Experts Discuss Future of the Turbodrill

Abstract

Turbodrill Components Appraised in Field Test Program by W.E. Bingman Turbodrill Operational Characteristics by J.A. Mitchell Why the French Turned to the Turbodrill by M.M. Brantly Featured at the first 1959 meeting of the Mid-Continent Section Study Group which recently met in Tulsa, Okla., were reports of turbodrill operational characteristics, an appraisal of turbine components by a coordinated field test program, a first-hand account of latest developments of the turbine by the French and a panel moderated question and answer session. The panel, moderated by Arthur A. Lubinski, Pan American Petroleum Corp., Tulsa, Okla., consisted of four authorities on turbodrilling. Panelists were Joseph A. Mitchell, manager, field and technical service department, Turbodrill Div., Dresser Industries, Inc., Dallas; W. E. Bingman, turbodrill project engineer for Shell Oil Co., Midland, Tex.; M. M. Brantly, president of Brantly Drilling Co., Inc., Midland; and Madden T. Works, manager of operations for Dresser's Turbodrill Div., Dallas. During the question and answer session inquiries from the floor regarding aspects of turbo drilling resulted in comments by the panel on fishing operations, costs of renting the turbo drill, excessive wear of thrust bearings due to abrasive fluids and many other topics of general industry interest in the turbine. Comparison of Fishing Operations In answer to a query to compare the rotary in the U. S. with the turbodrill in Europe regarding time spent on fishing operations, the consensus of the panel was that the percentage of time spent on fishing in this country is about the same in rotary drilling as with the turbine in France. Further discussion among the panelists indicated that in rotary drilling in France the percentage of time spent on fishing operations is several times greater than in the U. S. In other words, because of the difference in drill pipe quality, fishing considerations are important in drilling economics in the U. S. mainly for exceptional cases such as the drilling string being subjected to a high level of shock and vibration when drilling very large holes (15 in. or larger). In such cases turbodrilling with rock bits results in savings. Turbine Life Depends on Thrust Bearing The panel generally agreed that the life of a turbine is about 100 hours. The part which generally needs replacing at this time is the thrust bearing which wears out due to abrasive mud conditions. At this point the question was raised as to whether the use of extreme pressure lubricants would sufficiently prevent thrust bearing wear of rock bits by abrasive fluids in order that they might be economically used with the turbodrill. In answer, the panel jointly opined that these lubricants might somewhat improve rock bit performance, but limited field experience has not indicated sufficient improvement to make rock bit usage generally attractive in turbodrilling.