THERMAL SCIENCE

International Scientific Journal

Ding-Ming Wang

,

Ling Chen

,

Da Guo

,

Zhi-Qiang Liu

,

Ju Li

,

Xun Yang

,

Yi-Wei Zhang

DISCRETE ELEMENT ANALYSIS ON THE INFLUENCE OF DRILLING FLUID PRESSURE ON CORE DISCING IN PRESSURE-PRESERVED CORING

ABSTRACT
In the process of coring in a high in-situ stress environment, the rock core is damaged due to stress release, and core discing is a prominent manifestation of this damage. Pressure-preserved coring has no direct effect on in-situ stress, and its influence on stress release is related to drilling fluid pressure. Yet fluid pressure in the coring process was not considered in most former numerical simulation studies on core discing. In this paper, the discrete element method software PFC3D is used to conduct a numerical simulation of the coring process. According to the two conditions without drilling fluid pressure and with it, and different horizontal in-situ stresses of 5-160 MPa, fracture and discing of the core with drilling are observed. In addition, the law of fracture and discing in the process of coring was studied, and the function of pressure-preserved coring to prevent fracture and discing is explored. Simulation results show nonlinear trends in distribution of discs both in time and in space.
KEYWORDS
pressure-preserved coring, core discing, discrete element, drilling fluid pressure
PAPER SUBMITTED: 2022-08-17
PAPER REVISED: 2022-11-18
PAPER ACCEPTED: 2022-11-29
PUBLISHED ONLINE: 2023-03-04
DOI REFERENCE: https://doi.org/10.2298/TSCI2301655W
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2023, VOLUME 27, ISSUE Issue 1, PAGES [655 - 665]
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Discrete element analysis on the influence of drilling fluid pressure on core discing in pressure-preserved coring

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence