Foreword

Standards exist to facilitate communication and improve the efficiency of transactions between manufacturers, vendors and users. Manufacturing drilling specialty tools for sale, and carrying them for rental are capitalintensive enterprises. Changing standards increase risks for obsolescence of plant and inventory. Nonuniform market perceptions of what constitutes minimum acceptable properties elevate these risks. Manufacturers and vendors can serve the operator community better if they can avoid uncertainty about, and unreasonable variety in the requirements of the products they must make and hold. On the other side of the equation, operators, who most often use these products on a rental basis, and who rarely have major investment in plant and inventory for drilling tubular production, face significant economic risk in the event of failure. In renting drilling specialty tools, operators need flexibility and good product properties to safely handle a wide variety of downhole conditions and loads.

This Volume 4 of Fourth Edition is the first time the DS-1^® sponsor group has elected to address load rating, inspection, assembly, testing and use of drilling specialty tools under the DS-1 forum. Standard STC-1™ covers qualification requirements for specialty tools. Also, Standard DS-1 Third Edition, Volume 3 included limited requirements for inspection, assembly and function testing of certain specialty tools. However, the requirements specified in these two standards were not completely aligned. Differences in coverage and requirements in Standard STC-1 and Standard DS-1 Third Edition, Volume 3 creates market confusion and places burden on the manufactures and vendors as they try to standardize and streamline their tool inventory. It also diminishes the market consistency that operators need to be able to standardize the drilling specialty tools they want to use for various service conditions and applications. As the DS-1 sponsor group examined these points, it became apparent that a single specification that covers qualification requirements of drilling specialty tools was needed.

To consolidate the requirements on drilling specialty tools into a single specification, the applicable requirements from Standard STC-1 and Third Edition of Standard DS-1 Volume 3 were merged to create a single standard; Standard DS-1^® Volume 4.