## 3 Methods
### Instrument Parameter Test
When the concentration exceeded 100 ppm, the RSD value tended to be stable, corresponding to less than 3%. Additionally, we also compared the deviation of single measurement values from the average value for each concentration, and the results are shown in Figure 7. It can be seen in the figure that when the standard gas concentrations were 11.5 ppm and 20 ppm, the error of the single measurements could be more than 10%,  
Figure 5: Instrument blank and interference peak signal diagram. Figure 6: Helium concentration standard curve. and the deviation was large. However, with the increase in the concentration, the error of the single measurements tended to stabilize, approaching 3%. Through the above analysis, we found that the error of the instrument was relatively large at low concentrations and small at high concentrations. Therefore, during field detection, when low helium concentrations are detected, the scanning interval (usually 1 min) can be appropriately reduced to obtain more data and ensure their reliability; this problem does not exist at high concentrations. Furthermore, during the laboratory test, we found that the instrument produced signal attenuation during long-term continuous measurements. Considering that the instrument needs to continuously detect the helium concentration in the mud gas for a long time during field measurements, it is necessary to measure the attenuation coefficient of the instrument to regress the error caused by signal attenuation. In this paper, a helium standard sample with a concentration of 85 ppm was used for continuous measurement testing for 57 h, and the results are shown in Figure 8. It can be seen in the figure that as time increased, the signal gradually decreased, showing a downward trend overall. By fitting the data \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Conc** & **11.5** & **20** & **40** & **60** & **80** & **100** & **200** & **300** & **400** & **500** \\ \hline  & 216.06 & 489.87 & 1113.44 & 1655.32 & 2227.78 & 2717.81 & 5452.34 & 8128.76 & 10,214.36 & 12,526.37 \\  & 206.94 & 487.52 & 1119.00 & 1718.25 & 2231.40 & 2688.56 & 5489.84 & 8011.93 & 10,496.63 & 12,576.73 \\  & 204.70 & 457.73 & 1029.81 & 1667.75 & 2303.24 & 2739.66 & 5476.91 & 8001.17 & 10,161.67 & 13,143.76 \\  & 212.84 & 488.04 & 1111.86 & 1694.24 & 2170.98 & 2799.83 & 5516.29 & 8029.04 & 10,560.70 & 13,113.57 \\  & 185.18 & 456.76 & 1017.85 & 1503.53 & 2323.41 & 2882.53 & 5388.67 & 8112.97 & 10,586.12 & 13,102.60 \\  & 187.14 & 451.80 & 1043.91 & 1693.03 & 2371.86 & 2708.83 & 5524.52 & 8204.97 & 10,751.64 & 13,173.48 \\  & 205.48 & 483.45 & 1070.14 & 1699.05 & 2349.79 & 2845.90 & 5396.38 & 8191.51 & 10,399.08 & 13,022.04 \\  & 205.15 & 502.19 & 1051.76 & 1677.83 & 2310.09 & 2787.58 & 5766.08 & 8205.77 & 10,571.15 & 13,243.08 \\  & 178.84 & 481.67 & 1070.56 & 1719.30 & 2315.90 & 2859.42 & 5511.45 & 8210.38 & 10,502.72 & 13,010.30 \\  & 203.18 & 511.61 & 1085.95 & 1687.23 & 2322.80 & 2838.35 & 5396.49 & 8263.57 & 10,648.68 & 13,069.48 \\ STDEV & 11.79 & 18.83 & 34.09 & 59.15 & 59.26 & 65.93 & 103.87 & 89.50 & 175.13 & 232.84 \\ AVERAGE & 200.55 & 481.06 & 1071.43 & 1671.55 & 2292.73 & 2786.85 & 5491.90 & 8136.01 & 10,489.28 & 12,998.14 \\ RSD & 5.88 & 3.91 & 3.18 & 3.54 & 2.58 & 2.37 & 1.89 & 1.10 & 1.67 & 1.79 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Test data of helium standard samples at various concentrations. Figure 7: Single measurement deviation analysis. points, we found that the signal value and the time showed a good linear relationship, and the R-square of the equation was 0.93925, which is highly acceptable. The helium detector can be successful deployed at drilling sites, as it can measure all day automatically and uninterruptedly without manual operation; it is only necessary to test the attenuation coefficient of the instrument once a day, which is used to calibrate the helium concentration.