The petroleum drilling rigs are classified into 5 grades by the nominal drilling rig range limit and the maximum hook load:
Model: ZJ30/1700, ZJ40/2250, ZJ50/3150, ZJ70/4500, ZJ90/5850

By the drive type: Electric Drive Drilling Rigs, Electromechanical Drilling Rigs, and Mechanical Drive Drilling Rigs

Model: ZJ30/1700J
ZJ40/2250DZ, ZJ40/2250DB, ZJ40/2250LDB, ZJ40/2250JDB, ZJ40/2250JD
ZJ50/3150DZ, ZJ50/3150DB, ZJ50/3150LDB, ZJ50/3150JDB, ZJ50/3150JD
ZJ70/4500DZ, ZJ70/4500DB, ZJ70/4500LDB
ZJ90/5850DZ, ZJ90/5850DB