Research Of Composite Technology And Application In Bored Sealiing

As a basic technical means for controlling gas, sealing has extensive application ranges in mine areas. In our country, however, the sealing quality of various drillings is unsatisfactory, which needs to research on sealing material, technology and equipment. To improve utilization ratio of sealing, accelerate elimination outburst rate of coal seam, reduce number of drilling and save production cost, the researches on sealing drilling with composite have very important realistic significance for the containment of serious accidents, such as gas outburst and gas explosion.The main results in this thesis are as follows:Firstly, we analyzed the distribution of stress field and fracture field around the drilling, deduced the expression formulas of fractured zone and plastic zone that around the drilling. Some conclusions were obtained from theoretical analysis and numerical simulation. Sealing rock fracture was formed around the drilling, based on the injected sealing grout spreads and fills the plastic zone by adscititious pressure or swelling pressure itself, which making the permeability and mechanical state change in the drilling to the plastic zone.Secondly, according to the permeation grouting theory with the spherical diffusion and cylindrical diffusion, the theoretical model of seepage and stress distribution around the drilling after sealing with fluid was deduced. The model describes the relations between permeability, stress in rock around the boreholes and parameters of different slurry.Thirdly, requiring by for micro-fissure sealing, the cement-based polymer composite was developed. . Moreover, the reaction mechanism of the cement-based polymer composite is expounded through researching on the interface theory of composite, expansion mechanism of cement, micro-encapsulation technology, reaction principle of controlling the spread and the process of sol transition.Fourthly, the types of target material and technological processes of experiments were established based on requirement of sealing material. The types and quantity of the raw material are determined owing to above researches. After the orthogonal experiments, three cement-based polymers composite were obtained - PD materials. The value of expansion coefficient about three materials is 1.29, 1.31, and 1.35, respectively. The tests of sealing negative pressure drilling character for PD-I material and tests of sealing high pressure drilling character for PD-III material saw a conclusion: The sealing performance of PD was better than polyurethane. The reason is explained that why the PD is denser, by analyzing and observing micro- structure of PD and polyurethane.In addition, the analysis indicates that the equipment should have some stress to overcome resistance of the fluid flowing. Furthermore, we developed the reciprocating plunger pumps with hydraulic booster system, including manual hydraulic injection pump, pneumatic hydraulic injection pump, double dynamical injection pump and the matched pneumatic mixer.Finally, according to the performances of sealing materials and grouting equipments, a kind of tamponade - grouting sealing process was developed and its key part - plugging slurry plug was designed. Meanwhile, we popularized the technology in Ping Dingshan mine areas with PD-II and used PD-III in Cui Miao mine, evaluated and analyzed the interrelated parameters, simultaneously.From the researches above, the essence of sealing drilling was obtained in theory aspect, the theoretical model of seepage and stress distribution around the drilling after sealing with fluid was deduced, while the cement-based polymer composite and the tamponade - grouting sealing process was developed. Meanwhile, the equipment to transport sealing material into drilling developed, too. The studies show that the new hole sealing technology has more superiority in the practical applications and the coming future.During the research, the authors published 6 papers, in which 2 were Search by EI; obtain or apply for the processing of 8 patents, 4 of which are invention patents; and won the second prize of a ministerial-level scientific research, ranking seventh.