川东高陡构造上部大倾角地层钻井防斜技术研究

RESEARCH ON DRILLING INCLINING PREVENTION TECHNIQUE FOR THE UPPER FORMA TION WITH BIG DIP OF THE HIGH AND STEEP STRUCTURE IN EAST SICHUAN

川东高陡构造上部地层倾角较大 (最高达 85°) ,其大倾角地层铅垂厚度一般在 15 0 0～ 2 5 0 0m ,岩性以泥页岩为主 ,该段钻井井斜控制难度大、钻井速度低。针对这一钻井难点 ,开展了钟摆钻具、偏轴接头、钟摆钻具带偏轴接头等防斜钻具结构的研究试验和对比 ,钟摆钻具带偏轴接头钻具结构在井斜控制相当的条件下钻压较其它防斜钻具结构有较大提高。通过在天东 85等井试验钟摆钻具带偏轴接头钻具结构取得了显著的经济技术效益。

The stratigraphic dip in the upper formation of the high and steep structure in East Sichuan is very big (the biggest one comes up to 85°). The plummet thickness of the formation, mainly with mud shale lithology.is generally 1 500∼ 2 500 m. There is a lot of difficulties in deviation control during dilling in the formation and the drilling speed is alow. Aimed at the problems, the textures of the inclining prevention drilling tools, such as pendulum drilling tool, eccentric shaft joint and the pendulum drilling tool with eccentric shaft joint etc. , are researched and contrasted by experiments, the big weight of the pendulum drilling tool with eccentrict shaft joint is increased considerably as sompared with the others in the same conditions. Through the experiments of well Tiandong- 85 and other wells, remarkable economic benefits are obtained by using the pendulum drilling tool with eccentric shaft joint.