鲁迈拉S 型定向井降摩减扭技术

Friction reduction and torque minimization techniques for directional wells in S-shape in Rumaila

陈绍云

CHEN Shaoyun

大庆钻探工程公司钻井工程技术研究院

Drilling Engineering Technology Research Institute of CNPC Daqing Drilling &

为降低鲁迈拉S 型定向井摩阻扭矩，针对鲁迈拉地质特点和钻井难点，建立了井眼轨道曲线计算模型，并开展了三项提速技术试验。从而确定了轨道剖面为五段制，最优井眼曲率为2.85~3（°）/30 m、最大井斜角为30°。对于水平位移大于500 m 或Mishrif 层定向钻进的S 型定向井采用旋转导向系统钻进可缩短钻井周期3 d 以上，而其余的井则推荐采用常规定向+ 水力震荡器组合方式，可提高机械钻速35% 以上，缩短钻井周期1 d 以上。通过3 种液体润滑剂和超细石墨固体润滑剂的优选复配与应用，裸眼内摩阻因数由0.52 降至0.35，套管内摩阻因数由0.35 降至0.28。通过上述技术的综合研究与应用，鲁迈拉S 型定向井实际顶驱扭矩降低30% 以上，尤其是随着井深和水平位移的不断增加，部分井扭矩降低近150%，机械钻速提高37.73%。

To reduce frictional torque in S-shape directional wells in Rumaila, according to geologic conditions and difficulties in drilling operations in Rumaila, a model for calculating borehole trajectory has been built, and three speed-enhancing techniques have been tested, which shows the trajectory profile should have five segments, with the optimal borehole curvature of 2.85-3(°)/30 m and maximum deviation angle of 30°. For wells with horizontal displacement of over 500 m or directional wells in S-shape drilled in the Mishrif Formation, using rotary steering system can shorten the drilling cycle by over 3 d. As for other wells, combination of conventional directional + hydraulic oscillator is recommended, which can enhance ROP for over 35%, and shorten drilling cycle by over 1d. Three liquid lubricants and solid lubricant made of ultra-fine graphic were used in different combinations to reduce internal friction factor in open-hole from 0.52 to 0.35, whereas the friction factor in casing reduced from 0.35 to 0.28. Through comprehensive development and application of above techniques, actual torque in top drive for drilling of directional well in S-shape in Rumaila can be reduced for over 30%. With the increase of well depth and horizontal well displacement, some wells reduced by up to 150% in torques, and enhanced by 37.73% in ROP.

10.13639/j.odpt.2016.04.008