Abstract
Deep in situ rock mechanic is of great significance for deep foundation research and engineering application. In order to explore the deep in situ mechanical law, it is necessary to maintain the in situ environment, which means to achieve fidelity coring. However, at present, there is a lack of method of deep rocks with quality-preserving, moisture-preserving, and light-proof to obtain deep rock specimens, making it difficult to obtain in situ scientific information of the core. In this study, we developed a novel in situ quality-preserving coring method of deep rocks based on an in situ film-forming process. In this method, a solution was covered on the core, and then a sealing polymer film was formed through crosslinking reaction. Organic montmorillonite and carbon black functional fillers were incorporated to further reduce the O2 and water vapor permeability and light transmittance of the polymer sealing film. The sealing film was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Compared to the neat silicone rubber film, the O2 and water vapor permeability and light transmittance of the sealing film were reduced by 81.2%, 84.4%, and 100%, respectively. In addition, the mechanical and thermal stability of the sealing film was excellent; it showed an elongation at a break of 98.0% and a tensile strength of 0.857 MPa. Moreover, a simulator was developed and the sealing film showed an excellent quality-preserving ability on the rock specimens. The significant improvement demonstrated that the method developed in this research may open up new opportunities for the development of the in situ quality-preserving coring method of deep rocks and construction of deep in situ rock mechanics.
Highlights
With the shallow resources of the earth gradually exhausted and decreasing of conventional energy, deep exploration of energy has become necessity. [1]
We report a mechanism of in situ crosslinking and curing film-forming for deep in situ qualitypreserving, moisture-preserving, and light-proof coring of deep rocks
Ermal stability of Organic montmorillonite (OMMT) was investigated by thermogravimetry as shown in Figure 6. e water molecules in OMMT started to be lost above the room temperature, and there are no changes in structure of OMMT. e initial temperature of thermal degradation is at 225°C, and the alkyl chain of OMMT is decomposed completely at 460°C, which means that the OMMT can maintain the relatively stability under 225°C
Summary
With the shallow resources of the earth gradually exhausted and decreasing of conventional energy, deep exploration of energy has become necessity. [1]. Xie et al [18, 19] proposed a coring method and technology that preserved the quality and moisture of specimens and blocked the light of external by applying a polymer composite film with sealing effect of preventing the exchange of matter between the core and outside of the specimen. It is difficult to coat the core during the dynamic process in a narrow space of coring casing To solve this issue, a film-formation mechanism was developed by regulating the basic properties of the sealing film and controlling the film-formation process, where polymer composite material played a significant role in the qualitypreserving, moisture-preserving, and light-proof coring. Erefore, exploiting material-forming mechanisms appropriately, designing suitable film components, and improving their properties are important factors of using silicone rubber for deep in situ quality-preserving coring. We designed a quality-preserving coring simulator, and the quality-preservation effect of the core with the sealing film was verified
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
