## 4 Research Results and Discussion
To verify the solution and check whether the combined inversion process preserved the velocity distribution as defined in the initial model PVM, a simple comparison of interval velocities with the values extracted from models obtained through SRT and SJI was carried out. Additionally, the extracted curve from the initial model PVM was plotted on the panels. These comparisons are presented in Figure 9, showing the velocity distribution for two wells in the Raczyna deposit area [27]. The plots demonstrate relatively good agreement between the curves while maintaining the trends of vertical velocity variation. Particularly good agreement is observed at greater depths. Based on the models presented in Figure 7, PreSDM migrations were performed without MVA corrections, as the purpose of the described test was to verify the utility of the PVM models as initial models for the first iteration of MVA. Additionally, the suitability of these models as the main solutions for VID fields intended for PreSDM was verified. The conducted test demonstrated that the developed models (Figure 7) perform well in depth migration. Figure 10 presents the results of PreSDM for a section of seismic profile M-5 (Figure 1). An analysis of the quality of the obtained results was conducted based on the comparison of the seismic sections after PreSDM migration. At this stage of the work, the focus was on evaluating the seismic structural image, which is an important aspect of data processing that leads to the proper identification of the geological medium. Several studies carried out in this area allowed for the verification of the effectiveness of the applied velocity field validation methodology [7; 24; 25]. It should be emphasized that the data were recorded along a regional profile aimed at deep structural reconnaissance. Figure 9: Verification of the correctness of the velocity field correction was conducted at wells D-4 and R-8. The quality of the obtained seismic image is comparable to the results of processing along seismic lines where the acquisition parameters were designed to recognize the Jodlowka and Raczyna reservoir zones [27]. It is worth noting that this result was obtained in the first iteration of PreSDM. Figure 10: Results of PreSDM migration. (**A**)—Seismic sections after PreSDM calculated using the raw velocity model PVM. (**B**)—Seismic sections after PreSDM calculated using the velocity model obtained from refraction tomography for near and far offsets. (**C**)—Seismic sections after PreSDM calculated using the velocity model obtained from SJI of refraction and gravity data. The same PreSDM workflow was applied to all versions, with only the velocity model being changed. The projections of the nearest wells D-4 and R-8 were overlaid on the seismic sections. The obtained results indicate that the procedure of creating independent models for PreSDM, supported by the combined inversion of independent geophysical data, is a good tool for assisting seismic data processing. In Figure 10, Panel A shows the seismic sections created in the CDP domain from the seismic gathers after PreSDM, calculated using the basic velocity model PVM (Figure 7A). It exhibits the most consistent phase (signal) representation of reflections, mainly in the flysch part of the thrust zone, compared to the other sums (Figure 10B,C). However, the analysis of the seismic data quality for exploration purposes, specifically in the Jodlowka and Raczyna [27] reservoir zones (Figure 2), indicates that the structural image in this section is the weakest. This is particularly evident in the northern part of the section, where versions B and C (Figure 10) show continuity of horizons, while version A (Figure 10) shows them being scattered and difficult to interpret. These structures are associated with the Jodlowka and Raczyna reservoirs. The seismic sections presented in Panel B (Figure 10) provide a correct and comparable structural image compared to the production processing versions (Figure 2).