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Hydraulic Fracturing Techbook 2018

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EPmag.com | August 2018 | 43 Hart Energy IndustryVoice ® allows marketers to reach our audiences by enabling them to create and place relevant content in our media channels – in print, online, via social media and at live events. Each IndustryVoice ® piece is produced by the marketing sponsor and any opinions expressed by IndustryVoice ® contributors are their own. For questions about IndustryVoice ® programs, email IndustryVoice@hartenergy.com. Frac fluid ends are still considered expendable – albeit the most costly expendables on a frac spread. When a fluid end must be swung from the pump for repair or maintenance, it is easy to lose track of pumping time to-date on a unit, then "best guess" hours when it returns to service. Maintaining frac pumps is challenging; keeping accurate service records adds to the challenge. The number of high-pressure hours a fluid end can withstand is highly debated. A fluid end may fail in two hours if a packing-bore greaser malfunctions. A fluid end may last 200 pumping hours and experi- ence a valve seat-deck washout. Or it may accumulate 2,000+ pumping hours before it is decommissioned and retired to the boneyard. Its ultimate failure mode is determined by random operating conditions and thoroughness of routine maintenance. Five fluid-end failure modes were identified in a 2016 Upstream Pumping article "The Five Failures of Fluid Ends." Kerr Pumps addressed these fail- ure modes with its Super Stainless™ metallurgy, design-specific intersecting bore geometries, and patented Super Seal™ technology in the packing, suction and discharge seal bores. With longer oper- ating life, two more failure modes occur at a growing rate: Thread cracking/face peeling at the suction retaining nut, and opposing stress-cracking at the connecting flange. Kerr Pumps responded to the 6th and 7th fail- ure modes with the January 2018 rollout of its pat- ent-pending Frac 1 CONNECT™ fluid end. The F1C™ incorporates a bolt-on cover cap to disperse cyclic stress (more than 287,000 pounds) on suction caps across eight, gall-free studs and nuts. Additionally, Kerr Pumps engineers began seeing minute flexing cycles at the connecting flange in FEA simulations. This led to a two-piece flangeless design that attaches a highly rigid CONNECT™ plate to the power-end's stay rods. With a Frac One™ fluid end attached to a CONNECT™ plate, flexing movement was reduced by 420% –likely contributing to longer packing and stay-rod life observed in field trials. Reliability is Like Buying Uptime Fracs are more efficient when pumps have less down time –longer operating life at lower total cost. Two widely accepted Key Performance Indicators (KPIs) for frac equipment are: n Total Cost of Ownership (TCO) – accumulated costs over equipment's operating life n Non-Productive Time (NPT) – time on site when planned work cannot be performed Frac fluid-end TCO can be significantly higher when full operating life is shortened by premature failure. Total costs accumulate rapidly when routine maintenance occurs at compressed intervals. Argu- ably the most menacing demon on frac jobs is NPT – missing schedules when a pump is offline. Like any corporate asset, it is not Returning On the Investment (ROI) when it is not generating profitable revenue. To improve these time-related KPIs, it pays to find ways to extend these reliability measures: n MTBM – Mean Time Between Maintenance n MTBF – Mean Time Before Failure Make no mistake: High-pressure fracturing today is arguably the most intense it has been. With the capital required for hour-by-hour, stage-by-stage, job-to-job operations, reliability affects both time and cost. Yet many component suppliers grew to market-controlling proportions via simple "razor and blade" planned obsolescence replacement models. With lower commodity pricing, increased efficiency across the supply chain is required. Extending MTBM and MTBF can drive substantial time and cost savings. Extending Mean Time Between Maintenance (MTBM) Most frac service providers accept some basic assumptions about maintenance cost and intervals on valves and valve seats. To keep it simple, assume a fluid end pumps 10 hours/day for 20 days/month. In six months, this accumulates 1,200 pumping Flange flex stress

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