Southwestern-DeSoto Named as Drill Rig Customer in Arkansas:
$100,000 Worth of Fuel Saved in the Fayetteville Shale in 45 Days
Caterpillar is stepping up promotion of its Dynamic Gas Blending technology allowing heavy duty engines to run on a money-saving combination of conventional diesel and variously sourced natural gas. Caterpillar has named Southwestern-DeSoto as a drill rig customer running DGB-fitted 3512C generator sets in Arkansas, and says it’s likewise shipped kits for 3512Cs for well stimulation – aka hydraulic fracturing.
Southwestern Energy’s SWN Drilling Services unit installed two Cat 3512C gensets with DGB on a rig operating in the Fayetteville Shale, where the units “powered the drilling of eight wells over the course of 45 days saving Southwestern Energy greater than an estimated $100,000 in fuel costs.”
Key factors in realizing these savings, Cat says, were 100% availability of gas and no increased unexpected downtime.
“If we can keep natural gas utilization at current levels, we believe we are looking at about an eight-month pay back of investment,” SWN Drilling VP Marty Carley says in the Caterpillar announcement. “This is taking into account the cost of building and maintaining a scrubber skid and all the natural gas lines required to hook the system together.”
Installation proved “seamless,” Cat says. “For us the DGB system was as easy to operate as hooking up a gas line,” Carley said. “Nothing else changes in set-up, operating or engine maintenance with the exception of changing gas filters and right now we are expecting to do that about every six months. Set up after rig move is easy as well, with a scrubber skid moved to the location prior to the rig’s arrival.”
Cat Keeps the Regulators Happy, Even for Field Fix
Besides having U.S. EPA approval, the Cat DGB system is California Air Resources Board-certified for fuels with a LHV/lower heating value of between 905 BTU/scf to 1,250 BTU/scf, “giving operators a wide range of fuel options while meeting Tier 2 emission levels.
“Additionally, the Cat DGB system was recently approved by the EPA as a field fix that allows the installation of the DGB kit to convert the diesel engine to run on a combination of diesel/natural gas. This field fix was approved and implemented in accordance with 40 CFR Part 89 and Circular 2B dated March 1975. The EPA approval applies to the DGB kits for land drilling and well stimulation applications.
“For Southwestern, CARB certification proved to be a key differentiator,” says the manufacturer. “Maintaining OEM emissions certifications is really important to us.” said Carley. “It is critical that we stay within the guidelines and preferable that we’re exceeding them.”
‘Value and Flexibility’
“We believe in the value and flexibility the DGB system provides,” Caterpillar Oil and Gas account manager Derek Kamp says in the SWN-DeSoto announcement. “We’re pleased with the successful performance of the DGB for Southwestern Energy and have come to expect nothing less than stellar results from our dual fuel solution based on land drilling, production and well stimulation installations for numerous customers around the globe.
Good for Us All
Carley too talks up fuel flexibility. “We believe the diversity of this system to run on a blend of natural gas and diesel or on straight diesel is a critical factor in our operation,” he said. “Having the ability to mitigate the downtime created by either natural gas fuel (CNG, LNG, and field gas) availability and or natural gas fuel quality allows us to maintain the logistic diversity of the rig, if these issues arise.
“When natural gas fuel is available, we are playing a part in increasing the demand for this natural resource and this is a win, win deal for us. The flexibility of these DGB systems increases our ability to utilize a wide range of natural gas fuels, while at the same time staying fully operational regardless of the type of fuel available.
“Increasing the demand for natural gas is something everyone involved in this business should be aware of and working towards.”
Separately, Caterpillar said that it has commenced full production of DGB retrofit kits for Cat 3512C (HD) engines for well stimulation, “and has shipped the first kits to customers.” Kits are available to order through Cat dealers. “This system will allow for maximum substitution of diesel fuel with natural gas during high pressure pumping operations,” Cat says – up to 70% replacement of diesel with gas.
The EPA-approved DGB kit is available in both Air To Air After Cooled (ATAAC) and Separate Circuit After Cooled (SCAC) configurations for 2,250-horsepower and 2,500 horsepower 1900 rpm ratings. The EPA approved DGB kit maintains diesel performance levels with up to 70 percent replacement of diesel with gas.Contact information is only available to premium subscribers. Click here to purchase a premium subscription.
Source: Caterpillar with HHP Insight follow-up