OPTIMIZING WELLBORE INCLINATION AND AZIMUTH TO MINIMIZE INSTABILITY PROBLEMS

Abouzar Mirzaei Paiaman, Saman Azadbakht, Bandar Duraya Al-Anazi

Аннотация


Wellbore stability is of critical importance in the success of drilling operations. One of the main goals of any drilling mission is to drill the well as cost-effective as possible. Wellbore instability can be detrimental to this goal. Therefore, wellbore stability analysis has been included in well planning stage of many companies.
Wellbore stability is a function of several factors such as inclination and azimuth, in-situ stresses, mud weight, rock strength parameters, etc. Some of these factors are controllable and some are not. Among the controllable factors are inclination, azimuth and mud weight. By changing these parameters, one can reduce stability problems significantly. Theoretically, it is possible to design the well trajectory in a way to face least stability problems.
In this paper linear elastic constitutive model along with Mohr-Coulomb failure criterion have been utilized to perform stability calculation for different inclinations and azimuths. It is shown that drilling wells parallel to minimum in-situ horizontal stress causes less stability problems. Also the effect of in-situ stress field on wellbore stability has been investigated and it has been demonstrated that in the case of high difference between the in-situ stresses, the optimum path for a well is a low inclination and an intermediate azimuth.

Полный текст:

PDF

Литература


>1. Maury, V. Rock Failure Mechanisms Identification: A Key for Wellbore Stability and Reservoir Behavior Problem, paper SPE 28049, presented at the SPE/ISRM Rock Mechanics in Petroleum Engineering Conference, Delft, Netherlands, 29-31 August, 1994.

2. McLean, M.R. and Addis, M.A. Wellbore Stability Analysis: A Review of Current Methods of Analysis and Their Field Application, paper IADC/SPE 19941, presented at the IADC/SPE Drilling Conference, Houston, Texas, February 27 – March 2, 1990.

3. Lowery, J.P. and Ottesen, S. An Assessment of Mechanical Stability of Wells Offshore Nigeria, SPE Drilling & Completion, march 1995.

4. McLean, M.R. and Addis, M.A. Wellbore Stability: The Effect of Strength Criteria on Mud Weight Recommendations, paper SPE 20405, presented at the 65th Annual Technical Conference and Exhibition of SPE, New Orleans, September 23-26, 1990.

5. Zhou, S. and Hillis, R.R. and Sandiford, M. On the Mechanical Stability of Inclined Wellbores, SPE Drilling & Completion, June 1996.

6. Aadnoy, B.S., and Chenevert, M.E. Stability of Highly Inclined Boreholes, SPE Drilling Engineering , December 1987.

7. Charlez, P.A. Rock Mechanics, Vol. 2 , Petroleum Applications, Editions Technip.

8. Fjaer, E. Petroleum Related Rock Mechanics, Elsevier Publications, 1992.

9. Aadnoy, B.S. Modeling of Stability of Highly Inclined Boreholes in Anisotropic Rock Formations, SPE Drilling Engineering, September 1988.

10. Chen, X., Tan, C.P., Haberfield, C.M.Guidelines for Efficient Wellbore Stability Analysis, Intl. J. Rock Mech. Min. Sci. & Geom. Abst. Vol 34, No 3/4, 1997.


Ссылки

  • На текущий момент ссылки отсутствуют.