Caterpillar Global Petroleum has developed a dynamic gas blending (DGB) retrofit kit for use on the Cat 3512C (HD) engine for well stimulation applications. “Our frac system is going to be able to substitute up to a little over 60% of the diesel fuel with natural gas,” said Scott Roberts, Caterpillar Global Petroleum well service product marketing manager in an exclusive meeting with Drilling Contractor. The system is capable of achieving maximum substitution at various speeds between 1,400 and 1,900 rpm and above 20% engine load over the full operating range.
Along with significant fuel cost savings by substituting diesel fuel with natural gas, operators can run the system with CNG, LNG, as well as field gas with a lower heating value between 850 and 1,250 Btu.
“It can detect the changes in the fuel quality and adjust itself without someone having to go fix settings or recalibrate anything,” Mr Roberts said. “Most importantly, we can do all this while maintaining the Tier 2 emissions that the engines have already been certified to.” A combined muffler and Cat Diesel Oxidation Catalyst included in the DGB kit help the engine sustain US EPA Tier 2 level emissions.
The DGB system is fully integrated with the engine control system, optimizing engine performance and ensuring that the engine always operates within safe parameters while blending diesel and natural gas.
Caterpillar introduced its Cat DGB system for land drilling and production last year at OTC. The latest system Cat 3512C (HD) engine will be commercially available in June 2013.
Cat is a registered term of Caterpillar.