WorldWide Drilling Resource

54 APRIL 2018 WorldWide Drilling Resource ® Environmental Monitoring by Thomas Kwader, Ph.D., P.G. Cores ~ Valuable Information for Understanding Subsurface Geology and Hydrogeology The two most common methods of drilling water wells are the cable tool and mud rotary methods. Both of these “destroy” the physical characteristics of the formations encountered. Unfortunately, the ge- ologic structure (bedding, porosity, etc.) is often crushed and appears as ground-up grains and mud. For- tunately, some worthwhile information relating to the water level and water-producing characteristics of the formations are revealed by changes in the drilling fluid levels while penetrating these formations. A formation that drinks water quickly will usually produce a lot of water if it is not a dry zone which is encountered. Other characteristics that are difficult to determine while drilling include the “connectivity between voids”, or the size of voids. Some formations can have 20%, 30%, or more porosity, but the permeability (ability of the well to produce water) depends on the connectivity, or flow, between the pores. Permeability is often influenced by the layering of clays between the water-bearing zones. Even thin horizontal clay layers will “prevent” the movement vertically to the zones contributing water to the well. If the borehole is composed of cemented sandstones, limestones, fractured shales, or dolomites, and will remain open, the drill crew may be able to insert a pump, and measure the water pumped over time to determine if the well will sustain a yield sufficient for the intended use. The drill operator can also obtain coring equipment for rotary rigs to recover rock and sediment cores. These cores, often in the two- to four-inch-diameter range, are very helpful in assessing the permeability of a formation. Core barrels can often yield cores of two- to ten-foot lengths, which can be preserved for future references or testing. Coring equipment and operation of this equipment is probably more trouble and expense than the average drilling con- tractor cares to undertake. Cores for your area may be available for viewing from your state government, or the U.S. Geological Survey. A call to view these cores may be well worthwhile. Tom Tom Kwader may be contacted via e-mail to michele@worldwidedrillingresource.com FRASTE Celebrates Success in Turkey! Adapted from a Press release by FRASTE S.p.A FRASTE S.p.A. is celebrating its recent success in Turkey. Over the past three years, 13 drilling rigs have been delivered to Turkish Ministries. One important contract between FRASTE and the Turkish Government Department for Electricity Production was for two rigs mounted on a 6x6 Iveco truck carrier, to be used for large-diameter reverse circulation drilling operations in open air coal strip mines. The second contract was signed at the end of the 2015, with the Turkish "General Directorate of State Hydraulic Works (DSI)", for 11 water well drilling rigs classified in two groups. The first group included ten FS 400 water well drilling rigs while the second group included a FS 500 water well rig. One of the most interesting innovations with these machines is their remote sur- veillance capability. This cutting-edge system is equipped with digital devices mounted on the drilling rigs. It sends real-time data to the Ministry Headquarter Department through a GPS system. This allows them to constantly check all drilling functions and monitor the geological conditions of the site. In addition to providing the 13 rigs, FRASTE provided on-site training for the local drilling team covering all technical, theoretical, operational, and practical aspects with knowledgeable and experienced tech- nicians and even supervised the start- ing operations on the jobsite. Turkish Dealer, Dizel Turbo Ltd., played an important role in this agreement between FRASTE and the Turkish Ministries and followed all the delivery, commissioning, and training stages. The company’s skilled staff also provided commercial and technical assis- tance to the customers. The outcome of the successful collaboration of FRASTE and Dizel Turbo led to DSI Turkish Ministry requesting two additional rigs later this year.