Testing the El Malpais auger bit

"Nobody can auger through consolidated formations." That's what Stewart Brothers Drilling was told, but we didn't let it stop us. At some locations, drilling methods are limited due to possible cross contamination in the soil. The hollow stem auger method is sometimes preferred because it does not introduce anything new into the boring, as is the case with drilling with mud or air. Stewart Brothers had already augered as deep as 340 feet on previous projects. But we had always encountered auger refusal once we reached hard basaltic formations. To deal with the unique challenges of augering in basalt, Stewart Brothers designed and tested a new hollow stem auger bit. Code named "El Malpais," this bit is capable of coring through some basaltic formations. The auger coring bit works in conjunction with standard 4 1/4" hollow stem augers. The core barrel can be run on rods or on a wireline. Initial tests were done at Stewart Brothers' facility in Milan, New Mexico, where basalt can be found a few feet below the surface. The bit successfully cored approximately six feet into the malpais formation. It did a good job of cutting the rock, but eventually got too hot, resulting in some bit wear. So some revisions were made after the initial test. The bit was officially tested in the field on March 27, 1996. Stewart Brothers used the bit to core 11 feet of basalt. To aid in the cooling of the bit, a small amount of water was poured down the inside of the augers during the coring process. When the bit was removed from the hole and inspected, it proved to hold up very well. There was some slight wear, but little damage was done to the cutters. Stewart Brothers sees tremendous potential for the "El Malpais" bit. The ability to get through hard formation stringers while augering will be very valuable to our clients. In the past, when these formations were encountered, the drilling was discontinued due to auger refusal. When your next project requires hollow stem auger drilling and the possibility of refusal exists, please contact us. We 'd like the opportunity to work with you and further develop this drilling technology.