ZJ40LDB is developed by SJ. It is innovative module type diesel and VFD combined driving drilling equipments with max lifting load of 505,800lbs (2250kN). The ZJ40LDB is a module-type drilling rig of improved design. The assembling of unique self-raising bootstrap mast and module type base is very simple as compared with the similar drilling rigs. Fewer trucks are required for its mobilization. The rig occupies small areaat site, and suits the operation in watery regions, swamps, hillocks, mountain regions and other regions with limited space.At the same time, the pump and rotary table are driven independently. This design the drilling rig is capable ofrealizing scientific drilling process of 3H (high displacement, high pump pressure, and high torque). Draw works and mud pump system driven by diesel engine. Rotary table driven by VFD motor. Low-position drawworks, hydraulic disk brake. Substructure height is 24.6ft(7.5m), clear height under rotary beam 20.7ft(6.3m). Integral drilling instrumentation and control system locatedin driller's house. Integral K mast. Main parameters of ZJ40/2250LDB are the following: Drilling depth(4-1/2"DP) ft(m): 13120(4000) Drilling depth(5"DP) ft(m): 10499(3200) Maximum hook load lb(kN) : 505800(2250) Drilling line diameter,in.(mm)/lines: φ1-1/4(φ32)/10 Maximum hook lifting speed ft/s(m/s): 0.75-4.92(0.23-1.5)(10 strands)