Experimental and Numerical Study on a Two-stage Coring Method for Stress Measurement: Application to Deep and High-Temperature Geothermal Wells

We discuss the possibility of recording state in-situ stress in shape a rock core that is sampled using modified drilling method. This concept based on phenomenon cylindrical rock-core expands radially into slightly elliptical along its transverse cross-section when sample relieved anisotropic by drilling. The magnitudes and orientation stresses can, principle, be estimated from circumferential variation expansion. However, it not possible to evaluate expansion collected conventional way, with single bit, since will expanded extracted lacks information about required pre-expansion dimensions. To overcome this problem, we propose an innovative way referred as Dual-bit Coring. approach results has two signature cross-sections: first resulting second records initial circular prior Then, amount can differences between shapes those cross-sections. practical tool for carrying out Dual-bits works mechanically does require any electric devices sensitive high temperatures so expected function even deep temperature rocks at geothermal fields, such encountered supercritical systems.