1. Over the drilling crew is the tool pusher. He has charge of one or two or three or four wells, and sees that they have supplies and equipment and and keeps going diligently. The statement "Harry Gray is pushing Prairie tools in Ada" does not depict Harry at the handles of a plow; it means that Harry is overseeing the drilling of Prairie Drilling Company's wells in the Ada district of Oklahoma.


2. At last comes the fateful day when the well reaches the sand in which oil is expected. Everyone holds his SPECIALISTS IN COMPLETION, LOGGING AND TESTING breath while the drilling crew "drills-in" the well and specialists "core", "log" or "drillstem test" it. The well may be dry - at least four out of five wildcat wells are dry. It may be an oil well or gas well, to everyone's joy. Or it may be a teaser, with a show of oil but not enough to be of commercial value.

3. In recent years science and the oil industry have developed more and more special techniques and tools for measuring the characteristics of a sand and its contained fluids. Contractors (called service companies) now will, upon the SPECIALISTS IN COMPLETION, LOGGING AND TESTING tool pusher's call, drillstem test his well, or log It by one or more of several methods. The service company men arrive at the well as fast as their cars and trucks can get there, and within minutes the drillstem test engineer may be supervising the drilling crew in lowering several thousand dollars' worth of his company's special pressure gauges and packers into the hole at the bottom of the drill pipe to sample the well's fluids and pressure.! The loggers will lower their electrodes and sounds into the well on a cable, and deliver a record SPECIALISTS IN COMPLETION, LOGGING AND TESTING of the well's electrical and radioactive characteristics, temperature, and diameter. Other common logs are records of sound-wave velocities and "dips" or "tilts" of the rock the well penetrates.

4. The logs and tip drillstem test may show that the sand is "tight", which means lacking in porosity. If so, a wellshooter may arrive. He makes his living by exploding nitroglycerine in wells to shatter the producing sands and improve the productivity. Well-shooting was formerly one of the most dangerous occupations. A hard bump in the road or a slip at the well head, and the well-shooter SPECIALISTS IN COMPLETION, LOGGING AND TESTING could not be found or assembled for burial. Improved technique and materials have lessened the hazards, and shooters now can give thought to such things as arteriosclerosis and old-age pensions.

5. Many tight formations can be made to yield their oil or gas by tracing (it rhymes with cracking), in which case the tracer creates cracks in the oil- bearing formations with a particular mixture of sand and oil or other ingredients injected at high pressure into the well, thus providing an access to the well through the formation.

6. Where nature has cemented the oil-bearing zones with SPECIALISTS IN COMPLETION, LOGGING AND TESTING limestone, the acidizer may be called on. He comes with truckfuls of tubing, carboys, and pumps and dissolves the lime out of the sand with hydrochloric acid. Fracing and acidizing require skill and training, and the fracer and acidizer are usually chemists or engineers or both.