“Today’s oil and gas drillers care less about cost and more about value,” said Kevin Mallin, an internationally respected consultant in deep hole drilling, during a seminar for Atlas Copco sales and service reps. Mallin selected the words carefully, clearly articulating the bottom line of deep hole drilling businesses: “They want to drill smarter.”
The oil and gas course was directed by Mike Millsaps, who oversees sales, marketing and service of Atlas Copco deep hole drilling tools for all of North and South America, with worldwide responsibility for oil and gas equipment in particular. The course’s field visits were coordinated with help from Luby’s Equipment Services in Heber Springs, Arkansas, and Southwestern Energy Company from Houston, Texas.
Though the oil and gas market varies from country to country, the concerns facing drillers are universal. So Atlas Copco customer centers on four continents sent 23 enrollees to the course, who came from the United States, Poland, Ukraine, Chile, Tanzania and India. The instructors came from the U.S., England and Sweden.
Three full days of training and two site visits hosted by Southwestern Energy in the Fayettville Shale play underscored Mallin’s message: smarter deep hole drilling means acquiring “additional skills, such as knowing when to drill with air and when to use rotary in the same hole.” Relying on a single drilling technique is a thing of the past.
Mallin pointed out that although the class was really about fundamentals of deep hole drilling common to all deep hole applications, defining “deep” as greater than 300 meters, or 1,000 feet. This includes water wells, geothermal power production, coal seam gas, carbon sequestration and mineral exploration. Geological stratification typically requires different kinds of drilling at different levels, no matter what the application.
Mud, rotary or hammer, presets and more
Before the course’s conclusion Millsaps showed how Atlas Copco’s range of DTH equipment provides deep hole drillers what they need to stay competitive in today’s market. The long list included drill rigs, mud pumps, compressors, drill pipes, collars, and stabilizers, hammers and bits, tricones and many more.
Mallin also taught the class that advancements in drilling fluids and additives make it increasingly beneficial to distinguish “drilling fluid” in their vocabularies from the term “mud.” Understanding the characteristic differences between mud and various polymer-based drilling fluids gives deep hole drillers a wide range of hole wall and well pressure control, in addition to maintaining drilling performance as it varies with depth and formation changes.
Josh Marcus, an Atlas Copco DTH product specialist who works directly with Millsaps out of the deep hole tools research and development center in Roanoke, Virginia, updated participants on the function and capabilities of today’s new hammer designs. Depending on the hardness of the formation, hammers are two to five times faster in rock than rotary, with the hammer’s advantage greatest in the hardest rock formations. One example he gave was a company that had spent two weeks drilling a hole with rotary. A neighboring hole with a DTH hammer took only 10 hours.
Marcus challenged two of the long-held perceptions of hammers. First he assured the class that hammers can indeed drill with certain polymer-based drilling fluids (not bentonite mud), and companies have now been successfully demonstrating the ability to turn corners with hammers at the kicking point, as well as drilling laterals. The availability of jet subs and hydrocyclones further expand the versatility of hammers for deep hole drilling.
Before making two Southwestern Energy (SWN) drill-site visits, the group stopped at the Luby’s Equipment Services–Oilfield Division shop in Heber Springs. Store Manager Gene Chandler gave them a tour during which they watched technician Josh Dill service a hammer and received hands-on instruction of the Atlas Copco R4 bit retrieval system by Millsaps himself.
SWN utilizes what they call a “spudder” rig concept in their Fayetteville Shale operations. They use a smaller, air drilling rig such as an Atlas Copco RD20 rig to drill the upper, vertical portion of a well. This works well in the Fayetteville Shale as this portion of the well goes through hard (sandstone) rock.
The spudder hole is drilled to a total depth near the base of the hard rock and the top of a large shale section where the hole is loaded with drilling fluid and a wellhead cap is installed. The spudder rig TD ranges from approximately 2,000 feet to approximately 5,000 feet depending on what part of the play it is located. The RD20 is then moved off the well and a larger “re-entry” rig is later moved on the well to perform directional drilling. The well is at or near kick-off point, the depth where the curve section of a horizontal well begins, when the re-entry rig moves in.
The first of the site visits was to a spudder rig pad where an RD20 rig, operated by Pense Bros. Drilling Company, was working. Pense Bros. is a drilling contractor that specializes in air drilling for natural gas and oil throughout North America.
The participants, who had studied well design in the classroom, now had a practical laboratory. The well plan called for a 12.45-inch diameter hole to be drilled to 1,000 feet and 9 5/8-inch surface casing to be cemented in place. The surface casing was then drilled out with a 8.875-inch bit with the hole size reduced to no smaller than 8.75 inches at “spudder” hole total depth.
The second site visit took participants to a pad in its second stage of drilling, demonstrating the operations of what SWN calls a “re-entry” rig. Here a conventional electric triple derrick rig operated by DeSoto Drilling Inc., a subsidiary of Southwestern Energy Production Company, was in the process of drilling the curve section of the well, gradually building the inclination to 90 degrees. Once the inclination was built to 90 degrees, the horizontal, or lateral, section of the hole was drilled. Most SWN well site pads in the Fayetteville Shale accommodate multiple horizontal wells.
Usually two or more wells are drilled by a rig each time it is moved to a pad. The re-entry rig visited had a walking system which allowed the rig to move itself hydraulically from well to well without having to lay down the derrick or drill pipe. This allows for a quicker and less expensive move of the rig from one well to another on the pad. It usually takes from six to 10 days for a re-entry rig to move on a well, drill the 8 ¾-inch curve and lateral hole sections, run 5 ½-inch production casing, cement the casing and release the rig. Total depth of Fayetteville Shale wells range from 5,000 to 13,000 foot measured depth and lateral lengths range from 2,500 feet to 8,500 feet.
Participants also learned about a stage of well construction, called hydraulic fracturing, which occurs after the well has been drilled and cased and does not necessarily involve a drilling rig. Shale wells almost always require hydraulic fracturing to allow them to flow, due to their very low permeability.
Cullen McGinty of Atlas Copco’s Rocky Mountain store in Commerce City, Colorado, said of the course, “It was perfect for me, connecting the dots and giving me a more complete picture of our roles with the distributors and their customers.”
Simon Romli of Atlas Copco Tanzania’s customer center, who specializes in rock drilling tools, said, “Now I know what is meant by ‘deep hole’ drilling. He said now that he knows what is needed, he will take back technical options to his customers, who work in a country that is just learning its potential for oil and gas production. He also appreciated the network of expert support the course introduced to him.
In addition to deep hole drilling fundamentals, well plans, casing types and fluid drilling, the course included an introduction to Atlas Copco Hurricane air and nitrogen booster compressors by engineers Maynard Jones and Pieter Taljaard.
Alex Grant, product manager for Atlas Copco well drilling equipment, outlined drilling rigs used for deep hole drilling. He explained why the Atlas Copco RD20 has been a rig of choice for the vertical part of gas and oil wells, highlighting its crane carrier with heavy duty I-beam construction, the 380 horsepower engine that get it to, on and off a pad quickly, and its unique feed system. The load is always on the cylinder, not the lattice tower, placing the 120,000 pounds of pullback on four solid points of contact. Other manufacturers competing with the RD20 in this class, he explained, have cantilevered designs, which project back from the rig. They do not provide such solid, centered support.
Ron Boyd, the project manager for Atlas Copco Secoroc oil and gas division, as well as the EDGE drill monitor, and Bjorn Samuelsson, training manager based out of Atlas Copco Secoroc distribution center in Fagersta, Sweden, led class discussion on market offerings and how the Atlas Copco brand stands out for customers as a greater value, returning the class to Mallin’s point that deep hole drillers are looking for a smarter way of drilling.
Two smaller oil and gas seminars have been held in the past. This was the first time the course was held in Little Rock. Plans are to continue to offer the course as an annual event.