Casing Hammers: Drilling with an Atlas Casing Driver.

Designed BY drillers FOR drillers !

Drilling With an Atlas Casing Driver

When marketing to those considering a casing driver for the first time we have found an underlying apprehension and doubt. Two months after the sale we find that the same driller is the best endorsement of our product.

The addition of a reliable and powerful casing driver opens up new geographical areas for a drilling company to operate. Discover what drilling companies in glaciated areas have known for decades--Drill and Drive!

Many drillers weld a “stop” to the top of their casing driver to keep the top head from hitting the top seal of the casing driver.		A “drill sub” made of the same diameter pipe as your drill steel is fabricated to a maximum length that will allow you to make up 20’ of drill steel below the casing driver. The “drill sub” should have a smooth outer surface and a leading bevel on the bottom to allow easy penetration of the casing driver’s top seal. Atlas top seals are a one piece “flexible cone” seal that is bolted into place, no need to adjust or tighten.
A standard 6” “suction hose” can be used as a discharge hose to direct cuttings away from the operator or helper. Altas Casing Drivers have a 6” male pipe thread on the discharge spout to make it easy to use a quick disconnect or barbed fitting.
		casing driver is normally at rest. Drilling can continue ahead of the drive shoe until the hole becomes unstable or the top head reaches the top of the casing driver (as shown). In certain formations drilling and driving at the same time is possible. When coming into contact with heaving sands and gravel, you are able to drive the casing ahead, maintaining control of the hole. Atlas hydraulic casing drivers can be used in these difficult situations without robbing the down-hole drilling air, providing safer and faster penetration rates.
Down hole hammers or roller bits can be used with a casing driver. Larger boulders can be drilled with an under reamer to allow passage of the casing.

When driving casing the bit is normally raised into the casing. This prevents the drill bit from being jammed or wedged into the formation by the drive shoe.
Some formations require aggressive driving, some a lighter “feel”. It is important to have a casing driver that provides positive driving control over a broad range of speeds. On occasion it may be necessary to “tap” the casing to determine its resistance. The Atlas casing driver has complete variable speed control. It is also able to produce a partial blow making it easy to “feel” your way along.

Driving casing when drilling in unconsolidated formations keeps the hole from caving while sealing the borehole from air loss. Up-hole velocities and cuttings removal are greatly increased. The casing also keeps the volume of cuttings lower.

Atlas hydraulic casing drivers allows you to keep all your air going down-hole while driving the casing. No need to rob air to run the casing driver. This provides better clearing of the cuttings when driving and helps keep the hole open in difficult formations.

Atlas manufactures a quality line of lifting accessories that enables you to efficiently and safely handle casing drivers on most top head air.

SWING JIB & HYDRAULIC LIFT CYLINDER
Both components have 8” steel sheaves with sealed bearings running 5/8” wire rope.

The rugged hydraulic lift cylinder features a 5” bore with 2” diameter rod. The rod end sheave block runs in a track to provide extra rigidity.

The swing jib has sealed bearings in the swing joint.

Control of the hydraulic lift cylinder is provided by a pressure relieved spool valve. The valve’s positions are: raise, lower, detented hang, and detented “float”. The valve’s pressure can be set to relieve if the rig’s top head hits the casing driver. This provides a safe lifting mechanism that is long lived and easy to operate.

Drilling and driving with a casing driver is commonly performed in areas where glacial till, overburden, unconsolidated formations or heaving sands are found. The addition of a casing driver to a top head air rotary rig will often greatly increase penetration rates and decrease startup time.

Although many users of casing drivers have developed their own methods the basic procedures are simple. A drive shoe is welded to the bottom of the first section of casing to be driven. The drill steel is “stabbed” into the casing then raised into the mast by a line equipped with a upper sling and a bottom hook. The bottom hook is designed to penetrate the hole in the pin end of the drill steel and allow the casing to rest on the shank. Once the casing is lifted in place the drill steel is made up, then the casing is welded.

The casing driver is then lowered onto the casing and allowed to “float” or follow the casing as it is driven down. A top seal and “wear ring” in the casing driver keep the cuttings from exiting the top, directing all the air and cutting through the discharge spout. A discharge hose can be attached to the discharge spout to direct the cuttings.