DRILLING TECHNOLOGY OF THE FIRST MEDIUM CURVATURE HORIZONTAL WELL DRILLED IN SANDSTONE RESERVOIR OF HUABEI OILFIELD

Huabei Oilfield are consisted of buried hill reservoirs of carbonate, and two horizontal wells as RH-1 and RH-2 were drilled in the carbonate reservoirs in 1990 and 1996. However, with years of development, fewer carbonate reservoirs are found while more sandstone reservoirs are discovered. To explore a new way for developing the reserves in the depleted oilfield, a horizontal well T4H1 is planed in the sandstone reservoir, which is the first medium curvature horizontal well in the sandstone reservoir in Huabei. The well was spuded on Feb. 25, 2004 and finished drilling on Mar. 12, 2004, with the max. hole inclination of 92.28°, max. building rate of 42(°)/100 m and min. radius of 136 m. The technology difficulties during drilling, solutions applied and successful experience were presented. The success of this well explored a new way of developing the depleted areas of Huabei Oilfield, and will expand the application of horizontal drilling technology in Huabei.