Innovative Metal Seal Roller Cone Bit Cuts Drilling Costs in Abu Dhabi Onshore Fields by 42%

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe positive economic impact of a metal bearing seal on roller cone bits used in conjunction with downhole motors and steerable systems in a Abu Dhabi Onshore fields has been dramatic. The metal seal has proven its ability to extend seal/bearing life of roller cone bits significantly (one million bit revolutions or 1000 krevs without seal failure are common) relative to elastomer sealed bits. This bearing, along with an improved cutting structure, has resulted in more on bottom drilling time.The metal seal technology is especially useful when used on steerable motor assemblies. The bits have been successfully applied to kick-off from vertical and generally drill the 8-1/2" build section between 8°-14°/100 ft to the landing point at 90°, through interbedded formations ranging from soft shales to medium-hard limestones. Unconfined Compressive Strength varies from 5,000 psi to 15,000 psi. As the bits were applied throughout the region, the manufacturer used step changes to improve the cutting structure and hydraulics to further enhance bit performance and durability.The authors will document significant cost reduction through improved bit performance in high-speed directional applications for the new metal bearing seal design compared to the best performing elastomer sealed bits. The study will include data from 386 bit runs totaling over 232,734 feet and 15,821 drilling hours documenting a decrease of 42% in cost per foot or a saving of US$3,836,400 over a three year period between

Innovative Bearing and Seal Package Improves Rollercone Bit Performance and Reliability

“…1 The dual dynamic seal technology compares favorably to metal seal bearing rollercone products. [2][3][4][5][6][7] Additionally, the leg journal and cone bore are re-designed with a tighter and more tortuous space to reduce the amount of hard, abrasive formation and solid particles in the drilling fluid from entering the seal gland. This provides a cleaner sealing environment and prolongs the seal life further.…”

New PDC Design Process Solves Challenging Directional Application in Abu Dhabi Onshore Fields

“…1 From the start it was apparent that the PDC design application team would need to look for fit-for-purpose bit/motor combinations to get the best performance consistently. Since the directional requirements of the BHA were unchanged, the team decided to stay with the same BHA geometry.…”

“…1 Despite advances in directional drilling technology and more powerful positive displacement motors (PDM), even as recently as late 2001, IADC code 517 roller cone bits were the only technology that could provide both tool-face control and build up rates required for the well plans. 1 Despite advances in directional drilling technology and more powerful positive displacement motors (PDM), even as recently as late 2001, IADC code 517 roller cone bits were the only technology that could provide both tool-face control and build up rates required for the well plans.…”

Optimization of cone bit bearing seal based on failure analysis

“…5 After that, many investigations and applications showed the superiority of the bimetal seal, which brought significant economic benefits to the drilling industry. [6][7][8] Chen analyzed the force and working environment of the cone bit, considered that the early failure of the rubber seal was severe, and proposed to use polytetrafluoroethylene as the sealing material. 9 Luo et al 10 conducted an experimental study of the metal seal and pointed out that the seals effectively adapted to the vibration conditions and had the advantages of low leakage and long service life under high speed conditions.…”