Effects of Formation Dip on Gas Production from Unconfined Marine Hydrate-Bearing Sediments through Depressurization

The effects of geologic conditions and production methods on gas production from hydrate-bearing sediments (HBS) have been widely investigated. The reservoir was usually treated as horizontal distribution, whereas the sloping reservoir was not considered. In fact, most strata have gradients because...

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Main Authors: Yilong Yuan, Tianfu Xu, Yingli Xia, Xin Xin
Format: Article
Language:English
Published: Wiley 2018-01-01
Series:Geofluids
Online Access:http://dx.doi.org/10.1155/2018/5836293
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author Yilong Yuan
Tianfu Xu
Yingli Xia
Xin Xin
author_facet Yilong Yuan
Tianfu Xu
Yingli Xia
Xin Xin
author_sort Yilong Yuan
collection DOAJ
description The effects of geologic conditions and production methods on gas production from hydrate-bearing sediments (HBS) have been widely investigated. The reservoir was usually treated as horizontal distribution, whereas the sloping reservoir was not considered. In fact, most strata have gradients because of the effects of geological structure and diagenesis. In this study, based on currently available geological data from field measurements in Shenhu area of the South China Sea, the effects of formation dip on gas production were investigated through depressurization using a horizontal well. The modeling results indicate that the strategy of horizontal well is an effective production method from the unconfined Class 2 HBS. The predicted cumulative volume of methane produced at the 1000 m horizontal well was 4.51 × 107 ST m3 over 5-year period. The hydrate dissociation behavior of sloping formation is sensitive to changes in the reservoir pressure. As in unconfined marine hydrate reservoir, the sloping formation is not conducive to free methane gas recovery, which results in more dissolved methane produced at the horizontal well. The obvious issue for this challenging target is relatively low exploitation efficiency of methane because of the recovery of very large volumes of water. Consequently, the development of the favorable well completion method to prevent water production is significantly important for realizing large scale hydrate exploitation in the future.
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spelling doaj-art-74dcb615df4b4276b0657a547ff8f1d42025-08-20T02:07:27ZengWileyGeofluids1468-81151468-81232018-01-01201810.1155/2018/58362935836293Effects of Formation Dip on Gas Production from Unconfined Marine Hydrate-Bearing Sediments through DepressurizationYilong Yuan0Tianfu Xu1Yingli Xia2Xin Xin3Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, ChinaKey Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, ChinaKey Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, ChinaKey Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, ChinaThe effects of geologic conditions and production methods on gas production from hydrate-bearing sediments (HBS) have been widely investigated. The reservoir was usually treated as horizontal distribution, whereas the sloping reservoir was not considered. In fact, most strata have gradients because of the effects of geological structure and diagenesis. In this study, based on currently available geological data from field measurements in Shenhu area of the South China Sea, the effects of formation dip on gas production were investigated through depressurization using a horizontal well. The modeling results indicate that the strategy of horizontal well is an effective production method from the unconfined Class 2 HBS. The predicted cumulative volume of methane produced at the 1000 m horizontal well was 4.51 × 107 ST m3 over 5-year period. The hydrate dissociation behavior of sloping formation is sensitive to changes in the reservoir pressure. As in unconfined marine hydrate reservoir, the sloping formation is not conducive to free methane gas recovery, which results in more dissolved methane produced at the horizontal well. The obvious issue for this challenging target is relatively low exploitation efficiency of methane because of the recovery of very large volumes of water. Consequently, the development of the favorable well completion method to prevent water production is significantly important for realizing large scale hydrate exploitation in the future.http://dx.doi.org/10.1155/2018/5836293
spellingShingle Yilong Yuan
Tianfu Xu
Yingli Xia
Xin Xin
Effects of Formation Dip on Gas Production from Unconfined Marine Hydrate-Bearing Sediments through Depressurization
Geofluids
title Effects of Formation Dip on Gas Production from Unconfined Marine Hydrate-Bearing Sediments through Depressurization
title_full Effects of Formation Dip on Gas Production from Unconfined Marine Hydrate-Bearing Sediments through Depressurization
title_fullStr Effects of Formation Dip on Gas Production from Unconfined Marine Hydrate-Bearing Sediments through Depressurization
title_full_unstemmed Effects of Formation Dip on Gas Production from Unconfined Marine Hydrate-Bearing Sediments through Depressurization
title_short Effects of Formation Dip on Gas Production from Unconfined Marine Hydrate-Bearing Sediments through Depressurization
title_sort effects of formation dip on gas production from unconfined marine hydrate bearing sediments through depressurization
url http://dx.doi.org/10.1155/2018/5836293
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AT tianfuxu effectsofformationdipongasproductionfromunconfinedmarinehydratebearingsedimentsthroughdepressurization
AT yinglixia effectsofformationdipongasproductionfromunconfinedmarinehydratebearingsedimentsthroughdepressurization
AT xinxin effectsofformationdipongasproductionfromunconfinedmarinehydratebearingsedimentsthroughdepressurization