关键词: 致密砾岩, 超长水平段, 轨迹控制, 油基钻井液, 韧性水泥, 安全下套管

Abstract: Drilling a horizontal well with ultra-long horizontal section in conglomerate reservoir of Mahu Oilfield in Xinjiang is faced with a series of potential problems，including large drilling torque，difficult-to-control well trajectory，low ROP，weak wellbore stability and difficulty in running in completion casing. Systematic drilling and completion technology for horizontal wells with ultra-long horizontal sections in conglomerate reservoir of Mahu oilfield has been developed by means of casing program optimization，trajectory design and control，selection of featured PDC bit，high-performance oil-based drilling fluid，R&D of toughness cement，and safe casing running technique. This technology was applied to the drilling operation of Well Mahu029_H in Mahu15 Well Block，and achieved successful drilling of a horizontal section as long as 3 038 m，smooth running of casing，and satisfactory cementing quality that meets the requirements of large SRV fracturing. A new record has been created for the longest horizontal section in Mahu Oilfield，which accumulated experience for future drilling operations of horizontal wells with ultra-long horizontal sections in Mahu Oilfield，and provided references for the same type of wells in other areas of China.

Key words: tight conglomerate reservoir, ultra-long horizontal section, trajectory control, oil-based drilling fluid, toughness cement;
safe casing running