Wireline sidewall coring

In April 1989, Schlumberger Well Services, under contract to Fenix and Scisson of Nevada, Inc., ran a wireline sidewall coring machine in exploratory hole Ue4t at the Nevada Test Site for the Los Alamos National Laboratory. The sampling project goals were to recover material for geologic characterization and to determine the effectiveness of the tool for sampling various volcanic lithologies. If a wireline tool is found to be effective, fewer expensive continuously-cored holes will be needed. The Schlumberger Sidewall Coredriller has a maximum diameter of 5.25 inches and, with the gamma-ray unit included for stratigraphic correlation, is approximately 40 feet long. It weighs 850 pounds. All the downhole mechanical systems are hydraulic including the anchor shoe, the coring motor, the pressure on the bit and the core extraction system. Sonde functions are monitored and controlled at the surface. The tool is designed to run in fluid with the waterways in the diamond but creating circulation to keep the bit face clean. Up to 20 cores, measuring 0.91 inches in diameter by 2 inches long, can be recovered with each each. These cores are separated in the split-sleeve catcher tube by discs automatically inserted following each coring. 1 ref., 4 figs., 1 tab