Tophole Rigs, Shallow Oil & Gas Drilling
DER has been very active lately in the tophole drilling and shallow rig markets. The activity indicates that although the “big rig” market is not by any means tight, the efficiency and lower cost of operations for “super singles” is becoming more popular.
Packages including Schramm Telemast 200XD units, GEFCO SS200 units and Atlas Copco RD20 drilling rigs are being utilized to drill and set surface casing strings. Currently in the Permian Basin, these rig packages are drilling 17-1/2″ diameter hole and setting 13-3/8″ casing to around 2,100 ft.
The flexibility of drilling methods make these tophole rigs and rig packages so popular.
Many drilling contractors are outfitted with both air compressors and mud pumps and able to drill either with air or fluid depending on their formations.
In the case of air drilling, the cost per drilled foot can be a savings to the DC of 4-6 times compared with mud drilling costs.
A typical air drilling package will include multiple Ingersoll-Rand or Sullair Air Compressors, 1170 cfm @ 350 psi, and Joy WB12 Booster compressors.
Stand alone mist pump packages including a Kerr or Gardner Denver plunger pumps offer high pressure foam and polymer injection to the air stream incase booster compression is required by the formation to lift the drill cuttings to the surface of he borehole.
In areas where traditional mud drilling is required, a popular choice for DCs are 12″ to 14″ stroke duplex mud pumps.
I have seen many EMSCO D375 packages out there recently. These skid mounted or trailer mounted mud pumps will provide from 300 – 700 gallons per minute and commonly utilize refurbished CAT or Detroit Engines.
We highly recommend a mud cleaning system including a good shale shaker and some desanding & desilting cones. Custom pit systems are required for these type of drilling rigs due to the height of the rig floor and flow line coming out of the diverter.