Research On Grouting Performances And Hydration Synergy Effect Of Silicate-sulphoaluminate Compound System

Borehole leakage which is one of the most common and the most difficult engineering technical problems severely restricts the development of geological exploration. Being as a type of traditional grouting materials, cement is widely used in geological drilling plugging, which also has advantages of convenient use, favorable perfusion, adjustable performances, durability and environmental protection. Therefore, carrying on a research about novel cement-based grouting materials which are able to meet performance requirements in complex formation drilling may provide theoretical basis and scientific evidence for solving the engineering technical problem of borehole leakage in complex stratigraphic drilling and promote important research value and practical significance of promoting geological drilling technology.Portland cement and Sulphoaluminate cement are two kinds of inorganic cementations materials widely used in geological exploration drilling plugging. However, because of disadvantages of Portland cement, such as poor stability, long setting time, low early strength, and easy to be diluted by groundwater in the hole, the plugging effect is often not ideal. Sulphoaluminate cement has the advantages of rapid hardening, early strength, frost resistance and impermeability performance. However due to the setting speed, the viscosity characteristics can not be well controlled, therefore it often can not achieve the ideal perfusion plugging effect, besides the cost is too high.In order to overcome the weakness of inorganic cementing materials in the aspects of drilling plugging, domestic and foreign experts and scholars have made a large amount of exploration and research. Compounding is an effective way to improve the performance of cement perfusion. Research shows that the Portland cement and Sulphoaluminate cement composite slurry has a unique hydration synergistic effect, it has excellent hydration condensation characteristics, such as the hydration and setting speed, right angle thickening, initial and final setting time interval short and so on. Therefore, carrying out the research of Portland-Sulphoalminate composite perfusion properties and hydration of synergistic effect, it is expected to provide a new way to solve the problem of drilling and plugging technology in the complex stratigraphic of loose and broken, steep and wide cracks.In the paper, Grouting performances of Portland cement and sulphoaluminate cement were firstly tested, then appropriate additives were used for modifying treatment respectively, preparing for the study of the compound slurry. The paper focuses on the grouting performances of different mixture of Silicate-Sulphoaluminate compound cement, and using the orthogonal test to determine the Silicate-Sulphoaluminate compound cement grout formula which is satisfied with the leakage blocking engineering problems.In order to explore the hydration synergy effect of the Silicate-Sulphoaluminate compound cement further, the digital measuring system of cement hydration heat was used to analyze the hydration heat release rate of the compound cement system, which contributes to revealing the hydration of the compound cement system different from Portland cement or sulphoaluminate cement. Combining with scanning electron microscope(SEM) and X ray diffraction(XRD) and other advanced test instruments,the characteristics of the micro fabric of compound cement system was studied, the unique hydration synergy effect of the Silicate-Sulphoaluminate compound cement was further explored.In the end, combining typical complex leakage formation of the Yangshan mining, the optimized formulation of the silicate-sulphoalminate composite slurry was used for on-site drilling plugging and the preliminary application results have been achieved, which accumulates valuable experience for further drilling plugging application of the compound slurry of the Silicate-Sulphoaluminate system.The research results have important guidance and reference significance to further improve and perfect silicate-sulphoalminate composite system perfusion properties of cement.