# Measurement Method of Whole Mechanical Automatic Vertical Drilling Tools
## 2 Methods
### Measurement Experiment
#### 2.4.2 Experimental Method and Process  
In the experimental measurement in this paper, the inclination angle pump pressures and rotational speeds affect F\({}_{\text{i}}\) and \(\varphi_{\text{s}}\). The experimental parameters were selected as the well inclination angle (\(\delta\)), pump pressure (\(P\)), and rotational speed of the shell (n), which were used to determine the most favorable parameters for the experiment and subsequent analysis. The influence of the three variables on the drilling performance of automatic vertical drilling were also determined. The effectiveness of the O-MVDT and the N-MVDT were evaluated using F\({}_{\text{i}}\). The parameter values are shown in Table 3.  
Because of the unsatisfactory reduced deviation control effect of the N-MVDT when \(\delta\) is low (\(\delta<1\)), the main focus of this paper was on the degree of performance improvement in the MVDT by the TID. The range of delta in this experiment was limited to 1-5\({}^{\circ}\). The weight on the bit was selected as 0.5-1.5 MPa, according to the actual working condition.  
Because of the large volume of data, the reliability of the experiment was validated using a subset of the data. This is a commonly used metric in practical applications since it is affected by both the pressure difference between the two sides of the steering ribs (\(\Delta\text{p}_{\text{i}}\)) and the effective contact area of the steering ribs.  
\[\overline{F_{i}}=s\Delta\overline{p}_{i} \tag{13}\]  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameters** & **Range/Value** \\ \hline Drilling inclination angle (\({}^{\circ}\)) & 0–15 \\ Pump pressure (MPa) & 0–1.5 \\ Motor speed (rpm) & 0–300 \\ Thrust force (N) & 0–20,000 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Design parameters of the experimental rig stand.  
Figure 11: The relative position and number of each steering rib and sensor.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameters** & **Value** & **Total Data Group** & **Evaluation Indicator** \\ \hline \(\delta\) (\({}^{\circ}\)) & 0; 1; 2; 3; 5 & \(2\times 5\times 3\times 2\) \\ \(P\) (Mpa) & 0.5; 1; 1.5 & \(2\times 5\times 3\times 2\) \\ \(n\) (rpm) & 90; 120 & =60 & \(F_{\text{i}}\) (N) \\ \hline \hline \end{tabular}
\end{table}
Table 3: Experimental operating parameters of the two prototypes.  
2.4.3. Reliability of the Experiment  
This experiment was designed to be conducted above ground, following the testing standards and operational procedures outlined [29]. As there was no wellbore or rock present, the vibrations caused by the steering ribs pushing against the wellbore and the cutting of the rock by the drill bit affected the experiment. Additionally, as the sensors and steering ribs were fixed, the influence of the pushing angle of the steering ribs on the pushing force was ignored.  
It should be noted that there may be experimental errors due to the absence of rock debris in the circulating fluid medium and the inability of the above-ground experimental environment to simulate the effect of temperature on fluid flow as it exists in the downhole. Moreover, experimental errors can also arise from the rusting of parts that are exposed to the fluid environment.  
Since \(\overline{F_{i}}\) varies with time, in order to study the variation in \(\overline{F_{i}}\) more clearly, we defined \(\overline{F_{i}}\) as the average value of \(\overline{F_{i}}\). \(\overline{F_{i}}\) represents the equivalent pushing force that can be generated by each steering rib against the well wall.