Please use this identifier to cite or link to this item:
Scopus Web of Science® Altmetric
Type: Journal article
Title: Welbore failure induced by formation testing
Author: Hillis, R.
Thomas, S.
Citation: Petroleum Geoscience, 1999; 5(3):235-239
Publisher: Geological Society Publishing House
Issue Date: 1999
ISSN: 1354-0793
Statement of
Richard R. Hillis and Simon D. Thomas
Abstract: Five formation tests were undertaken in well 110/8A-5 in the Irish Sea. Pressures within the tested intervals were reduced from 16–17 MPa to c. 10 MPa. The tested intervals, which were subsequently logged by an electrical imaging tool, exhibit zones of low resistivity on opposite sides of the wellbore wall. These zones are restricted to the tested intervals and interpreted as borehole breakouts. It is inferred that the reduction in wellbore pressure associated with testing increased the stress acting on the wellbore wall, leading to failure. This confirms that such wellbore failure can be induced by reducing mud weight. Maximum horizontal stress is inferred to be orientated east–west which has implications for reservoir development, because natural and induced fluid flow will tend to be focused in that direction. With regard to the formation tests, near wellbore fracturing may result in modelled permeabilities exceeding those associated with intact reservoir rocks.
Keywords: Pressure drawdown text
borehole breakout
Rights: GeoRef, Copyright 2008, American Geological Institute.
DOI: 10.1144/petgeo.5.3.235
Published version:
Appears in Collections:Aurora harvest 7
Geology & Geophysics publications

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.