Gas Turbine Drilling Tool Geometry Research And Processing Realization

With the increasing difficulties in oil and gas exploration, and big price dropping of crude oil prices, the oil industry is confronting unprecedented challenges. To deal with complex technical problems and decrease cost of oil exploitation, technical promotion is the best solution to obtain economic benefits. For solving these problems, the underbalanced drilling technology is widely used in the actual project; on the other hand, the turbodrill is the branch of downhole drilling system, which is widely used in horizontal wells, especially used for deep well. The conventional turbodrill uses drilling fluid as its power source, which couldn't satisfy the requirement of underbalanced drilling. In order to solve the practical engineering issue, based on adequate literature research, this paper would carry on the research about optimizing the structure and design of traditional turbodrill, to satisfy the requirements of underbalanced drilling.Underbalanced drilling technology mainly uses gas currently. According to the characteristics of gas, this paper would firstly research the design methods and theories of traditional liquid turbodrill. Then conducts research on design theory of steam turbine and makes summary and conclusion. After the research of different turbine machinery, build the hypothesis of uneven output performance levels in different unit of turbodrill when it is used in the gas environment. In order to verify the correctness of the above assumptions, this paper chose WZ-115 type liquid turbodrill for the study. By using of CFX simulation system, this paper verified this type could satisfy the requirements of gas-using; and carried out the multi-simulation to simulate the working situation of 10 pair of stator and rotor blades. The result of multi-simulation data shows when WZ-115 turbodrill is used in gas environment, the fluid flow rate would arrive at the very large level, which resulted in the flow field dislocation and chaos.For solving above issues, this paper presents a variable geometry technology (VGT), and uses this technology to improve the overall efficiency of the gas turbodrill and decrease fluid flow rate by changing blade's geometry structure. Firstly, this paper uses CFX to simulate the single-stage stator and rotor blades with variable geometry, the simulation result shows that with the increasing of blade's setting angle, the output performance is obviously improved; Secondly puts modified setting angle blade on the last and last 3 stage of 10 pair of stator and rotor blades, after the simulation, the data shows the internal fluid flow field velocity decreased and the field dislocation and chaos were controlled by using variable geometry technology, and the overall efficiency of the gas turbodrill was improved.Through the studying of variable geometry technology, proved that this kind of technology would help improve turbodrill's overall performance when uses gaseous medium. To further verify the variable geometry turbine impeller is ready for actual processing, this paper based on UG software, carried out a new sort of processing technology by using three-dimensional modeling system.Through the studying of this paper, verifies the variable geometry technology (VGT) could effectively solve the problems and defects when traditional turbodrill is used in the gaseous medium. Through using this technology, the traditional turbodrill could satisfy the requirement of underbalanced drilling Technology without changing the blade profile, which saves time and costs of research and brings benefits for society.