Geophysical Log Sample Clauses

Geophysical Log. 1. When drilling has reached the prescribed final depth, the Contractor shall conduct a geophysical survey in the borehole. Acceptable service companies include Pacific Surveys, ▇▇▇▇▇▇▇ Well Logging, or equivalent as approved by the Engineer. The Borehole geophysical survey shall include spontaneous potential (SP), natural gamma, and multiple resistivity logs. 2. The spontaneous potential survey shall be plotted on a scale of one-inch equal to plus or minus 20 millivolts. The multiple resistivity survey shall consist of a point resistivity curve and multiple resistivity curves for 16-inch short normal and 64-inch long normal recordings on a one-inch equal to 20- or 40-ohm scale. All surveys shall be plotted on a depth scale of one-inch equal to 20 feet. 3. The Contractor is responsible for the integrity of the borehole to assure that the geophysical logging is successfully completed. The Contractor shall maintain circulation in the borehole with tools on the bottom of the hole until the logging equipment is on location and prepared to conduct the surveys. The logging service company shall have access to a ditch sample of the circulation fluid for calibration of the logs prior to ceasing circulation. When the logging service company is fully prepared, the Contractor shall pull drilling tools from the well and the logging services immediately commenced. If the logging tools fail to reach the desired depth, the Contractor, at Contractor’s expense, shall reinstall the drilling tools into the borehole, cleanout the borehole to the final drilled depth, and recondition the hole to allow for logging operations. 4. Upon completion of logging, the Contractor will deliver to the Engineer four (4) field prints and a digital file of the geophysical surveys, including the raw data (e.g., .las files). The Engineer shall approve the field copies of the surveys before the Contractor releases the logging service company form the site.