Effects of Long-term Development on Wellbore Stability: A Case Study of Bohai Bay Basin
Yuan Jun-Liang1, *, Deng Jin-Gen1, Tan Qiang1, Yu Bao-Hua1, Fan Bai-Tao2
Identifiers and Pagination:Year: 2013
First Page: 1
Last Page: 6
Publisher Id: TOPEJ-6-1
Article History:Received Date: 16/07/2012
Revision Received Date: 24/10/2012
Acceptance Date: 28/10/2012
Electronic publication date: 9/1/2013
Collection year: 2013
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
This paper describes the method used in the depleted reservoir for analyzing horizontal in-situ stresses in order to define a stable mud weight window to maximize the efficiency of drilling process. The method combines wellbore stability modeling, in-situ stress prediction, and pore pressure depletion during production process. In the presence of any hydraulically isolated fault blocks or other permeability barriers, the pore pressure depletion will cause horizontal stress changes in both magnitude and orientation. Furthermore, the changes of horizontal stress affect the wellbore stability of inclined wells. The results indicate that the reservoir depletion has notable effect on the safe mud weight window, especially the fracture pressure. The fracture pressure may be overestimated in previous model, and the most stable well azimuth is not static but varies over the lifetime of the oilfield. The research conclusions can provide significant reference for the mud weight design of directional well in depleted reservoir.