Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Study on Sealing Failure of Wellbore in Bedded Salt Cavern Gas Storage
https://orcid.org/0000-0002-0529-5667
Abstract The wellbore tightness of a salt cavern gas storage must be tested before solution mining. According to the test results, it will be evaluated whether the wellbore can meet the cementing requirements of gas storage. However, there are many complex reasons that may cause wellbore leakage; hence, how to comprehensively analyze the test results and accurately expose the causes, locations, and scale of the leakage pose many challenges. These mainly include the incomplete test method and lack of theoretical analysis model. A nitrogen leak test was carried out for five wellbores that have been completed in Jintan (Jiangsu, China). The results show that two of them had leakage risk. To clarify the leakage causes and leakage types, we carried out an investigation of engineering geological data of the wellbores and further conducted laboratorial tests and theoretical analysis. The studies of drilling design and engineering geology show that the wellbores have good integrity and initially reveal that a mudstone interlayer intersecting the open hole between the casing shoe and the top of the salt cavern is a potential leaking layer. Furthermore, the permeability experiments and CT scans confirm that this mudstone interlayer is a leaking stratum and that the internal cracks develop severely. They are the key reasons leading to wellbore tightness failure. The proposed seepage theoretical model determines that the leakage type is horizontal flow in the mudstone interlayer. Comparing the theoretical results with the field test data, we find that the leakage rate curves of the two are in good agreement, which completely confirms that the mudstone interlayer is the fundamental cause of the wellbores tightness failure. This research not only identifies the leakage causes and leakage types of wellbores, but also enriches the leakage rate analysis method of gas storage and provides a theoretical and experimental analysis method for tightness evaluation of bedded salt cavern storage.
Study on Sealing Failure of Wellbore in Bedded Salt Cavern Gas Storage
https://orcid.org/0000-0002-0529-5667
Abstract The wellbore tightness of a salt cavern gas storage must be tested before solution mining. According to the test results, it will be evaluated whether the wellbore can meet the cementing requirements of gas storage. However, there are many complex reasons that may cause wellbore leakage; hence, how to comprehensively analyze the test results and accurately expose the causes, locations, and scale of the leakage pose many challenges. These mainly include the incomplete test method and lack of theoretical analysis model. A nitrogen leak test was carried out for five wellbores that have been completed in Jintan (Jiangsu, China). The results show that two of them had leakage risk. To clarify the leakage causes and leakage types, we carried out an investigation of engineering geological data of the wellbores and further conducted laboratorial tests and theoretical analysis. The studies of drilling design and engineering geology show that the wellbores have good integrity and initially reveal that a mudstone interlayer intersecting the open hole between the casing shoe and the top of the salt cavern is a potential leaking layer. Furthermore, the permeability experiments and CT scans confirm that this mudstone interlayer is a leaking stratum and that the internal cracks develop severely. They are the key reasons leading to wellbore tightness failure. The proposed seepage theoretical model determines that the leakage type is horizontal flow in the mudstone interlayer. Comparing the theoretical results with the field test data, we find that the leakage rate curves of the two are in good agreement, which completely confirms that the mudstone interlayer is the fundamental cause of the wellbores tightness failure. This research not only identifies the leakage causes and leakage types of wellbores, but also enriches the leakage rate analysis method of gas storage and provides a theoretical and experimental analysis method for tightness evaluation of bedded salt cavern storage.
Study on Sealing Failure of Wellbore in Bedded Salt Cavern Gas Storage
https://orcid.org/0000-0002-0529-5667
Abstract The wellbore tightness of a salt cavern gas storage must be tested before solution mining. According to the test results, it will be evaluated whether the wellbore can meet the cementing requirements of gas storage. However, there are many complex reasons that may cause wellbore leakage; hence, how to comprehensively analyze the test results and accurately expose the causes, locations, and scale of the leakage pose many challenges. These mainly include the incomplete test method and lack of theoretical analysis model. A nitrogen leak test was carried out for five wellbores that have been completed in Jintan (Jiangsu, China). The results show that two of them had leakage risk. To clarify the leakage causes and leakage types, we carried out an investigation of engineering geological data of the wellbores and further conducted laboratorial tests and theoretical analysis. The studies of drilling design and engineering geology show that the wellbores have good integrity and initially reveal that a mudstone interlayer intersecting the open hole between the casing shoe and the top of the salt cavern is a potential leaking layer. Furthermore, the permeability experiments and CT scans confirm that this mudstone interlayer is a leaking stratum and that the internal cracks develop severely. They are the key reasons leading to wellbore tightness failure. The proposed seepage theoretical model determines that the leakage type is horizontal flow in the mudstone interlayer. Comparing the theoretical results with the field test data, we find that the leakage rate curves of the two are in good agreement, which completely confirms that the mudstone interlayer is the fundamental cause of the wellbores tightness failure. This research not only identifies the leakage causes and leakage types of wellbores, but also enriches the leakage rate analysis method of gas storage and provides a theoretical and experimental analysis method for tightness evaluation of bedded salt cavern storage.
Study on Sealing Failure of Wellbore in Bedded Salt Cavern Gas Storage
Chen, Xiangsheng (Autor:in) / Li, Yinping (Autor:in) / Liu, Wei (Autor:in) / Ma, Hongling (Autor:in) / Ma, Jianli (Autor:in) / Shi, Xilin (Autor:in) / Yang, Chunhe (Autor:in)
2018
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
BKL:
38.58
Geomechanik
/
56.20
Ingenieurgeologie, Bodenmechanik
/
38.58$jGeomechanik
/
56.20$jIngenieurgeologie$jBodenmechanik
RVK:
ELIB41
Study on Sealing Failure of Wellbore in Bedded Salt Cavern Gas Storage
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