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Simulating the load torque of rotary valve in MWD with magnetic powder brake
Published in Artde Donald Kin-Tak Lam, Stephen D. Prior, Siu-Tsen Shen, Sheng-Joue Young, Liang-Wen Ji, Innovation in Design, Communication and Engineering, 2020
Long Wang, Yue Shen, Jia Jia, Yan Ling, Ling-tan Zhang, Ling-zhi Wei
The rotary valve is part of the MWD tools and is mounted inside the drill collar at the top of the drill bit. It consists of a stator and a rotor that moves relatively to the stator. The rotor is driven by the motor with a reducer [7]. Studies have shown that the load torque varies with the rotation angle in a non-monotonic complex law [8], and its calculation model can be expressed as a polynomial function of the rotation angle Mr(θ)=b+ρQ2(a0+a1θ+a2θ2+L+amθm)
Offshore Drilling
Published in Sukumar Laik, Offshore Petroleum Drilling and Production, 2018
A drill bit which actually cuts the rock is attached to the lower end of the drill collar. In the rotary system of drilling, a hole is made by lowering the string of the drill pipe and drill collars until the bit touches or approaches the bottom of the hole. Circulation of drilling fluid is established down through the drill pipe, and the fluid is discharged through ports or nozzles in the bit so that the bit and bottom of the hole will be kept clean. Rotation of the drill string is established by means of the rotary table. The top of the drill string is then gently lowered by means of the draw works or hoist until suitable weight for drilling is applied to the bit.
Discussion on long open-hole sidetracking technology based on an ultra-deep well in the Northern Tarim Basin
Published in Ahmad Safuan Bin A Rashid, Junwen Zhang, Advances in Mineral Resources, Geotechnology and Geological Exploration, 2023
Xin Qiao, Renmin Zhang, Cong Xiong, Jintao Wu, Dabin Fan, Fangyi Xu
The third round of drilling increases the rigidity of the sidetrack drill and adds a 159 mm drill collar. The drill tool combination is based on a 215.9 mm roller cone bit, a 172 mm straight screw, and a 2.5° elbow joint, and then three 159 mm drill collars are added. Time-controlled drilling is adopted, sidetracking at 3 h/m, the tool face is placed at 90–120°, the support pressure is still serious, the maximum support pressure is 14 t, and the maximum lifting force is 35 t. When the sidetracking reached 7135 m, it was decided to trip out due to the time of use of the roller cone bit. In order to solve the problem of supporting pressure in the fourth drilling trip, an attempt was made to connect a hydraulic oscillator to the drilling tool assembly. The drilling tool assembly is a 165 mm hydraulic oscillator based on the 215.9 mm hybrid drill bit, 172 mm straight screw, and 2.5° elbow joint. During the time-controlled sidetracking process, the support pressure is still serious. Glass microbeads (0.3%) are added to the well slurry. The support pressure has been significantly improved, but the cost of glass beads is high, and it is not continuously replenished. After a period of time, the support pressure situation is serious, and drilling reaches 7144 m. The sand samples are lumps and cement, the inclination data are consistent with the old wellbore, and it is judged that the drill bit is in the old wellbore. Then, we trip out to re-run the well and handle drilling fluid performance. On the basis of the fourth trip, the drilling tool assembly of the fifth trip removed the hydraulic oscillator and added a 206 mm stabilizer to further enhance the lateral force. In order to solve the problem of supporting pressure in this drilling, the well team installed torsion pendulum software in the top drive and cooperated with the torsion pendulum when sidetracking. However, this measure still failed to solve the supporting pressure problem, and the sidetracking was stopped when drilling to 7153 m.
Decentralized Overlapping Control Design with Application to Rotary Drilling System
Published in IETE Journal of Research, 2023
M. Z. Doghmane, M. Kidouche, A. Ahriche
One of the most used models for rotary drilling system is mass-spring-damper model, wherein the behavior of drill pipes is reproduced by a torsional spring, and the drill collar is represented by a rigid body (Figure 1(b)). The inertial masses, locally damped by and , are connected to each other by a linear spring with torsional stiffness and torsional damping [28]. The equation of motion is described by an ordinary differential Equation (1). and are the angular displacements of the top drive and the BHA, respectively. The angular velocity of the top drive is considered as the input signal ; it is proportional to top drive torque. The transmission box usage is to adjust the angular velocity ; the frictional torque represents, in this study, the torque on bit combined with the nonlinear frictional forces along the drill collars [29]. By setting , and , Equation (1) is written as
Near-bit apparent resistivity measurement method based on SPWM excitation
Published in Petroleum Science and Technology, 2023
Xingming Pan, Qian Shi, Haibo Zhang, Chen Wang, Yuzhe Tang, Jiran Li
When resistivity measurement is performed during drilling, the alternating excitation current is supplied to the transmitting coil, and an alternating electromotive force (EMF) is induced in the drill collar, which is the secondaries of the transformer, and this induced electromotive force (EMF) forms an induced current through the circuit composed of the drill collar and the stratum. The induced current from the transmitting coil to the bit can be divided into two parts: the current flowing on the drill collar between the receiving coil and the transmitting coil is called the focusing current, and the induced current flowing between the receiving coil and the drill bit is called the measuring current. Under the excitation of the measuring current, an EMF proportional to the measuring current is generated in the receiving coil. The EMF measured in the receiving coil is related to the induced EMF excited by the transmitting coil on the drill collar and the resistivity of the downhole medium (mainly the formation) adjacent to the drill bit (Kang, Ke, and Li 2017).
Abrasive Wear Behaviors of 4145H Drilling Tool Steel in Water-Based Slurries of Different Sands
Published in Tribology Transactions, 2021
Hong Cai, Yu Wang, Zhijian Peng
4145H steel is an internationally generally used petroleum drill collar steel certified by the AISI (American Iron and Steel Institute) standard and API Spec7 (American Petroleum Institute) that is mainly manufactured into the outer casing of oil extraction sucker pipes working underground at a depth of 3,000 m. It has been widely applied in the oil and gas industry due to its high strength, high hardness, and high resistance to torsion, bending, and abrasion. Therefore, many researchers have performed fundamental and application research studies. For example, Guo et al. (1) investigated the addition effects of cerium on the microstructure, hardness, and impact properties of 4145H drill collar steel at room temperature. Li et al. (2) adopted a laser quenching process to thermally strengthen 4145H drill tool steel, reporting the optimal parameters of the manufacturing process. Most research on 4145H steel has focused on modifying its properties, such as impact toughness, by the addition of trace elements, surface treatment, and so on (1, 2). However, no report has examined the wear performance and mechanism of 4145H steel during its applications in oil drilling although severe abrasion will result.