IDEAS home Printed from https://ideas.repec.org/a/gam/jeners/v11y2018i10p2557-d171999.html
   My bibliography  Save this article

Impact of Casing Eccentricity on Cement Sheath

Author

Listed:
  • Kui Liu

    (College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102200, China)

  • Deli Gao

    (College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102200, China)

  • Arash Dahi Taleghani

    (Department of Energy and Mineral Engineering, Pennsylvania State University, University Park, PA 16802, USA)

Abstract

Sustained casing pressure (SCP) in shale gas wells caused by cement sheath failure can have serious impacts on safe and efficient gas production. Considering the fact that horizontal wells are widely used for production from shale, the cementing quality and casing centricity is barely ensured in these wells. Among other indications, the casing eccentricity is identified very often in wells with SCP problems in the Sichuan field in China. Hence, the objective of this study is to analyze the effect of the casing eccentricity on the integrity of the cement sheath. To better understand stress distribution in eccentric cement sheaths, an analytical model is proposed in this paper. By comparing the results of this model with the one’s with centric casing, the impacts of the casing eccentricity on the integrity of the cement sheath is analyzed. During fracturing treatments, the casing eccentricity has a little effect on stress distribution in the cement sheath if the well is well cemented and bonded to the formation rock. However, on the contrary, the casing eccentricity may have serious effects on stress distribution if the cementing is done poorly. The debonding of casing–cement–formation interfaces can significantly increase the circumferential stress in the cement sheath. At the thin side of the cement sheath, the circumferential stress could be 2.5 times higher than the thick side. The offset magnitude of the casing eccentricity has little effect on the radial stress in the cement sheath but it can significantly increase the shear stress. We found that the risk of cement failure may be reduced by making the casing string more centralized, or increasing the thickness of the casing. The results provide insights for design practices which may lead to better integrity in shale gas wells.

Suggested Citation

  • Kui Liu & Deli Gao & Arash Dahi Taleghani, 2018. "Impact of Casing Eccentricity on Cement Sheath," Energies, MDPI, vol. 11(10), pages 1-19, September.
    • Handle: RePEc:gam:jeners:v:11:y:2018:i:10:p:2557-:d:171999
    as

    Download full text from publisher

    File URL: https://www.mdpi.com/1996-1073/11/10/2557/pdf
    Download Restriction: no
    File URL: https://www.mdpi.com/1996-1073/11/10/2557/
    Download Restriction: no
    ---><---

    References listed on IDEAS

    as
    1. Mingtao Fan & Jun Li & Gonghui Liu, 2018. "New Method to Analyse the Cement Sheath Integrity During the Volume Fracturing of Shale Gas," Energies, MDPI, vol. 11(4), pages 1-16, March.
    Full references (including those not matched with items on IDEAS)

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Haoyu Dou & Xuelin Dong & Zhiyin Duan & Yinji Ma & Deli Gao, 2020. "Cement Integrity Loss due to Interfacial Debonding and Radial Cracking during CO 2 Injection," Energies, MDPI, vol. 13(17), pages 1-18, September.

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Yuqiang Xu & Yan Yan & Shenqi Xu & Zhichuan Guan, 2020. "Numerical Simulation Study on Propagation of Initial Microcracks in Cement Sheath Body during Hydraulic Fracturing Process," Energies, MDPI, vol. 13(5), pages 1-18, March.
    2. Muhammad Shahzad Kamal & Marwan Mohammed & Mohamed Mahmoud & Salaheldin Elkatatny, 2018. "Development of Chelating Agent-Based Polymeric Gel System for Hydraulic Fracturing," Energies, MDPI, vol. 11(7), pages 1-15, June.

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:gam:jeners:v:11:y:2018:i:10:p:2557-:d:171999. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: MDPI Indexing Manager (email available below). General contact details of provider: https://www.mdpi.com .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.