Safety is goal for Atlas Copco’s Automatic Pipe LoaderApril 13th, 2012 | Posted by in RD20
Drilling companies expect safer drilling features from equipment innovations that reduce the chances of crews putting themselves in harm’s way.
The new automatic pipe loading and handling system on the Atlas Copco RD20 exceeds expectations of safety while making drilling operations faster.
One drilling company in the Surat Basin, Australia, is relying on the safety and reliability of the RD20. Safety is a top priority for both the drilling and energy companies and is a driving force for implementation of new processes and tooling. The challenge is to reduce situations that compromise safety. Atlas Copco has designed an automatic pipe loading system (APL) for the RD20 for that purpose.
This new APL does not require any hands to touch the pipe from the time it arrives at the site and is loaded onto a rack system to the point it’s added or removed from the drill string. The APL is operated by the assistant driller standing off to the side of the platform, just over the driller’s shoulder. He controls the functions with a wireless remote control unit that can rest on a stand or be carried with a shoulder harness.
The APL handles drill pipe, collars, and Range 3 casing of varying sizes up to 13 3/8 inches. Hydraulic slips allow pipes to fall, one at a time, into the cradle of the pipe-loading arm. Clamps are engaged and the loading arm is raised into position under the rotary head. Additional safety is built into the clamping system, which cannot disengage if the pipe is raised above 15 degrees. The operator and pipe handler must be in communication, as the pipe can only be released when the driller releases it.
This company has installed a camera system at the top of the tower so the driller can see when the pipe is properly threaded into the top drive. This saves the driller’s neck from straining to see the operation from the working floor. The camera also ensures proper connectivity before he releases the clamps from the loading arm.
During the process, driller and assistant driller stand about 6 feet (2 meters) apart, allowing them to communicate every step of the way to ensure a proper connection is made. The floorman also has visual and verbal communication with the others so he knows when to pull the slips holding the oilfield-style pipe.
The men are a coordinated team moving quickly. The aid of automation is a big safety factor as it reduces excess fatigue when changing pipe or adding casing.
Including connections, the crew averages a rate of 121 feet (37 meters) an hour when advancing the drill string. The drill crew was averaging 262 to 328 feet (80 to 100 meters) an hour instantaneously drilling and 114 to 147 feet (35 to 45 meters) an hour including connections. As a specific example, they had just finished a well in one full shift and an hour into the next shift. That was 2,130 feet (650 meters).
They also use the Pason data system, which can be viewed at the driller’s station, inside the company trailers and from any office around the world.
Finding the seams
The formation in this region of Australia consists of Springbok Sandstone just below the overburden, Upper and Lower Juanah down to 525 feet (160 meters), and then Tangalooma Sandstone to about 850 feet (260 meters). The coal lies below these strata in the Taroom and Durabille coal seams. In the area photographed, the hole reached total vertical depth at 1,568 feet (478 meters). The deepest they will run in the area is around the 2,295 foot (700 meter) range.
The coal is found in multiple seams 1 ½ to 6 ½ feet (½ meter to 2 meters) thick with sandstone between. Once they drill to total depth they open each seam with a 16- inch reamer. The reamer collapses as it moves down, with teeth that can expand when they reach the seam.
The hole is drilled with an 8 ½-inch PDC bit. They use 4-inch drill pipe and 5 ½-inch collars. They will use two stabilizers 50 feet (15 meters) back from the bit and 10 collars at the bottom of the drill string.
Specifications require the drilling company to use three sizes of casing with the APL including the 14-inch conductor casing, 12 ¼-inch surface casing and 7-inch production casing—each cemented in place after being set.
When complete, the lower half of the production casing will be perforated pipe. A packer is cemented to seal off the surface aquifers from the production zones.
To drill the hole they will use 450 gpm of fluid mud, which keeps it clean and stable. The gas isn’t under pressure and water must be removed to get the gas flowing, so they are not using heavy mud while drilling.
Can they keep up?
The enhanced safety in the RD20 has not come with a trade-off in the rig’s productivity. In this case it has taken just eight to 10 hours to move the entire set-up three miles (five kilometers). They were able to finish one well to spud in the next in less than 24 hours. That includes everything. They are definitely still keeping up.