Fracture structure characteristics are crucial for determining the fracture mechanism of coal mass and the migration law of oil and gas disasters. In this study, computed tomography (CT) scanning technology and fractal theory were used to investigate the damage process of coal mass in the common storage area of coal and oil resources under uniaxial compression as well as the degree of damage of high-pressure oil and gas diffusion to the surrounding coal and rock mass. Uniaxial compression and acoustic emission signal acquisition tests of coal mass were conducted. The relationship among the load evolution law of coal samples at different positions around the oil well and the failure mode of key failure positions were further analyzed. Finally, the formation mechanism of coal load fracture and oil and gas disaster channel in coal and oil resource costorage area was investigated. The test results showed the following: (1) High-pressure oil and gas diffusion degrades the mechanical properties of coal mass in varying degrees. The closer the coal sample to the oil well, the greater the fracture development degree, the fracture density, the fracture fractal dimension of coal sample, and the severity of the coal mass damage and the lower the compressive strength, the acoustic emission event number, and the cumulative energy. (2) The lateral diffusion of high-pressure oil and gas changes the failure mode of coal samples in the common storage area of coal and oil resources. The failure modes when the sampling location is away from the oil well are step failure, conjugate shrinkage failure, and high-frequency vibration intermittent microcrack fracture. (3) Coal mass instability and coal mine oil and gas disaster in the common storage area of coal and oil resources can easily be induced by the formation of microfracture expansion, extension, and coalescence caused by coal failure, the formation of network and macrochannels of main fracture, and the instantaneous release of accumulated stress during failure.

The dynamic evolution characteristics of fracture are crucial to analyzing the development of coal and rock mass instability, gas diffusion law, and dynamic disaster prediction. These characteristics affect coal rock fractures and gas-induced disaster channels. Based on the experimental results, we found the following: In areas rich in both coal and oil, the coal mass damage due to high-pressure oil diffusion was inversely correlated with the distance of the coal mass from the disaster source. Moreover, as the coal mass became closer to the disaster source in the abandoned oil well, the average CT number reduced, mechanical performance diminished, fracture volume ratio increased, and capacity of the oil and gas storage improved. The four-dimensional analysis of the rock evolution and strength grade showed that coal mass stress, fracture propagation, and AE incidents were characterized by a low-strength compression stage featured by tensile fractures, medium-strength elastic stage with shear fractures replacing tensile fractures, and high-strength rapid fracture stage with rapid growth in shear fracture quantity and intensity. The dynamic conversion between coal mass instability disaster in coal and oil resources co-storage areas and oil and gas disaster was clarified. We propose high strength, high RA, and low AF of AE incidents in the rapid fracturing stage as the qualitative warning factors for the fracture of coal mass and the occurrence of oil and gas disaster.

The reservoir gas disaster has distinct characteristics and is a key factor that threatens the safe and green mining of coal mines in the costorage area of coal and petroleum resources. In order to solve the problem of prevention and control of reservoir gas disasters in coal mines, the characteristics of oil-bed gas disasters in abandoned oil wells in coal mines were analyzed, and the oil-bed gas disaster mechanism of abandoned oil wells without isolation coal pillars was revealed to study the scope of gas disasters around oil wells under the influence of production. The research shows that: (1) abandoned oil well reservoir gas disasters have the characteristics of high gas pressure, high concentration, large lateral influence area, wide vertical sweep range, and frequent disasters, which seriously threaten the safety and green mining of coal mines; (2) divide the reservoir gas disaster of abandoned oil wells into the high-pressure gas disaster in the well and the disaster in the surrounding oil-bed gas enrichment area; (3) according to the numerical simulation results that the maximum damage depth of the coal seam mining floor is 38.6 m and the seepage height of high-pressure oil-bed gas is 40 m, the safety factor k is introduced, and the reservoir gas sweeping range of the abandoned oil well is determined to be 95.4 m below the coal seam to the surface; (4) the comprehensive prevention and control technical scheme of oil-bed gas for controlling high-pressure oil-bed gas in wells by ground plugging and downhole injection and injection of diluent to control enriched areas was proposed, which successfully solved the problem of safe and efficient exploitation of Shuangma coal mine in Ningdong coalfield by abandoned oil wells. The research results provide effective solutions for the realization of green mining in many coal mines in the costorage area of coal and oil resources in China and have important application value for the prevention and control of dynamic disasters in the costorage area of resources.

In order to research the creep deformation characteristics of frozen soil and the effect of various influencing factors on creep, indoor uniaxial creep tests were carried out on frozen soil specimens at temperatures of −5, −4, −3 and −2 °C under loads of 0.25, 0.5, and 0.75 σt, respectively. The creep deformation characteristics of frozen soil under different temperatures and load conditions are analyzed under unconfined conditions. The results show that under the uniaxial creep test conditions, when the load is low, there is no accelerated creep stage in the creep curve, which belongs to the decaying type creep; when the load is 0.75 σt, the creep curve enters the stage of accelerated creep, and the creep turns non-attenuated; temperature is the most important external factor affecting permafrost soil creep, and the proportion of ice is the key internal factor for affecting permafrost soil creep, the temperature is negatively correlated with the proportion of ice and the sensitivity of creep rate to temperature and load increases with the decrease of the proportion of ice; the damage variable D is introduced to modify the creep constitutive equation of the frozen soil, the creep process of frozen soil is well described by the modified creep constitutive equation for frozen soil.