author_facet Yonghai Gao
Yanlong Wang
Guizhen Xin
Guizhen Xin
Xiangdong Wang
Cheng Yue
Cheng Yue
Litao Chen
author_sort Yonghai Gao
collection DOAJ
description In deepwater gas well testing, the high-pressure and low-temperature environment in the wellbore provides conditions for hydrate formation. When the thermodynamic inhibitor is used, it needs a large amount and is difficult to inject. Low-dose hydrate inhibitors such as kinetic inhibitors are rarely used in high supercooling and natural gas–dominated environments. The mixed use of thermodynamic inhibitors and kinetic inhibitors provides a new way. By simulating the wellbore temperature and pressure conditions during the deepwater gas well testing, the inhibiting effect of the mixtures of PVCap and methanol with various concentrations was experimentally tested by using rocking cells with a step-cooling method at 21MPa. The effect of PVCap and its mixture with methanol on hydrate plugging was evaluated by monitoring the movement of slider in the rocking cell. The results showed that 5 wt%, 16 wt%, and 20 wt% methanol mixed with 0.5 wt% PVCap could prolong the induction time, and the higher the methanol concentration, the longer the hydrate induction time. Among them, the best combination of 20wt% methanol and 0.5wt% PVCap can inhibit the hydrate for 379 min. The hydrate was formed but did not block the rocking cell, indicating that the combination of PVCap and methanol could not only prolong the hydrate formation time but also avoid the blockage after hydrate formation. The hydrate formation rate with various inhibitor concentrations was calculated; it may provide some guidance for making a shut-in plan for on-site wells.
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spelling doaj.art-60e0af4537a646469d07a73533e41a6f2022-12-21T22:54:53ZengFrontiers Media S.A.Frontiers in Energy Research2296-598X2021-08-01910.3389/fenrg.2021.718673718673Experimental Study on the Effect of Combination of Thermodynamic Inhibitors’ and Kinetic Inhibitors’ Hydrate InhibitionYonghai Gao0Yanlong Wang1Guizhen Xin2Guizhen Xin3Xiangdong Wang4Cheng Yue5Cheng Yue6Litao Chen7School of Petroleum Engineering, China University of Petroleum (East China), Qingdao, ChinaSchool of Petroleum Engineering, China University of Petroleum (East China), Qingdao, ChinaSchool of Petroleum Engineering, China University of Petroleum (East China), Qingdao, ChinaQingdao Marine Engineering and Subsea Equipment Inspection and Testing Co.Ltd, Qingdao, ChinaOffshore Oil Production Company, Shengli Oilfield, SINOPEC, Dongying, ChinaSchool of Petroleum Engineering, China University of Petroleum (East China), Qingdao, ChinaChina Oilfield Services Limited, Tianjin, ChinaSchool of Petroleum Engineering, China University of Petroleum (East China), Qingdao, ChinaIn deepwater gas well testing, the high-pressure and low-temperature environment in the wellbore provides conditions for hydrate formation. When the thermodynamic inhibitor is used, it needs a large amount and is difficult to inject. Low-dose hydrate inhibitors such as kinetic inhibitors are rarely used in high supercooling and natural gas–dominated environments. The mixed use of thermodynamic inhibitors and kinetic inhibitors provides a new way. By simulating the wellbore temperature and pressure conditions during the deepwater gas well testing, the inhibiting effect of the mixtures of PVCap and methanol with various concentrations was experimentally tested by using rocking cells with a step-cooling method at 21MPa. The effect of PVCap and its mixture with methanol on hydrate plugging was evaluated by monitoring the movement of slider in the rocking cell. The results showed that 5 wt%, 16 wt%, and 20 wt% methanol mixed with 0.5 wt% PVCap could prolong the induction time, and the higher the methanol concentration, the longer the hydrate induction time. Among them, the best combination of 20wt% methanol and 0.5wt% PVCap can inhibit the hydrate for 379 min. The hydrate was formed but did not block the rocking cell, indicating that the combination of PVCap and methanol could not only prolong the hydrate formation time but also avoid the blockage after hydrate formation. The hydrate formation rate with various inhibitor concentrations was calculated; it may provide some guidance for making a shut-in plan for on-site wells.https://www.frontiersin.org/articles/10.3389/fenrg.2021.718673/fullgas well testingPVCapmethanolhydrate formationinhibiting
spellingShingle Yonghai Gao
Yanlong Wang
Guizhen Xin
Guizhen Xin
Xiangdong Wang
Cheng Yue
Cheng Yue
Litao Chen
Experimental Study on the Effect of Combination of Thermodynamic Inhibitors’ and Kinetic Inhibitors’ Hydrate Inhibition
Frontiers in Energy Research
gas well testing
PVCap
methanol
hydrate formation
inhibiting
title Experimental Study on the Effect of Combination of Thermodynamic Inhibitors’ and Kinetic Inhibitors’ Hydrate Inhibition
title_full Experimental Study on the Effect of Combination of Thermodynamic Inhibitors’ and Kinetic Inhibitors’ Hydrate Inhibition
title_fullStr Experimental Study on the Effect of Combination of Thermodynamic Inhibitors’ and Kinetic Inhibitors’ Hydrate Inhibition
title_full_unstemmed Experimental Study on the Effect of Combination of Thermodynamic Inhibitors’ and Kinetic Inhibitors’ Hydrate Inhibition
title_short Experimental Study on the Effect of Combination of Thermodynamic Inhibitors’ and Kinetic Inhibitors’ Hydrate Inhibition
title_sort experimental study on the effect of combination of thermodynamic inhibitors and kinetic inhibitors hydrate inhibition
topic gas well testing
PVCap
methanol
hydrate formation
inhibiting
url https://www.frontiersin.org/articles/10.3389/fenrg.2021.718673/full
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