## 2 Materials and Methods  
The soil identified in the vicinity of the oil wells within the study area was transported to the bioremediation pad area where the limiting parameters for physical and chemical properties are aimed to be achieved: a pH value in the range of 5.5-8.5, an optimum moisture value in the range 40-60%. The high value required for humidity derives from the water required for biochemical reactions. Water is the reaction medium for all biochemical processes in the bioremediation soil, so the soil beds on the bioremediation platforms are frequently sprayed with water from the platform lagoons. To map functional and environmentally friendly oil extraction wells, the legislative norms at the time of the rehabilitation works of oil extraction wells as well as the methodological norms of the Order No. 756 of 3 November 1997 (updated) [25] for the approval of the Regulation on Environmental Pollution Assessment and Law No. 74/2019 [26] on the management of potentially contaminated and contaminated sites will be used. The natural setting of the study area is represented by the territories in the North West of Romania, where there have been and still are oil exploration wells in the West of the country. These are mainly found in Bihor and Satu Mare counties (Figure 1). The number of operational wells identified for this study amounts to 695 operational wells (Figure 1). Digital mapping using Google Earth satellite imagery, direct field identification, and GPS point saving for the boreholes taken as case studies in the present paper were used for their mapping. From the analysis, it can be seen that 49.6% of the functional wells are located in the zone of brown-luvial soils (podzolite), 26.5% of the functional wells (184 wells) are located in the zone of alluvial soils, 69 of them in the zone of brown clayey-louvial soils, 67 wells on albic Luvisols (podzolite clay-louvial). Most wells are located on plots of land occupied by forest vegetation, with 133 functional wells, the most, 123 being brown-luvium (podzolite) soils. A large number of wells, 130 out of 695 studied, are located on plots classified as land occupied by buildings, yards and industrial areas, 91 of which are located on brown-luvium (podzolite) soils. In the category of arable land proper, 124 wells are classified, 72 of which are located on brown-luvial (podzolite) soils. The distribution of boreholes on these soil types and land use classes is important because once they are decommissioned, and the polluted soils are bioremediated, crop use recommendations can be made to make the most environmentally and economically efficient use of this land. Figure 1: Geographical position of the study area. For the classification of the soil profiles taken from the field into intervention classes, the threshold values of the TPH values according to Order 756/1997, and the reference values regulated by the same Order MAPPM Regulation on the assessment of environmental pollution for sensitive land use will be taken into account (Table 1). To determine the intermediate pollution values, 3D modeling based on interpolation using GIS technology using ArcMap 10.7.1 software will be used to obtain specific modeling of the TPH concentration values in the vicinity of the wells taken for analysis. Good results have been obtained for the decontamination of petroleum-contaminated soils using microorganisms because the biodegradation efficiency is induced by the adaptability of microbes using petroleum substances as energy and carbon sources to live in contaminated soils, the most efficient being indigenous microorganisms [27; 28; 29; 30; 31]. In the bioremediation platform, when the aim was to reduce moisture, the aeration method was used by mixing the soil with the BACKHUS aerator. As a chemical alternative, NPK was used with particular attention to pH modification.