# Measurement Method of Whole Mechanical Automatic Vertical Drilling Tools
###### Abstract  
The inaccurate positioning of a plat valve is a crucial factor affecting the efficiency and safety of drilling operations. Because of the complicated structure of vertical drilling, it is difficult to obtain the actual position of a plat valve during the working process. This work effectively addresses the challenge of accurately measuring the deflection angle of a plat valve in mechanical automatic vertical drilling. Initially, a comprehensive mathematical model was proposed for determining the angle range of the plat valve, which was founded on the thrust generated by vertical drilling. Furthermore, this work proposed a precise measurement methodology for acquiring the crucial parameters of the MVDT. The actual deviation angle range for the N-MVDT and O-MVDT vertical drilling was calculated using data obtained from measurements of the tools. At the same time, the influence of TID on the performance of the MVDT was determined. Then, a simulation was carried out to compare the calculation results. From this, it was determined that the deflection angle range of the O-MVDT at a higher rotational speed was [86\({}^{\circ}\), 58\({}^{\circ}\)], and the deflection angle range of the N-MVDT was [\(-14^{\circ}\), 14\({}^{\circ}\)]. By comparing the two methods, the error in the angle range was derived. The error of the N-MVDT was less than 16.67%, and the error of O-MVDT was less than 9.43%, proving that the measurement method and the mathematical model can accurately estimate the deflection angle range of a plat valve for mechanical automatic vertical drilling. The experimental and mathematical model results consistently showed that the deflection angle \(\varphi\) of the N-MVDT was significantly smaller than that of the O-MVDT, so the TID significantly improved the stability of the MVDT. vertical drilling tool; measuring method; mathematical model; stability analysis; deviation angle (c)2024 1  
Previous studies showed that friction is mainly caused by bearings and disc valves, and it was pointed out that the friction at the upper disc valve is the main factor affecting the accuracy of the eccentric system [16]. Because of the structure of drilling tools, \(\varphi\) cannot be eliminated, but it can be reduced. Based on the above problems, many scholars have studied the optimization of the plate valve based on the relationship between the deflection angle \(\varphi\) and the friction force of the plate valve. [PERSON] [17] developed a circular plate valve to replace traditional plate valves, which reduced the pressure of drilling fluid on the plate valve working surface, effectively reducing the friction resistance moment between plate valves and improving the sensitivity of drilling tool correction. [PERSON] [18] designed an optimized design scheme for a small-diameter plate valve with a guide groove. The new plate valve had a guide groove corresponding to the piston chamber flow channel of the push block, which significantly reduced the friction resistance moment between the plate valves and improved the correction performance of the tools. For a further reduction in the deflection angle, a new type of mechanical automatic vertical drilling tool (N-MVDT) was designed by a team at the China University of Geosciences [19], which differed from the traditional mechanical automatic vertical drilling tool (O-MVDT). The difference between the two tools is shown in Figure 2a. Although the N-MVDT has a similar working principle to the O-MVDT [20], it is equipped with a torque-increasing device (TID) internally, which can be used in a closed-loop manner to more effectively reduce and improve the deviation control accuracy of drilling tools. To further understand the performance of the vertical drill, later generations of researchers verified the degree of reduction in the plate value of the above three design patents in engineering practice. [PERSON] et al.