Study on Waidiao-Cezi Island Pipeline Crossing Parameters and Schemes Optimization

摘要

The mechanical parameters in construction of Waidiao-Cezi island pipeline crossing by Horizontal Directional Drilling (HDD), including bending radius of pilot holes and pullback load, are studied theoretically. The deficiency of empirical formula is pointed out, the basic factors which influence the HDD project are discussed, and the theoretical formulas are presented. In the meantime, the new concepts of the required minimum and allowed maximum mud pressure are given and the formulas considering the fundamental role of mud in the process of drilling are obtained. As an example, the Waidiao-Cezi island pipeline project crossing by horizontal drilling is analyzed and the theoretical quantitative values of crucial crossing indexes are obtained. According to the analysis and comparison of crucial mechanical parameters, the scheme for the Waidiao-Cezi island pipeline is optimized. The best scheme is confirmed from the three schemes, which is proved to be a success.