Doctoral Dissertations

Abstract

"Lost circulation (LOC) problems increase costs of drilling significantly. It is not only the cost of the drilling fluid that is lost into the formation but also the costs of subsequent problems that can be higher than the cost of the drilling fluids. LOC also possibly leads to a serious risk of blowout incident.

Lost circulation materials (LCM) are regularly added to the drilling fluids with an expectation of plugging the flow path. Due to the difficulties of testing and monitoring LCM sealing processes in the field, LCM evaluation in the laboratory is often used to prove and assure successful treatment. Investigating LCM behavior and the causation of obtaining different results would expand the reliability of the laboratory evaluation methods.

In this study, a steel cylindrical cell was used to simulate downhole high-pressure conditions. Steel discs with precisely sized slots (simulating wellbore fractures) were used to study the effect of testing conditions on the particulate LCM sealing performance. Results show that the fracture wall angles, the disc thickness, the base fluids, the drilling fluid density, the particle size of weighting materials related to the LCM grain sizes, and the dynamic aging conditions all affect the testing results significantly. LCM that performed well in the slow injection rate tests also exhibited sealing behavior effectively in the instantaneous flow conditions. The experiments provided an understanding of the fracture sealing mechanism to be applied in improving the laboratory evaluation methods and field treatment design. This knowledge is useful for both the preventive and corrective LOC mitigating approaches"--Abstract, page iv.

Advisor(s)

Nygaard, Runar

Committee Member(s)

Nygaard, Runar
Flori, Ralph E.
Dunn-Norman, Shari
Heidari, Peyman
Gertsch, Leslie S.

Department(s)

Geosciences and Geological and Petroleum Engineering

Degree Name

Ph. D. in Petroleum Engineering

Sponsor(s)

Defense Energy Department (Thailand)
Aker BP ASA

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2017

Journal article titles appearing in thesis/dissertation

  • Testing conditions make a difference when testing LCM
  • Effect of testing conditions on the performance of lost circulation material: understandable sealing mechanism
  • Sealing pressure prediction model for lost circulation treatments based on experimental investigations
  • Effect of experimental setup on lost circulation materials evaluation results

Pagination

xii, 123 pages

Note about bibliography

Includes bibliographic references.

Rights

© 2017 Montri Jeennakorn, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 11172

Electronic OCLC #

1003043404

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