Selective Up-grading Provides Rigs for Deep Drilling

The drilling contractors of the Permian Basin have been hard-pressed to meet the demand for 20,000-ft drilling rigs since the discovery of the prolific gas reservoirs in the deep Delaware Basin. The demand came at a time when the contractors of the area had felt the economic squeeze to the point that they did not have the capital to purchase new rigs for this class of work. Now, three years later, it is obvious that the contractor has met this demand. By maximum utilization of his existing equipment, he has spent a minimum of money. This has required a careful analysis of each of the major rig components to determine what demands a 20,000-ft well will impose. New equipment has been purchased only as a last resort and most of the rigs in service today on these wells are the products of a process of selective up-grading of older rigs. By discussing each of these rig components, this paper will show what is required, when and where the horsepower is needed, and how and why the rigs that are working today have been assembled. The contractors have proven that these rigs are adequate and capable of successfully drilling deep wells. Introduction In Dec., 1965, there were 23 rigs in the Delaware Basin at work on wells scheduled to drill below 20,000 ft. An investigation of these 23 rigs surprisingly would show that just one of this number is a completely new rig. The remainder, although perhaps carrying a new company number, are the results of a process of selective up-grading of used equipment by the contractor.