DRILLING THE 8600m LARGE EXTENDED REACH WELL WITH STEERABLE ROTARY DRILLS IN THE SOUTH CHINA SEA

Well XJ24-3-A18 of South China Sea Oilfield is an extended reach well with a TD of 1800m, horizontal displacement of 7500m, and a VD of 2740m. When a well is drilled to 7000m, hole deviation becomes very difficult to control under rotary drilling, and drifting will occur at the same time. As for slide drilling, it produces high friction, and drilling is difficult and low ROP is achieved. A steerable rotary drilling tool called power drive is run into the well in 6871m, and it achieved good results without changing the drilling parameters too much. Static inclination and azimuth changed evenly, no drifting was found and no severe dog legs were made. ROP was almost improved 10 times, and the total costs were reduced therefore.