RIASSUNTO
The use of the diamond drill as a means of securing information onstructural geology in connection with oil exploration was advocated for severalyears prior to actual field trial. As far as we know George E. Burton, a memberof the Institute, and at present geologist for the Humble Oil & RefiningCo., was the first one to recommend it in a published article. Early in 1917Mr. Burton, then assistant director of the Oklahoma Geological Survey, prepareda brief bulletin on this subject for the survey and it was issued as one of thesurvey publications in July, 1917. Data secured from diamond drill holes boredfor coal had been used in the study and investigation of possible oilstructures in the State of Illinois and among the earliest trials of diamonddrilling as a guide to oil exploration was certain work carried out under thedirection of the Illinois State Survey about 1920, F. W. DeWolfe then beingState geologist.
The Mid-Continent field soon recognized the value of this agency and inNovember, 1920, the first work of the kind in the Mid-Continent districts wasstarted in Kay County, Oklahoma. This form of investigation has become ofincreasing importance until now approximately 50 diamond drills are inoperation in various parts of North America working solely on the problem offurnishing structural data where surface exposures are absent or inconclusive.The greater part of these drills are at present in Northern Oklahoma andSouthern Kansas, although Texas and the Rocky Mountain region have seen a fairshare of diamond core drilling.
Drilling is usually carried out in a regular pattern, holes being located atevery section corner or every other section corner. Shorter intervals aresometimes necessary for close work. Frequently several drills will be placed onone block of leases in order to secure quickly the desired information.Drilling is carried to whatever depth is required to form a basis forreasonably accurate correlation. In most districts this means holes less than600 ft. deep.