DRILLING TECHNOLOGY OF EXTENDED-REACH WELL WITH ULTRA-HIGH HORIZONTAL DISPLACEMENT TO VERTICAL DEPTH RATIO

After 8 years production period, Liuhua11-1 oil fields (the brief name Liuhua oil field) in the eastern region of South China Sea area, because total water-cut rises, the production decline quickly, and need adopt measures urgently to increase reserves and produces. Since 2001, we make use of sidetrack drilling at the well slot of original producing well successively, by extended-reach well with ultra-high horizontal displacement to vertical depth ratio and sidetrack drilling methods develop the reservoir of 3 wellblock which is apart from east limb of principal development area 4.5 km. Up to now, we have put into practice 4 sidetrack drilling extended-reach wells, 3 sidetrack drilling operation(according to the international standard, the 3 wells also belong to the extend-reach well), parts of 7 wells adopt rotary steerable drilling technique, and the drilling operation process is successfully. Among them the biggest horizontal displacement of B3ERW4 extend-reach well is 5634.07m, and the horizontal and vertical ratio attains 4.58, and is the biggest ratio in domestic, and lies at the 10th of the world. At the same time, these extend-reach wells with ultra-high horizontal displacement to vertical depth ratio continue to break and create many new records about ocean petroleum drilling and best score of business enterprise field. Practice demonstrate that the sidetrack drilling extend-reach well or sidetrack drilling method is a kind of valid and economic measure and way to simulation for Liuhua old oil-field in production tail. This kind of integrated development technique has great reference significance for the development of the shoal oil-field and satellite structure of the developed oil-field.