Kinetic characteristics analysis of a new torsional oscillator based on impulse response

Proceedings of the Institution of Mechanical Engineers, Part K:

Wang

Zhou

et al. 2021

Self Cite

Excessive stick–slip vibration of drill strings can cause inefficiency and unsafety of drilling operations. To suppress the stick–slip vibration that occurred during the downhole drilling process, a drill string torsional vibration system considering the torsional vibration tool has been proposed on the basis of the 4-degree of freedom lumped-parameter model. In the design of the model, the tool is approximated by a simple torsional pendulum that brings impact torque to the drill bit. Furthermore, two sliding mode controllers, U1 and U2, are used to suppress stick–slip vibrations while enabling the drill bit to track the desired angular velocity. Aiming at parameter uncertainty and system instability in the drilling operations, a parameter adaptation law is added to the sliding mode controller U2. Finally, the suppression effects of stick–slip and robustness of parametric uncertainty about the two proposed controllers are demonstrated and compared by simulation and field test results. This paper provides a reference for the suppression of stick–slip vibration and the further study of the complex dynamics of the drill string.

Section: Theoretical Modelsmentioning

confidence: 99%

Study of stick–slip suppression and robustness to parametric uncertainty in drill strings containing torsional vibration tool using sliding-mode control

Proceedings of the Institution of Mechanical Engineers, Part K:

Wang

Zhou

et al. 2021

Self Cite

“…Based on the Ritto et al 17,18 model and the Eva and Navarro-Lopez model, 19,20 a multi-degreeof-freedom drill column visco-slip vibration model with the new torsional vibration tool is established, as shown in Figure 3. The following assumptions are made on the stick-slip vibration model of the multi-degree-of-freedom drill string:(1) the drill string system is in a vertical well; (2) both the drill string and the torsional vibration tool are elastically deformed, the mass is evenly distributed, and the axis of the drill string coincides with the axis of the wellbore; (3) the rotational speed of the top rotary mechanism is constant; (4) the top rotary mechanism, drill pipes, drill collars, drill tool and drill bit are concentrated masses, and they are connected by springs and damping of equivalent torsional stiffness; (5) the friction between the drill bit and the rock, the drill string and the well wall is replaced by a concentrated friction torque.…”

Section: Theoretical Modelmentioning

confidence: 99%

“…And the hazard of stick-slip vibration in the axial vibration is the most serious, which greatly accelerates the failure of the drill strings and the drill bits and causes the breakdown of the ground equipment, and it has a strong impact on the drilling process and will increase the drilling cost. [5][6][7] In order to develop control and optimize strategies for stick-slip vibration of the drill strings, a great deal of theoretical and experimental research surrounding drill-string dynamics have been carried out in the past years. Zribi et al 8 simplified the drill string system into three concentrated masses and proposed an alternative method to describe the stick-slip vibration of the drill string system.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of stick-slip reduction for a new torsional vibration tool based on PID control

Proceedings of the Institution of Mechanical Engineers, Part K:

Zhou

Yang

et al. 2019

Self Cite

The phenomenon of stick-slip vibration is widespread in the exploration of deep and ultra-deep wells. It causes the reduction of the mechanical drilling rate and wastes the driving energy. Besides, it also accelerates the aging and failure of the drill strings and threatens the safety of drilling seriously. In order to effectively control the stick-slip vibration of the drill string, a new type of torsional vibration tool is proposed in this paper firstly. Then, the theoretical model of the drill string system based on the tool is established. And then, the viscosity reduction characteristics of the new torsional vibration tool are studied by the PID control method. Finally, field tests were carried out in comparison with simulation. The results show that the new torsional vibration tool can reduce the stick-slip vibration. And the two PID control equations can both control the drill bit speed in real time through changing the turntable speed. The results also have important reference significance for reducing and controlling the stick-slip vibration of the drill string and improving the rock-breaking efficiency.

“…Therefore, the research on the dynamics of the drill string related to the vibration of the drill string has become a hot topic in current research and the related research has important economic benefits and practical guiding significance [10][11][12][13]. During the drilling process, when the hard formation is encountered, it is necessary to increase the weight of the drill or replace the drill bit to achieve the rock fracture [14][15][16]. However, in the horizontal well, as the horizontal displacement increases, the pressure is often decomposed, resulting in the failure to apply the weight evenly.…”

Section: Introductionmentioning

confidence: 99%

Study on the mechanism of drilling speed increase considering the axial vibration of drill string

J Braz. Soc. Mech. Sci. Eng.

Wei

Dai

et al. 2020

Self Cite

Based on the existing research and combining with downhole conditions, this paper proposes a new type of downhole vibration tool to increase the rate of penetration (ROP), shorten the drilling and completion cycle and achieve more productive operations. As a whole, the axial vibration of the drill string is analyzed uniformly and the ROP is increased. A dynamic analysis model of the axial vibration of the drill string in the horizontal well is established. Based on the research on the working mechanism of the tool, this paper analyzes the flow area, pressure drop and axial force of the core valve system and determines the change law of the axial force. The field experiments verified the correctness of the established dynamic model method and the rationality of the tool and showed that the tool has a significant effect of increasing the ROP. The theoretical model established in this paper can improve the understanding of drill string dynamics. The proposed design method can provide ideas for the development of new drag reduction and speedup tools, and the calculation results can provide a reference for the determination and optimization of key parameters for drilling speedup.