Article
Development of Hydraulic Turbodrills for Deep Well Drilling
Mikhail V. Dvoynikov, Dmitry I. Sidorkin *, Andrey A. Kunshin and Danil A. Kovalev
Citation: Dvoynikov, M.V.;
Sidorkin, D.I.; Kunshin, A.A.;
Kovalev, D.A. Development of
Hydraulic Turbodrills for Deep Well
Drilling. Appl. Sci. 2021, 11, 7517.
https://doi.org/10.3390/app11167517
Academic Editor: José A.F.O. Correia
Received: 20 July 2021
Accepted: 11 August 2021
Published: 16 August 2021
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Arctic Competence Center, Saint Petersburg Mining University, 199106 Saint Petersburg, Russia;
Dvoynikov_MV@pers.spmi.ru (M.V.D.); Kunshin_A2@pers.spmi.ru (A.A.K.);
s170567@mail.stud.spmi.ru (D.A.K.)
* Correspondence: Sidorkin_DI@pers.spmi.ru
Abstract:
The article discusses the possibility of improving the design of the turbine of a hydraulic
drilling machine for drilling wells in very hard rocks and at considerable depths (5000–12,000 m).
The analysis of the results of studies on the technical and technological characteristics of downhole
drilling motors showed that it is impossible to ensure stable operation due to the limitation on the
operating temperature, while with an increase in the flow rate of the drilling fluid, they do not provide
the required power on the spindle shaft, and cannot reach high-speed drilling. In such conditions,
turbodrills with a significant change in the profile of the stator and rotor blades and a reinforced
support unit are most suitable. The paper presents an invariant mathematical model, which made it
possible to determine the optimal geometric parameters based on preselected boundary conditions
and the main performance characteristics of the turbine being developed. The results obtained
were tested by the finite element method, which showed a convergence of 12.5%. At the same time,
zones with the lowest and highest flow rates were identified. Additionally, this paper presents
a comparative analysis of the obtained hydraulic turbine with turbodrills of the TSSH-178T and
Neyrfor TTT 2 7/8 brands. In comparison with the domestic turbodrill, the developed turbine design
shows a 13-fold reduction in its length and a 3-fold reduction in torque, provided that the maximum
power is increased by 1.5 times. In comparison with the foreign analog, there is a decrease in length
by 8.5 times, an increase in torque by 5 times, and in maximum power by 6.5 times.
Keywords:
drilling of wells; high-speed drilling; hydraulic downhole motor; increasing the en-
ergy efficiency of drilling; development of a turbodrill; optimization by the trusted region; finite
element method
1. Introduction
All over the world, countries are interested in drilling deep and ultra-deep wells.
Each country has its own interest; some need production wells and some need research
wells [1,2]. However, they are united by the complexity of drilling such wells because the
work is carried out in very hard rocks at high temperatures and using high-density drilling
mud [3–5].
Currently, existing technologies do not allow for effective drilling in such conditions
due to the fact that the loads on the drill string, bit, and hydraulic motor increase [6–8].
The most common downhole screw motors are unable to operate under these condi-
tions due to the significant temperature limitation (up to 150
◦
C) [
9
–
11
]. In addition, their
indisputable advantages in the field of creating significant torque elements at low speeds
lead to the inappropriateness of their use in these conditions [12–14].
Based on the foregoing, the most effective technology for drilling such wells is the use
of impregnated bits in combination with a high-speed hydraulic turbine engine [15,16].
The first turbine apparatus for drilling wells was developed in 1923 by M.A. Kape-
lyushnikov, together with S.M. Volokh. and Kornev N.A., called the Kapelyushnikov
turbodrill (12 HP, single-stage turbine, multi-stage planetary gearbox). The final design of
the turbodrill, which has become widespread, was created by PP Shumilov, RA Ioannesyan,
EI Tagiyev, and MT Gusman [17,18].
Appl. Sci. 2021, 11, 7517. https://doi.org/10.3390/app11167517 https://www.mdpi.com/journal/applsci
