STATISTICAL ANALYSIS OF DRILL PIPE FAILURES OF STRENGTH GROUPS G-105

Characteristic types of operational defects which formed on the inner or outer surface drill pipes strength group G-105 are described. The results technical diagnostics were used when drilling wells in territory Dnipro-Donetsk gas-oil-bearing region. In 2018-2019, Ukrburgaz Drilling Department rejected 89 at a depth 4,000 to 6,000 meters. 
 A statistical evaluation discovered during deep (4-6 km) was carried out. Potentially dangerous areas pipe upset zone, length string, and duration operations determined. It is recommended that, performing defectoscopy string pipes, increased attention should be paid section from coupling face nipple, range 0.55 0.63 m. addition, taking into account drilling, diagnosis their placement, since interval 0.43 0.52 along relative () there greatest probability an defect. also necessary pay operations, particular, two stages distinguished: Stage I – stable operation (up 6 thousand hours); II stage - accelerated destruction (from hours more), it established that defect inspection pipe, special 2692 3736 hours, 8744 10983 these periods unacceptable