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Calculation of distance between elastic-rigid centralizers of casing

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Category: Mining

Last Updated on 17 November 2017

Published on 17 November 2017

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Authors:

І.I.Vytvytskyi, Ivano-Frankivsk National Technical University of Oil and Gas, assistant, Ivano-Frankivsk, Ukraine, е-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it.

M.V.Seniushkovych, Cand. Sc. (Tech.), Assoc. Prof., Ivano-Frankivsk National Technical University of Oil and Gas, Associate Professor, Ivano-Frankivsk, Ukraine, е-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it.

I.P.Shatskyi, Dr. Sc. (Phys.-Math.), Prof., Ivano-Frankivsk Branch of Pidstryhach Institute for Applied Problems of Mechanics and Mathematics NAS of Ukraine, Ivano-Frankivsk, Ukraine, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract:

Purpose. Formulation and solution to the problem of rational centering of the casing under the complex configuration of well axis using elastic-rigid centralizers.

Methodology. The model of the “casing-well” system is under consideration. In the simulation system, the column in the hole is loaded by two sets of forces: the forces of gravity, distributed along the axis of the pipe and pressure forces caused by the complex configuration of the well axis and distributed between the centering devices. The influence of structural peculiarities of the cyclically symmetric “bow” type centralizers on their rigidity and toughness characteristics has been taken into account. The solution of the problem will be considered found when the allowable minimum value of a gap in the “casing-well-wall” system is provided.

Findings. The dependencies to determine the distance between the centralizers and allowable gap have been determined on the basis of the solution of the problem of rod bending on the elastic-rigid supports. With the increase in zenith angle due to increased transverse component of gravity, the distance between centralizers reduces. Moreover, for small zenith angles it is even smaller, due to greater downforce. For large zenith angle as well as for large pressing forces, their influence on the distance between the centering devices is offset due to activation of the stop. In particular, it was determined that the stop of a centralizer provided it has sufficient strength can guarantee the required gap at considerable loads on the column. The results of the research have been approved by the engineering calculations for specific sizes of casing and well.

Originality. New dependencies to calculate the distance between the elastic-rigid centralizers used in casing the well taking into consideration groups of factors that determine the wellbore profile and centralizer specifications have been established.

Practical value. The obtained results provide for optimizing the exact number and intervals of equipping the casing with centering devices and thereby avoid the formation of dead zones in the annulus. This will give the opportunity to achieve high-quality cement job and make casing of the well of any configuration reliable and time-proof.

References:

1. Iohansen, K. V., 2012. Driller’s assistant. Simferopol: Biznes-inform.

2. RD 39-7/1-0001-97, 1997. Manual on casing design for oil and gas wells. Moscow.

3. RD 39-00147001-767-2000, 2000. Manual on oil and gas well cementing. OAO “Gazprom”, Russia.

4. Mysliuk, M. A. and Rybchych, I. I., 2012. Wells completion. In: M. A Mysliuk and I. I. Rybchych, 2012. Well drilling. Kyiv: Interpres Ltd. V. 4.

5. Larin, P. A., Gutorov, Yu. A. and Yakunina, S. N., 2013. Problems of qualitative cementing of wells with intricate profile. RKNTC.

6. Kotskulych, Ya. S., Seniushkovych, M. V., Martsynkiv, O. B. and Vytvytskyi, I.I., 2015. Casing string centering in directional wells. Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, 3, pp. 23–30.

7. Shatskyi, I. P., Biletskyi, Ya. S. and Vytvytskyi, I. I., 2014. Two-side estimates of rigidity and strength of casing centralizer. Odeskyi politekhnichnyi universytet. Pratsi, 1, pp. 68–73.

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2017-11-15  2.01 MB  862

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