## 3 Results
Appropriate WOB values can lead to penetration rate increase without overloading the drill bit or drilling related machinery. In this sense, Table 14 suggests a safe minimum WOB for each RPM and FLOW combination exceeding these values, STICKRATIO may rise, which is not desired. Thus, WOB also has to be considered a limiting drilling mechanic parameter factor in the drilling process and in drilling optimization runs. Ideal operational conditions typically combine high RPM and high FLOW, resulting in an excellent STICKRATIO (green zone) but with WOB less than 13 [tf]. This combination guarantees reducing torsional vibrations and therefore reducing stick-slip as well. Critical drilling conditions arise with low RPM, low FLOW, and high WOB (above 13 [tf]), as these are more prone to lead to severe STICKRATIO (red), indicating a higher risk of operational issues due to increased undesired events. It is crucial to recognize that the decision matrix is not absolute because operational parameters can be constrained by specific tools. These limitations relate not only to the choice of ideal parameters for better performance but also to the constraints of downhole tools used in particular operations, such as LWD, MWD, RSS, PDMs, turbines, and specifications determined in the drilling programs, among others [7]. It is important to emphasize that extreme RPM, WOB and FLOW conditions should be avoided and used only in specific situations. For example, high RPM should be avoided in abrasive formations to prevent rapid abrasive thermal wear. In addition, high RPM should be avoided if the bit exhibits a \"whirl\" phenomenon (irregular rotational movement). Attention should be paid to certain speeds, as they can induce resonance in the drill string. High RPM in hard formations can reduce the rate of penetration (ROP), due to the difficulty that the inserts encounter when penetrating the formation. Furthermore, the rotational speed can be limited by restrictions of the drill pipe or the drive system. As for WOB, as the bit wears, it is necessary to apply more weight to maintain the same penetration rate in homogeneous formations. In general, WOB should be applied before the RPM reaches high values, ensuring that the cutting structure maintains an adequate cutting depth, stabilizing the drill bit and preventing the \"whirl\" phenomenon. Regarding FLOW, a high flow rate provides better hole cleaning, as it removes debris more efficiently due to high speed and HSI (High Speed Injection). However, excessive HSI can result in poor hole quality due to washout (hole erosion). Therefore, the flow rate should be compatible with the Junk Slot Area (JSA) to prevent bit erosion, especially in rock bits and steel body PDC bits [46]. Understanding the torsional vibrations and the MSE associated with the drilling process is crucial for optimizing drilling operations and minimizing operational costs. When these variables are described in detail and properly analyzed, they can provide valuable insights for the operator, allowing for the prediction and mitigation of adverse conditions that could result in significant costs. Studies indicate that the losses associated with these conditions can exceed $1 million per day [47]. Therefore, downtime and maintenance periods required during drilling activities become critical factors that impact not only operational efficiency but also the economic viability of drilling. Thus, rigorous analysis of vibrations and MSE is essential for implementing more efficient and safe drilling strategies, contributing to cost reduction and maximizing results during drilling operations.