海上高抗扭Ф127 mm柔性钻杆研制及应用

Development and Application of Offshore High Torsion Ф127mm Flexible Drill Pipe

为进一步实现海上油田深部低孔、低渗储层开发需求,提高单井产能,进行了海上作业高抗扭柔性钻杆的研究。通过模拟柔性钻杆内部球头连杆球面、异形密封圈球面及本体凹槽内表面相互作用关系,分析出柔性钻杆端面应力分布规律。研制的高强度柔性钻杆在乌石17-2区块Ax井的2个分支井进行了现场试验,试验结果表明:设计的单个Ф127 mm柔性钻杆通过API标准螺纹相连,采用纯机械造斜原理,能够实现16~20 (°)/m的高造斜率;配合斜向器回收技术,能够实现多个分支井同时量产,进一步增加单井泄油面积;钻杆采用铬钼钢材质,能够满足海上高摩阻、高转矩情况下的钻井技术要求,同时可适应高温高压地层钻井作业。高抗扭柔性钻杆的研制与应用为我国海上油气低成本高效开发提供技术支持。

In order to further realize the development needs of deep low-porosity and low-permeability reservoirs in offshore oilfields and increase the productivity of single wells, research on high-torsion flexible drill pipes for offshore operations were carried out. By simulating the interaction among the spherical surface of the ball-end connecting rod inside the flexible drill pipe, the spherical surface of the special-shaped sealing ring, the inner surface of the body groove, and the stress distribution law of the end face of the flexible drill pipe were analyzed. The field test was conducted in the S1 and S2 branch wells of Well Ax in the Wushi 17-2 block. The research shows that the designed Ф127 mm flexible drill pipe connected by API standard threaded connections can achieve a 16~20( °)/m high build rate. With whip-stock recovery technology, it can further increase the oil drainage area per well through multiple branch wells. The drill pipe was designed with Cr-Mo(chromium-molybdenum) steel material to satisfy high frictional resistance and high-torque drilling technology requirements. It adapts to HTHP(high-temperature and high-pressure)formation drilling. The development and application of high-torsion flexible drill pipes in offshore oilfields provide technical reference for the low-cost and high-efficiency development of offshore oil and gas in Chinese offshore oilfields.