Theory of lost circulation pressure

I. Morita, A. D. Black, G. F. Fuh

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    113 Citations (Scopus)

    Abstract

    Conventional theories predicting borehole breakdown pressure assume breakdown occurs when the tangential stress at the borehole exceeds the tensile strength of the formation. Fracturing tests conducted during the DEA-13 joint industry project, however, showed that when drilling fluid was used as an injection fluid, borehole breakdown did not occur until the well pressure significantly exceeded the pressure which resulted in a tangential stress equal to the rock tensile strength even with a large surface flaw. The test results have shown that all drilling muds have a tendency to seal narrow natural fractures or fractures created by high borehole pressure. The sealing effect of the mud stabilizes fractures and prevents fracture propagation. This effect is one of the primary factors for controlling wellbore stability. In this paper, a theory of fracture initiation and fracture propagation around a borehole whose stability is enhanced by drilling fluid interaction, has been developed and shown to be consistent not only with all the DEA-13 laboratory results, but also with various field evidence. The results show that lost circulation pressure is highly dependent on the Young's modulus of the formation, wellbore size, and type of the drilling fluid, although the conventional theories have ignored these facts.

    Original languageEnglish
    Title of host publicationProceedings - SPE Annual Technical Conference and Exhibition
    Editors Anon
    Place of PublicationRichardson, TX, United States
    PublisherPubl by Soc of Petroleum Engineers of AIME
    Pages43-58
    Number of pages16
    VolumeDelta
    Publication statusPublished - 1990
    EventProceedings: SPE Annual Technical Conference and Exhibition 1990 - New Orleans, LA, USA
    Duration: 1990 Sep 231990 Sep 26

    Other

    OtherProceedings: SPE Annual Technical Conference and Exhibition 1990
    CityNew Orleans, LA, USA
    Period90/9/2390/9/26

    ASJC Scopus subject areas

    • Geology
    • Geotechnical Engineering and Engineering Geology

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  • Cite this

    Morita, I., Black, A. D., & Fuh, G. F. (1990). Theory of lost circulation pressure. In Anon (Ed.), Proceedings - SPE Annual Technical Conference and Exhibition (Vol. Delta, pp. 43-58). Publ by Soc of Petroleum Engineers of AIME.