Drilling difficulties analysis for Donghe 1-H18C well

Donghe 1-H18C well is sidetracked directional well in Donghe 1 Block of Donghe Oilfield in Tarim Basin. The difficulties of drilling the well are that some layers with big difference of pressure gradient exist in the same borehole, causing the tendency of sticking; inclination angle is 57° and ? 127 mm liner is run in ?152.4 mm borehole, with small annular space, causing big risk in cementing. Because of the difficulties, drill pipe sticking and cementing pressure building accidents happen in drilling process. Through detailed analysis, the reason leading to the accidents was found and some essential treatment was taken to avoid them, which could play a directional role in field technical work.