Investigation of the Key Technology for Large-Scale Directional Drilling Crossing for Oil and Gas Pipelines

Abstract

With the increasingly demand for oil and gas resource in China, the development of Chinese oil and gas pipelines is undergoing changes with each passing day. In recent years, a large number of world famous oil and gas pipelines have been built in China. These pipelines not only have the features of large diameter and long distance, but also pass through many regions with complex geological structure, and require high construction technologies, especially the construction difficulty of large-scale crossings is greater. At present, the common construction techniques used in oil and gas pipeline crossings include directional drilling, shield tunneling, pipe jacking and large excavation. With the characteristics of little environmental disturbance, low comprehensive cost, short construction period and high technological and economical feasibility, the technique of directional drilling crossing is preferred in the crossing of oil and gas pipelines. Thus, this paper focuses on the discussion of the key technologies for large-scale directional drilling crossings of oil and gas pipelines. Firstly, the components and construction process of large-scale directional drilling crossings are described. Then, the solutions to the key technological problems, such as drill path design, reaming process selection, mud formulation optimization, pull-back force estimation and drilling equipment allocation, etc., are investigated. Finally, a large-scale directional drilling crossing is illustrated to explain the concrete solutions corresponding to key technologies. The study results show that the reasonable technical support for direction, reaming, mud, equipment is the key to directional drilling crossings, which contributes to ensure the construction quality and progress of oil and gas pipelines.