China
Africa
Explore chapters and articles related to this topic
Offshore Drilling and Completion
Published in Shashi Shekhar Prasad Singh, Jatin R. Agarwal, Nag Mani, Offshore Operations and Engineering, 2019
Shashi Shekhar Prasad Singh, Jatin R. Agarwal, Nag Mani
These include bottom hole assembly (BHA) configuration/directional response; drill string – length, size, weight, grade, connection; performance properties – tension, torque, buckling; operating procedures – torque and drag, percent rotary mode, tortuosity, casing wear prediction/mitigation plan, inspection procedures/frequency.
Decentralized Overlapping Control Design with Application to Rotary Drilling System
Published in IETE Journal of Research, 2023
M. Z. Doghmane, M. Kidouche, A. Ahriche
In this study, the parameters of the model have been taken from operational rotary drilling system of oil exploration field [5]. The rotating part of drilling system is composed essentially of driving motor (top drive), drill string, including thin-walled pipe section, and BHA that contains heavy thick-walled collars and bit attached at the bottom end of the drill string (Figure 1(a)). In order to centralize the bit, many stabilizers are placed at the collar section; they increase the buckling load-carrying capacity of the collar section, and they are used to control well trajectories for directional drilling [27]. The drilling mud circulates in the annulus between the BHA and borehole; it raises cuttings to the surface, keeps pore fluid in their places, in addition to maintaining wall stability and cooling the bit.
Investigation of the mitigation effect of an anti-stall tool on stick-slip vibrations of drill strings
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Tong Cao, Kaian Yu, Hongwu Zhu, Xuyue Chen
A schematic diagram of the AST is shown in Figure 3. The tool consists of two movable parts: the upper part, which is connected to the drill pipes, and the lower part, which is connected to the BHA and the drill bit. These two parts of the tool are restrained by a screw pair and an axial spring. The AST working principle is illustrated in Figure 4 and can be explained as follows: During the process of normal drilling without stick-slip vibration, the AST works like normal drill pipes to transfer the WOB and torque on bit, and the axial force provided by the AST axial spring is converted to torque by the screw pair. When the rock breaking resistance suddenly increases and the torque (M1 in Figure 4) cannot drive the bit to rotate, the mitigating stick-slip function of the AST is activated, and the resistance torque from rock cutting overcomes the compressed spring to force the upper tool body to rotate with the helical spline. Therefore the tool telescopically contracts (S), the DOC and rock cutting resistance are reduced, stable rotation of the bit is ensured and stick-slip vibration is avoided.