«Onshore and offshore oil and gas well construction»

Building an 1D geomechanical model for complicated geological conditions using the example of a South Caspian field

UDC: 622.24.001
DOI: -

Authors:

¹ PermNIPIneft, Perm, Russia

Keywords: shelf, 1D geomechanical modeling, well logging, tectonic disturbances (faults), abnormally high reservoir pressure, stress calculation, pore pressure, wellbore stability, well design, optimal drilling fluid density

Annotation:

The authors of the article present the principles and results of 1D geomechanical modeling, developed to reduce the risks of complications during wells construction. The working area is located on the shelf in the southern part of the Caspian Sea. Among specific features of the area under consideration, its complicated geological-tectonic composition is noted. According to the seismic and geological model of the field under study, a number of tectonic disturbances (faults) of different types and genesis have been identified, including mud volcanism and clayey diapirism, which influence the stress-strain state of the environment. In order to construct a three-dimensional (3D) geomechanical model for the given area, a multi-stage approach to one-dimensional (1D) geomechanical modeling is considered, including the results of vertical and horizontal stresses calculation, a pore pressure profile construction, determination of dynamic and static elastic-strength characteristics of rocks in the field under study . Based on the results of 1D geomechanical modeling, stability calculations for six reference wells were obtained and analyzed. Taking into account the obtained geomechanical and engineering calculations, the gradients of pore pressure, collapse pressure, absorption and hydraulic fracturing were determined, and a safe window of drilling fluid density was established.

Bibliography:

1. Optimizatsiya konstruktsiy i traektoriy proektnykh skvazhin po rezul'tatam postroeniya 1D geomekhanicheskikh modeley na primere mestorozhdeniy Kaspiyskogo morya / P.I. Klykov, G.V. Zverev, I.A. Petrenko, A.V. Nagovitsin // Oborudovanie i tekhnologii dlya neftegazovogo kompleksa. – 2023. – № 6(138). – S. 29–35. – DOI: 10.33285/1999-6934-2023-6(138)-29-35
2. Khilterman F.Dzh. Interpretatsiya amplitud v seysmorazvedke / per. s angl. I. Artem'evoy, A. Cherepovskogo; pod red. G. Goloshubina, A. Cherepovskogo. – Tver': GERS, 2010. – 251 s.
3. Lyadova N.A., Klykov P.I., Predein A.A. Chislennoe reshenie zadach geomekhaniki (na primere mestorozhdeniya shel'fa Baltiyskogo morya) // Vestn. PNIPU. Geologiya. Neftegazovoe i gornoe delo. – 2020. – T. 20, № 2. – S. 126–136. – DOI: 10.15593/2224-9923/2020.2.3
4. Eaton B.A. The Equation for Geopressure Prediction from Well Logs // Fall Meeting of the Society of Petroleum Engineers of AIME, Dallas, Texas, Sept. 28 – Oct. 1, 1975. – DOI: 10.2118/5544-MS
5. Geomekhanicheskoe modelirovanie razreza mestorozhdeniya sakhalinskogo shel'fa pod zadachi bureniya skvazhin / T.Yu. Lukina, A.G. Potapov, O.E. Bogdanova, O.A. Potapov // Nauch.-tekhn. sb. Vesti gazovoy nauki. – 2017. – № 4(32). – S. 159–168.
6. Mohr-Coulomb Yield Criterion in Rock Plastic Mechanics / Wang Hong-Cai, Zhao Wei-Hua, Sun Dong-Sheng, Guo Bin-Bin // Chinese J. of Geophysics. – 2012. – Vol. 55, Issue 6. – P. 733–741. – DOI: 10.1002/cjg2.1767
7. Al-Ajmi A.M., Zimmerman R.W. Stability analysis of vertical boreholes using the Mogi-Coulomb failure criterion // Int. J. of Rock Mechanics and Mining Sciences. – 2006. – Vol. 43, Issue 8. – P. 1200–1211. – DOI: 10.1016/J.IJRMMS.2006.04.001
8. Ewy R.T. Wellbore-Stability Predictions by Use of a Modified Lade Criterion // SPE Drilling & Completion. – 1999. – Vol. 14, Issue 2. – P. 85–91. – DOI: 10.2118/56862-PA
9. Baykovskiy D.I. Opredelenie optimal'nogo napravleniya traektorii bureniya gorizontal'nogo stvola s uchetom vektora glavnykh gorizontal'nykh napryazheniy dlya povysheniya effektivnosti gidravlicheskogo razryva plasta // Oborudovanie i tekhnologii dlya neftegazovogo kompleksa. – 2022. – № 6(132). – S. 40–48. – DOI: 10.33285/1999-6934-2022-6(132)-40-48