BH-VDT垂直钻井系统导向块结构优化设计及现场试验

Structure design optimization and field test on the guide block of BH-VDT vertical drilling system

我国多个油气田处于高陡构造、地层倾角较大地区,面临防斜打直和钻井提速的难题。渤海钻探自主研发的BHVDT5000垂直钻井系统在国内多个油气田进行了成功应用,但在个别井垂直钻井施工中发生导向块落井事故。通过导向块井下工作受力分析,认定事故发生的原因是单驼峰结构导致导向块接触井壁处于压缩状态时,弹簧销与导向块腰孔发生接触摩擦,从而磨损断裂。提出将导向块的单驼峰结构改为双驼峰结构的技术方案,同时在弹簧销内加入实体销和在导向块两侧设计挡板结构,防止复杂的工况把弹簧销带出。改进后的BH-VDT5000垂直钻井系统在塔里木油田山前克深1102井一开?558.8 mm和二开?431.8 mm井段进行了现场应用,取得了良好效果。

In China,a great number of oil and gas fields are located in high and steep structures and the areas with larger stratigraphic dip,so they are faced with the difficulties of inclination prevention and ROP improvement.The BH-VDT5000 vertical drilling system which is developed independently by CNPC Bohai Drilling Engineering Company Limited has already been applied in many domestic oil and gas fields successfully,but the dropping accident of guide block happens during the particular construction of vertical drilling.In this paper,the force applied on the guide block during the downhole operation was analyzed.It is confirmed that the reason for the dropping accident is that single-hump structure results in contact and friction between the spring pin and the waist hole of guide block when the guide block is in the state of compression while contacting the borehole wall,so that the guide block is worn and fractured.It was proposed to convert the single-hump structure of guide block into the double-hump structure while installing a solid pin in the spring pin and designing damper structures on both sides of the guide block to prevent the spring pin from being taken out in complex working conditions.The modified BH-VDT5000 vertical drilling system was applied practically in the first section(?558.8 mm)and the second section(?431.8 mm)of Well Keshen 1102 in the pediment structure of Tarim Oilfield,and its application effect is remarkable.