Application of SDST in Guiding the String Design of Directional Crossing Reaming

With better economic and social benefits, the directional crossing technique has been widely applied in many Pipeline-Crossing areas such as wire cable, drain pipelines and oil-gas pipelines. However, there is serous problem in string designing especially when at reaming, for the drill tools failure easily leads to a terrible result of the Pipeline-Crossing project. And because the string is also the power transmitter and fluid exchange channel, it is important for the rational design of directional crossing string. This paper proposes an analytical method of the string used in directional crossing reaming based on the String-dynamics Simulation Techniques (SDST). In recent years, with the rapid development of SDST, it has been extensively used in oil-gas drilling and has become the gordian technique of directing and estimating the string structure and drilling parameters. Based on the Computer Aided Engineering (CAE), the Rotor Dynamics, the Geotechnics and the Engineering Fluid Mechanics, the SDST can rationally design the string structure and optimize the operating parameters that are fit for the predicted hole path and geologic conditions, make scientifical evaluation of mechanical parameters and the purpose of calculating its safety factor into reality. This is a pre-evaluated method of the design of directional crossing string and estimating the drill tools failures. The method had been verified through the project as the directional crossing Lan-Zheng-Chang refined oil pipeline, and the conclusion was in best agreement