中文摘要：

长水平段水平井能够增加钻遇油层的长度和数量,提高单井油气开采量,在薄油层开发、海油陆采方面具有明显的技术优势.但由于水平段过长,钻进过程中面临着严重的摩阻问题.以胜利油田某长水平段水平井为例,采用有限元方法,从井身剖面结构参数优化、钻井作业参数优选等方面,分析其对摩阻的影响规律及其内在影响机理.研究结果表明,案例井造斜段曲率半径对长水平段水平井摩阻影响较为明显,应综合考虑地层特点、造斜率控制难度以及后期送钻能力进行合理选取;起钻过快会导致钻柱与造斜段上井壁摩擦严重,下钻时应平衡下入效率、钻柱变形和摩阻的关系,防止遇阻;复合钻进时低速区的转盘转速不会引起摩阻的明显变化.

英文摘要：

The horizontal well with long horizontal section can increase the length and quantity of oil reservoir encountered and can raise the single well production of oil and gas, so that it enjoys obvious technical advantage in development of thin reservoir and the offshore and onshore development. However, owing to the long horizontal section, in the course of drilling operation, the serious friction resistance problem will be encountered. Taking a horizontal well with long horizontal section in Shengli Oilifeld as example, the ifnite element method is used to analyze its inlfuence law for and inherent inlfuence mechanism for friction resistance from the viewpoints of optimization of wellbore section structure parameter and selection of drilling operation parameters. The research results indicate that, the curvature radius of building-up section of such well has relatively obvious inlfuence on friction resistance of horizontal well with long horizontal section, so that it should be selected properly after considering the characteristics of formation, the dififculty in control of building-up rate and the drill-pipe delivery capacity in later phase, too quick raising of drill pipe will lead to serious friction between drill pipe and well wall on building-up section, and in the course of lowering of drill pipe, the relationship among lowering efifciency, deformation of drill pipe and friction resistance shall be properly balanced, so as to prevent the drill pipe from being jammed. In the course of combined drilling operation, the speed of rotary table in low-speed area will not cause obvious change in friction resistance.