Sealing Form and Failure Mechanism of Deep In Situ Rock Core Pressure-Maintaining Controller

The mechanical properties of deep rocks change nonlinearly in an in situ pressure environment, so standard cores cannot be used as real samples for deep rock mechanics research. Therefore, obtaining an in situ pressure core is essential. However, the existing pressure-maintaining cores cannot overco...

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Main Authors: Nianhan Wu, Heping Xie, Ling Chen, Mingzhong Gao, Cong Li
Format: Article
Language:English
Published: Wiley 2020-01-01
Series:Geofluids
Online Access:http://dx.doi.org/10.1155/2020/8892720
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author Nianhan Wu
Heping Xie
Ling Chen
Mingzhong Gao
Cong Li
author_facet Nianhan Wu
Heping Xie
Ling Chen
Mingzhong Gao
Cong Li
author_sort Nianhan Wu
collection DOAJ
description The mechanical properties of deep rocks change nonlinearly in an in situ pressure environment, so standard cores cannot be used as real samples for deep rock mechanics research. Therefore, obtaining an in situ pressure core is essential. However, the existing pressure-maintaining cores cannot overcome the sealing capacity limit, largely due to the lack of consideration of sealing theory and experimental verifications of pressure-maintaining controllers. Therefore, this paper explores the sealing form and failure mechanism of pressure-maintaining controllers. The sealing state transition, pressure leakage, deformation failure theory, and test method for a pressure-maintaining controller are determined. Through theoretical analysis and experiments, (1) a seal-form discrimination method based on the chimeric curve is proposed to obtain the pressure seal conversion trend; (2) the leakage rate is exponentially related to the initial pressure, which confirms the pressure leakage principle of the pressure-maintaining controller; and (3) based on deformation failure theory for pressure-maintaining controllers, the failure mode and deformation trend are obtained through a destructive limit pressure experiment. The research results provide a theoretical basis and experimental support for improving pressure coring in deep rock and obtaining pressure cores at deep positions to construct a new conceptual system of deep in situ rock mechanics.
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issn 1468-8115
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language English
publishDate 2020-01-01
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series Geofluids
spelling doaj-art-25d3ed8dee284a3d8875bd741c90bce12025-02-03T06:05:35ZengWileyGeofluids1468-81151468-81232020-01-01202010.1155/2020/88927208892720Sealing Form and Failure Mechanism of Deep In Situ Rock Core Pressure-Maintaining ControllerNianhan Wu0Heping Xie1Ling Chen2Mingzhong Gao3Cong Li4School of Mechanical Engineering, Sichuan University, Chengdu 610065, ChinaState Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610065, ChinaSchool of Mechanical Engineering, Sichuan University, Chengdu 610065, ChinaState Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610065, ChinaState Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610065, ChinaThe mechanical properties of deep rocks change nonlinearly in an in situ pressure environment, so standard cores cannot be used as real samples for deep rock mechanics research. Therefore, obtaining an in situ pressure core is essential. However, the existing pressure-maintaining cores cannot overcome the sealing capacity limit, largely due to the lack of consideration of sealing theory and experimental verifications of pressure-maintaining controllers. Therefore, this paper explores the sealing form and failure mechanism of pressure-maintaining controllers. The sealing state transition, pressure leakage, deformation failure theory, and test method for a pressure-maintaining controller are determined. Through theoretical analysis and experiments, (1) a seal-form discrimination method based on the chimeric curve is proposed to obtain the pressure seal conversion trend; (2) the leakage rate is exponentially related to the initial pressure, which confirms the pressure leakage principle of the pressure-maintaining controller; and (3) based on deformation failure theory for pressure-maintaining controllers, the failure mode and deformation trend are obtained through a destructive limit pressure experiment. The research results provide a theoretical basis and experimental support for improving pressure coring in deep rock and obtaining pressure cores at deep positions to construct a new conceptual system of deep in situ rock mechanics.http://dx.doi.org/10.1155/2020/8892720
spellingShingle Nianhan Wu
Heping Xie
Ling Chen
Mingzhong Gao
Cong Li
Sealing Form and Failure Mechanism of Deep In Situ Rock Core Pressure-Maintaining Controller
Geofluids
title Sealing Form and Failure Mechanism of Deep In Situ Rock Core Pressure-Maintaining Controller
title_full Sealing Form and Failure Mechanism of Deep In Situ Rock Core Pressure-Maintaining Controller
title_fullStr Sealing Form and Failure Mechanism of Deep In Situ Rock Core Pressure-Maintaining Controller
title_full_unstemmed Sealing Form and Failure Mechanism of Deep In Situ Rock Core Pressure-Maintaining Controller
title_short Sealing Form and Failure Mechanism of Deep In Situ Rock Core Pressure-Maintaining Controller
title_sort sealing form and failure mechanism of deep in situ rock core pressure maintaining controller
url http://dx.doi.org/10.1155/2020/8892720
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AT lingchen sealingformandfailuremechanismofdeepinsiturockcorepressuremaintainingcontroller
AT mingzhonggao sealingformandfailuremechanismofdeepinsiturockcorepressuremaintainingcontroller
AT congli sealingformandfailuremechanismofdeepinsiturockcorepressuremaintainingcontroller