Analysis of stress regime in Shah Deniz oilfields and wellbore stability, in south Caspian Sea basin
Subject Areas :
Parvaneh
Alizadeh Saeid
1
Mohammad
Hassanpour sedghi
2
Ali
Kadkhodaie
3
Malek Mohammad
Gity
4
Keywords: Wellbore stabilityIn situ stress Oil and gas wells Stress regimeGeomechanics. ,
Abstract :
Wellbore instability is one of the main problems during drilling of oil and gas wells. Analyzing and wellbore instability prediction is important. In-situ stress measurement and stress regime are important for stability studies. This study was carried out in one of the oilfields in the south Caspian basin in Iran. The compressional stress regime in the studied field was determined based on regional stress indicators and larg scale tectonic observations. . This study presented the effect of borehole inclination and azimuth on borehole stability under reverse fault regimes. The magnitude of stresses was determined from measured sonic velocities, density log and predicted pore pressure utilizing the Eaton method. In this study, the modified Lade model have been utilized to perform stability calculation for different inclinations and azimuths. In this study, to perform stability calculation with the use of STABview software is presented. It is shown that drilling wells parallel to maximum in-situ horizontal stress (NE-SW) causes less stability problems. The results of this study could help in the mitigation and/ or prevention of wellbore stability issues in this oilfield.
آقانباتی، س.ع.، 1389.زمینشناسی ایران.سازمان زمینشناسی و اکتشافات معدنی کشور، 606 .
_مرتضی نژاد، غ.ر.، عزیز زنجانی، آ.، قدس، ع.ر. و ثبوتی، ف.، 1392. علوم زمین،تابستان 92، سال بیست و دوم، 88.2، 38-47.
_ Anderson, E.M. 1951. The dynamics of faulting and dike formation with application to Britain. Oliver and Boyd, 2nd Edition, Edinburgh, 133147.
_ Bonini, M., 2012. Mud volcanoes: Indicators of stress orientation and tectonic controls. Earth-Science Reviews 115, 121-152.
_ Bonini, M. and Mazzarini, F., 2010. Mud volcanoes as potential indicators of regional stress and pressurized layer depth. Tectonophysics.
_ Devlin, W., Cogswell, J., Gaskins, G., Isaksen, G., Pitcher, D., Puls, D., Stanley, K. and Wall, G., 1999. South Caspian Basin: young, cool, and full of promise. Geological Society of America Today, 9,7, 1-9.
_ Eaton, B.A., 1975. The equation for geopressure prediction from well logs. Society of Petroleum Engineers of AIME. Paper SPE, 5544
Fossen, H., 2010. Structural Geology. CAMBRIDGE UNIVERSITY PRESS._
Fowler, S.R., Mildenhall, J., Zalova, S., Riley, G., Elsley, G., Desplanques, A. and Guliyev, F., 2000. Mud volcanoes and structural development on Shah Deniz. Journal of Petroleum Science and Engineering.
_ Javanshir, Rashid J., Riley, Gregory W., Duppenbecker, Stephan J. and Abdullayev, N., 2015. Validation of lateralfluidflow in an overpressured sand-shale. Marine and Petroleum Geology.
_ Mclellan, P.J. and Hawkes, C.D., 2001. Borehole Stability Analysis for Underbalanced Drilling. Journal of Canadian Petroleum Technology, 40, 5, 31-38.
_ TERCAN, A.E., UNVER, B., TIRYAKI, B. and ÖZBILGIN, D., 2005. A study of relationships among mechanical, index and petrographic properties of some sandstones using canonical correlation analysis, (in Turkish). Mining, 44, 3-14.
_ Tixier, M.P., Loveless, G.W. and Anderson, R.A., 1975. Estimation of Formation Strength from the Mechanical Properties Log, SPE4532.
_ Zare, M.R., Shadizadeh, S.R. and Habibnia, B., 2010. Mechanical Stability Analysis of Directional Wells: A Case Study in Ahwaz. The 34th Annual SPE International Conference and Exhibition. Tinapa – Calabar, Nigeria.
_ Zoback, M.D., 2007. Reservoir Geomechanics, Cambridge University Press, 449.