For water well drilling rig,the general requirement: simple configuration,less energy consumption,easy operation,more moveable, Muti-functional, small size. In real application, the drilling rig selection has to be based on the stratum, hole diameter and hole depth as well as drilling method
- Machine price is the key factor for people to select suitable drilling rig, it is one time investment. The machine’s price increased along with increasing of hole diameter and depth.
- From Drilling method point of view, DTH drilling rig is more expensive than coring drilling rig and price of hydraulic drilling rig is higher than vertical shaft drilling rig, which is more mechanical drilling machine
- From mobility point of view, truck mounted drills cost more than crawler mounted drills.
2. Operational Cost
- Operational cost significantly affects the profit people can gain during drilling business. The net profit is the money driller get from well user from water well drilling minus operational cost.
- The operational cost contain people salary,cost of casing, mud and fuel as well as maintenance cost of drilling rig.
- From type of drilling machine point of view, Down The Hole(DTH) drilling rig has higher operational cost than rotary drilling rig working with mud pump. Because, the air compressor is needed for DTH drilling rig and its oil consumption is very much higher. The vertical drilling rig(mechanical driven) is more economic compared to hydraulic drilling machine.
3. Drilling efficiency
- Drilling efficiency depends on the stratum, skills/experience of operator, the type of drilling machine and drilling method.
- For rock condition,the most efficient way is to use down the hole drilling rig working together with air compressor.
- For soil, clay and sand condition, the best way is to use drilling rig with mud pump.
- For cobble stone, the reverse circulation system is most suitable drilling method. It just need to add a set of reverse circulation drilling tools to existing drilling machine.
- From working principle of drilling machine point of view,there are mainly 3 drilling method:
- Down The Hole drilling method which needs to work with air compressor. It is great method for rock condition.
- Rotary drilling with mud pump,it is more economical drilling way and fit very well for soil, sand and clay stratum, for rock its drilling speed will be lower compared to DTH drilling.
- Auger drilling, it do not need air compressor and mud pump during drilling. But it only can drill the soil, clay and sand.
- From drilling process point of view, we have 2 drilling method:
- Direct circulation drilling which the drilling fluid(air or mud) go through drill rod and take the cuttings via the space between outside of drill rod and wall of hole.
- Reverse circulation drilling, it needs dual wall drilling pipe. The drilling fluid go through the space between inner wall of outer tube and outer wall of inner tube. For cobble stone and sand, soil geological structure, it is most efficient drilling method.
5. Service after Market
- The service of after market is another key point for drilling rig selection. During the drilling operation, there will be issues happens on rig like components broken, mis-operation of rig. All this needs timely and professional guide from rig manufacturer. Otherwise it will affect rig user’s business
6. Availability of Spare Part
- People needs to consider the availability of spare parts when they buying drilling machine. It is part of operational cost. If the spare parts is not easy to get, it means you have to pay more to get it and cost longer time. All of this will definitely influence drilling business profit.
- The safety is first thing when selecting rig, including safety for operator, service people as well as people around the rig both during drilling and travelling.
- Therefore, the safety guard, emergency stop, dust collector is needed to protect people from death or injured.
8. Environmental Protection
- Nowadays, all countries take environmental protection to a higher level, so the engine emission level and noise level needs to be considered when selection rig.
- Buyer needs to refer to the country or area standard code where the rig will be used
Above is just some basic knowledge during drilling rig selection. It can be guide for business starter when they plan to buy rig.
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