The article is aimed at quantitatively assessing the effectiveness of digital monitoring of soil and water conditions during drilling and operation of wells, and identifying the stable relationship between the level of digitalization of environmental control and optimization of environmental protection costs in oil and gas enterprises. The empirical base includes data from 12 companies of the Ural and Western Siberian regions for 2015–2023, consolidated across more than 40 indicators and covering investments in IIoT, remote sensing, UAVs, and predictive analytics, as well as logs of incidents, fines, payments for environmental impact, and reclamation costs. The methodological approach combines system and comparative analysis, Pearson and Spearman correlation tests, paired and multiple regression with validation by t and F criteria, ensuring rigorous statistical reliability. A strong inverse relationship is established between investments and incident frequency: an increase in investment from 8.43 to 55.37 thousand rubles per well is accompanied by a decrease in incidents from 2.17 to 0.49 cases per 100 wells, with a correlation coefficient of -0.978. The paired regression shows that each additional 10 thousand rubles per well is associated with a reduction in incident frequency by 0.35–0.40 per 100 wells, confirming the preventive effect of digital systems. In response scenarios, digital monitoring reduces the average detection time of a leak from 18.7 to 1.2 hours, decreases the average spill volume from 8.34 to 1.12 m³, and lowers the cost of eliminating the consequences of one incident from 12.65 to 2.48 million rubles, demonstrating a nonlinear dependence of damage on detection delay. A structural transformation of expenses is revealed: the share of preventive spending and ongoing control among digitalization leaders reaches 41.9%, while the share of fines decreases to 8.7% and post-incident remediation costs to 15.3%. The economic assessment shows a negative net effect in the first year of active investment (ROI −14.80% in 2018), followed by sustained profitability growth to 66.65% in 2023, with a net annual effect of 442.8 million rubles across the group of enterprises. Multiple regression with and a standardized beta coefficient of -0.72 for digitalization investments confirms their dominant contribution: a 1% increase in investments reduces total environmental protection costs in the next period by 0.58–0.65%, all other factors being equal. The scientific novelty lies in the formalization of cost elasticity to digitalization and in the integration of field incident metrics with financial indicators, while the practical significance is in providing an evidence base for investment decisions and regulatory incentives. Limitations are related to the non-public nature of some corporate data and regional specifics; prospects include differentiation by platform type and consideration of intangible effects (reputation, social license).