These include identifying the rock ahead of the drill bit, evaluating the effect of the drilling tools on the rock, and optimizing jet parameters.
Identifying and evaluating rock ahead of the drill bit
Identifying and evaluating rock ahead of the drill bit to enhance the drilling speed in rock formation requires sophisticated sensing and guidance. An ideal smart drilling system automatically recognizes resistance and adjusts contact pressure to achieve desired rates of penetration.
Identifying and evaluating rock ahead of a drill bit can improve a drilling operation and minimize mining costs. It can also help determine the optimal location of a casing shoe.
Several embodiments of the invention include a downhole sensor subassembly that is connected to a drill bit. The subassembly receives raw acoustic sensor data and transforms it into a frequency domain. The data is then pushed to a surface computer that uses acoustic characteristics to evaluate the properties of the rock. The resulting data is then used to classify the formation and guide the bit in real-time.
The acoustic characteristics of the rock include normalized deviation of amplitude, apparent power and mean frequency. The acoustic properties can be used to determine the formation boundary and optimal position of a casing shoe.
Understanding the interaction of cutting tools with the rock
During the machining process, cutting tools interact with rock formations to enhance drilling speed and durability. Several studies have investigated the operational behavior of cutting tools, including compound impact drills. However, there is still a need to understand the interaction of cutting tools and rock formations. A better understanding of the process will allow for improved drillability and a higher rate of penetration.
In the present study, the effect of tool and rock drilling auger properties after grinding on the effectiveness of the pVARD tool was investigated. The results show that the application of natural rocks reduces the effective forces by more than 17%. This is due to the lower built-up edge. This makes it possible to increase the ROP with less energy. It also improves the ability of the pVARD tool to pre-fracture rock.
The laboratory PDC cutting tests were conducted on different rocks, such as silver quartzite, lamellar obsidian, and flint. The properties of each rock were analyzed to determine the optimum parameters for the novel tool.
Optimization of jet parameters and evaluation of rock-breaking effect
Increasing the speed and efficiency of a jet bit is a key technology for rock drilling. However, the measurement of rock mechanical properties in real time is extremely difficult. Particle jet impact drilling is a non-contact rock-breaking technique that has been studied for speed-increasing technology. This article summarizes key technologies of particle jet impact drilling and outlines the potential of this technology.
Particle jet impact drilling has been shown to improve drilling efficiency. Moreover, it can also reduce the cost of a drill job. In addition, it is an effective method to break rock.
The particle jet impact mechanism of rock drilling bucket breaking is based on a nonlinear response. The process is a combination of high-frequency impact of particles and high pressure and temperature. The result is an expansion of fractures and crushing of the rock. The resulting damage is accumulated, which causes the formation of a broken groove. The kinetic energy is transformed into heat energy, which is then transferred to the rock debris.
Application of particle jet impact drilling speed-increasing technology in the hard formation of deep and ultra-deep wells
Compared with other methods, particle jet impact drilling has been proven to be efficient and practical. It can enhance drilling efficiency, speed, and miniaturization. However, it also entails serious wear and tear.
Currently, research on rock-breaking technology of deep-well formation is still under urgent technical development in China. This method can improve the drilling efficiency and save drilling costs. It is important to develop mathematical models to evaluate the rock-breaking effect.
This method is applicable to strata with hardness up to 2000 MPa. High-velocity metal particles can produce large instantaneous impact stress. Combined with the hydraulic blow effect, the rock is broken. In the process of breaking, tensile stress and shear stress occur around the boundary of contact area. Using this method, the cutting speed of the bit teeth must be lower than the particle waterjet cutting speed.
This method is applied to deep and ultra-deep wells, which have complex drilling conditions such as high temperature, high pressure, high WOB, and high formation hardness. Therefore, it is difficult to achieve a constant-speed drilling process.