The drilling solution components’ impact on the environment and directions of its reduction

The problem of the oil wells operation influence on the environmental ecological state is considered. The technical and biological aspects of the impact of drilling solution components used in the process of oil production on the biotic and abiotic environment are analyzed. The methods of preserving the cleanliness of reservoirs and soil during the wells operations and preventing pollutants from entering the environment are described. Possible effects of the toxic compounds of the drilling fluid on living organisms, in particular plants, have been identified. The components of drilling fluids of different types are characterized by different levels of environmental hazard. The lowest level of threat to environmental safety is inherent in the clay type of solution, and the polymer-potassium solution is characterized by the highest potentially dangerous impact on the biota. Despite belonging to the third class of moderately hazardous substances, sodium salts, calcium and chlorides, as components of drilling fluids, have the highest destructive effects on the environment. Soil salinization has the most detrimental effect on plants, as it breaks the osmotic equilibrium in the soil-plant system, disrupts the transport of organogenic elements throughout the plant, and reduces the availability of moisture and minerals. Increasing soil pH due to the ingress of calcium and sodium hydroxides as components of drilling fluids adversely affects plant growth and development. Stability of some groups of plants to the influence of components of drilling fluids and ability of phytoobjects to resist stress influence are noted. Halophytes are well adapted to the growth in conditions of excessive soil salinization due to the specific metabolic and structural features of the organization. Low oil content in drilling fluids can be released into the environment and, when accumulated in the aquatic and soil environments, lead to a number of destructive processes in living systems. Plants sensitive to oil pollution respond by reducing growth processes, increasing catabolic processes, and reducing assimilation function. In order to minimize the negative impact of chemicals on the environment of oil production territories, it is necessary to apply a comprehensive approach that combines the technical aspects of pollution control with effective biological methods. The urgent task of modern environmental science is to search for oil-resistant plant species that are effectively capable of converting toxic petroleum products to biota-safe compounds. Technological recommendations for the prevention of environmental pollution by drilling fluids are proposed, as well as phytorecultivation methods for controlling already polluted ecosystems.

Mining-Induced Time-Series Deformation Investigation Based on SBAS-InSAR Technique: A Case Study of Drilling Water Solution Rock Salt Mine

Compared to traditional coal mines, the mining-induced dynamic deformation of drilling solution mining activities may result in even more serious damage to surface buildings and infrastructures due to the different exploitation mode. Therefore, long-term dynamic monitoring and analysis of rock salt mines is extremely important for preventing potential geological damages. In this work, the small baseline subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technique with Sentinel−1A imagery is utilized to monitor the ground surface deformation of a rock salt mining area. The time-series analysis is carried out to obtain the spatial–temporal characteristics of land subsidence caused by drilling solution mining activities. A typical rock salt mine in Changde, China is selected as the test site. Twenty-four scenes of Sentinel−1A image data acquired from June 2015 to January 2017 are used to obtain the time-series subsidence of the test mine. The temporal–spatial evolution of the derived settlement funnels is revealed. The time-series deformation on typical feature points has been analyzed. Experimental results show that the obtained drilling solution mining-induced subsidence has a spatial characteristic of multiplied peaks along the transversal direction. Temporally, the large-scale surface settlement for the rock salt mine area begins to appear in September 2016, with a time lag of 8 months, and shows an obvious seasonal fluctuation. The maximum cumulative subsidence is detected up to 199 mm. These subsiding characteristics are consistent with the connected groove mining method used in drilling water solution mines. To evaluate the reliability of the results, the SBAS-derived results are compared with the field-leveling measurements. The estimated root mean square error (RMSE) of ±11 mm indicates a high consistency.