Drilling equipment organized around depth, load and deployment.

Operating requirement

Match the rig configuration to the field plan.

A drilling equipment scope needs more than a horsepower number. Depth, drill pipe size, hook load, mud circulation, mast dimensions, foundation conditions and well-site movement all affect the final configuration.

Step 1: Sort the rig classes by drilling depth.

The published nominal drilling depth is the first sorting criterion, because it already bundles the mast, the hook load and the circulating system into a coherent class. The skid-mounted drilling rig range in the ZYT line steps up from a 1000HP class to a 2500HP class, and the two depth columns (114mm and 127mm drill pipe) show how the same rig is re-rated when the drill string gets heavier:

Skid-mounted drilling rig range (published figures)

Parameter	ZJ40D (1000HP)	ZJ50D (1500HP)	ZJ70DB (2000HP)	ZJ80 (2500HP)
Nominal drilling depth (114mm DP)	2500-4000 m	3500-5000 m	4500-7000 m	6000-9000 m
Nominal drilling depth (127mm DP)	2000-3200 m	2800-4500 m	4000-6000 m	5000-8000 m
Max. hook load	2250 kN	3150 kN	4500 kN	6750 kN
Traveling system	5×6	6×7	6×7	7×8
Mast (type / height)	K type / 43 m	K type / 45 m	K type / 45.5 m	K type / 48 m
Rotary table opening	φ700 mm (27.5")	φ952.5 mm (37.5")	φ952.5 mm (37.5")	Φ1257.3 mm (49.5")
Substructure height	7.5 m	9 m	10.5 m	10.5-12 m
Drawworks power	735 kW (1000HP)	1100 kW (1500HP)	1470 kW (2000HP)	2210 kW (3000HP)
Mud pump (qty × power)	2 × 1300HP	2 × 1300HP	2 × 1600HP	3 × 1600HP
Diesel generation (qty × power)	3 × 1000 kW	3 × 1080 kW	3 × 1200 kW	5 × 1200 kW
Solid-control mud tank capacity	≥180 m³	≥320 m³	≥360 m³	≥600 m³
Drive type	AC-VFD-AC, stepless speed regulation

For a project rated around 4000 m with 114mm pipe, a 1000HP class rig already covers the depth, but the decision between 1000HP and 1500HP is usually made on hook load reserve, casing size and the mud tank volume needed for the drilling fluid programme, not on the depth column alone.

Step 2: Read hook load and the traveling system together.

Hook load determines what the mast and the traveling system can lift, and the two numbers must be read as one set. In the skid range the traveling system grows from 5×6 on the 1000HP rig to 7×8 on the 2500HP rig while the hook load rises from 2250 kN to 6750 kN. When a tender specifies a maximum casing string or a landing load, compare it against the rated hook load and ask the supplier to confirm the static load capacity of the mast, which is published separately from the traveling rating.

Step 3: Match the power, mud and control package to the circulating plan.

All four skid classes use AC-VFD-AC transmission with stepless speed regulation, which gives the driller precise torque control on the drawworks and the rotary table instead of mechanical gear steps. The practical difference between the classes shows in the support system: mud pump capacity rises from 2×1300HP to 3×1600HP, and the solid-control mud tank grows from about 180 m³ to 600 m³. For deep wells with high circulating volume, confirm the mud tank capacity and the high-pressure manifold rating together with the pump package, because they limit the circulating rate as much as the pumps do.

Step 4: Choose the mobile class when the rig must move between pads.

When the programme moves the rig between pads or leases, the truck-mounted mobile rigs cover the 3000-4000 m band with their own transport built in. The two published models differ mainly in power and mast height:

Mobile drilling rig comparison (published figures)

Parameter	3000m Mobile Rig	4000m Mobile Rig
Drilling depth (4½" DP)	3000 m	4000 m
Max. load	1800 kN	2250 kN
Max. fast rope pull	280 kN	280 kN
Rope dia / effective qty	Φ32 (1¼") / 10	Φ32 (1¼") / 10
Max. hoisting speed	1.4 m/s	1.4 m/s
Travelling system	5×6	5×6
Engine	CAT C15 / 540 bhp × 2	CAT C18 / 630 bhp × 2
Transmission	Allison M5620AR × 2	Allison M6620AR × 2
Mast clear height	38 m	39 m / 38 m

The 4000m model keeps the same rope and traveling layout but steps the engine and the mast up, which is what carries the extra 450 kN of rated load. Confirm the moving dimensions and the axle configuration against the roads on the route before committing the model to a lease.

Step 5: Moving a fixed rig between sites with a rig moving system.

For skid rigs and heavy truck-mounted rigs that must relocate, ZYT supplies a land rig moving system rather than leaving the move to crane and trailer work. The integrated system is rated for 300-480 t of total rig weight with a moving capacity of 400-540 t, a ground clearance of about 600 mm and a road speed of up to 8 km/h, designed for road widths around 12 m and an ambient range of -17 to +55 °C. Mast moving equipment and substructure moving equipment are offered separately, so the scope can be limited to the parts of the rig that actually travel.

What to confirm before the model is final.

Send the target depth, the drill pipe size, the expected casing programme, the mud circulating rate, the site foundation or relocation requirement and the transport constraints. The supplier then matches the rig class, the power and mud package and the moving scope to the project, and confirms the documentation and commissioning support in the quotation. This sequence keeps the technical review on published parameters instead of on the horsepower number alone.

Check the mast, the substructure and the rotary table against the well-control plan.

The drilling envelope is not complete without the mast, the substructure and the rotary table, because they set what can pass through the wellhead and how the BOP stack is handled. In the skid range the rotary table opening grows from φ700 mm (27.5") on the 1000HP rig to Φ1257.3 mm (49.5") on the 2500HP rig, which tracks the surface casing sizes the class is expected to run. The substructure height steps from 7.5 m to 10.5-12 m, and this dimension decides the clearance for the BOP stack, the wellhead equipment and the rig floor operations at the well. For the mobile rigs the mast clear height of 38 m (3000m model) or 39 m/38 m (4000m model) fixes the stand length the rig can handle. When the tender names a casing programme and a BOP requirement, compare them against the rotary opening, the substructure height and the mast clearance before the rig class is fixed, and confirm the high-pressure manifold rating together with the mud pump package so the circulating and well-control sides of the package stay consistent.

Solid-control and mud tank sizing complete the circulating review.

The circulating system is sized by the mud tank capacity and the solid-control scope, which grow with the rig class: the published effective capacity runs from at least 180 m³ on the 1000HP rig to at least 600 m³ on the 2500HP rig. For a deep well with high circulating volume, the tank capacity, the mud pump package and the high-pressure manifold rating must be reviewed as one system, because a small tank or a low manifold rating will cap the circulating rate no matter how much pump power is installed. Include the mud programme and the expected circulating rate in the inquiry so the supplier can confirm the tank and manifold scope rather than quoting the rig package alone.