After the FRAC . . . Ashbaugh #1

By Drew Orient
Right from the beginning I need to say I am not a geologist or engineer. I admit I have been totally fascinated by being on the Asbaugh # 1 Marcellus well site just outside Knox off and on this past week observing the fracturing of the first horizontal leg.

Halliburton crews under the direction of Stone Energy’s well completion team headed by Jerry Holcomb Completion Superintendent worked around the clock from Friday afternoon December 17 till the early hours of Tuesday December 21st. They finished the final frac section at approximately 1:30 AM. in time for those on site to see, through a break in the clouds, the beginning of the lunar eclipse.
For the crews it has been long work days in adverse conditions and though the fracturing process is decades old, Halliburton pioneered the technology in the mid-1940s, their work is now the center of concern and controversy. Questions have been raised about the chemicals used in the process and injected into the ground. There is fear that ground water, often rural residents drinking water supply, can be contaminated and compromised by these chemicals. Some are concerned that the underground explosive charges used to make perforations in the pipe about the size of an adults little finger become errant and travel upwards through the overlaying strata, causing cracks to reach the ground water formations. Worse yet the pressures of forcing sand and water into the Marcellus shale formations could lead to fault shifts and possibly mini earth quakes.
On site engineers and crew members paraphrased comments include: “How do people come to believe such things when so much effort is exerted to avoid mistakes… control the process, using over fifty years of experience and constantly improved technology and systems,… to assure best management practices are achieved. What do they think we do out here, have no concerns for environmental safety, or peoples welfare,… we are concerned about possible pollution…it is our world too.”
It is acknowledged the deep seated opinions from so many sides indicate, there is major distrust of corporations, skepticism of technology, suspicion of the motive to make a profit, fear of complexity, and that rhetoric has more value than substance.
But at Asbaugh #1 this is what was observed. The well bore hole starts with a conductor pipe section and extends 56 feet. Inside this casing is 495 feet of surface casing extending through the freshwater, common groundwater zones. This is followed by 2500' of intermediate casing. Finally the production casing is placed all the way to end of the well bore including the horizontal leg. All casings and spaces between the pipes and the earth formations were filled using special expanding cement with gas stop. This was verified by on site engineers and PADEP inspection. It is asserted the cement circulates totally around the pipe and creates a gas and water tight bond. By the time the well is in production there will be three separate casing between the gas and the fresh water zones.
According to Stone Energy’s engineer on site Jerry Holcomb, who has 37 years in the Appalachian gas fields, “if properly installed it is nearly impossible for all casing and cementing to fail and allow contaminate of ground water”.
Mr. Holcomb also pointed out, Marcellus Shale is different from gas found in shallow formations that have been drilled for over 150 years. In these formations the gas is caught in voids or in sands. The Marcellus shale gas is a dynamic formation where over time organic material decomposed, creating the gas captured in the shale. The Marcellus shale in Clarion County is sandwiched between two layers of limestone the Tully above and the Onadaga below. The Marcellus lies over 5,000 feet below the surface.
According to a log of a nearby well, the Tully limestone directly above the Marcellus is over 75 feet thick. Limestone is a very dense, hard and normally non-fractured rock. Above the Tully is a shale rock layer over 700 feet thick. Between this shale layer and fresh water zones, at approximately 400 feet below the surface, or 4500 feet above the Marcellus, are 18 separate sand and shale rock formations and the last shale rock formation below the freshwater zones is over 500 feet thick.
The explosive charge that put holes in the pipe at Asbaugh #1 also sent finger sized cracks only 2 to 3 feet out into the Marcellus shale rock under the Tully. The Marcellus shale formation is estimated, from other sources, to be 80 to 100 feet thick. The majority of the charges were directed sideways and below the pipe downward toward the Onadaga. The Marcellus shale is naturally cracked with multiple micro-fractures.
Beginning Friday night the Halliburton crew under the direction of Mr. Holcomb began the frac, injecting a prescribed amount of sand, water and fracturing chemicals into the furthest 400 feet of the horizontal leg. They followed a fracturing schedule and composition developed by Stone Energy engineers after review of bore logs and seismic testing. During the next four days into each 400 foot section of the leg, 2,000 horsepower pumps and blending units injected under pressure over 300,000 gallons of water, and 300,000 pounds of sand.
Mr. Holcomb “explained the water is a carry agent used to transport the sand. The water pushes the sand through the holes of the pipe and out into the many micro fractures already in the rock. The water/sand opens the cracks and the sand is wedged by the water in between the thin layers of shale which ultimately liberates the gas.” In the water some chemicals are added to aid the frac process. All the chemicals used are now listed on the Halliburton web site. One is a friction reducer, so that the sand does not attach to the sides of the pipe, at 3/4 of a gallon to every 1,000 gallons,” or 225 gallons to every 300,000 gallons, or less than a 1/4 of a cup for every 15 gallons. The material safety data sheet (MSDS) lists this as hydrotreated light petroleum distillate. It may cause eye irritation...Mr. Holcomb remarked, “ it is similar to Pam cooking oil”.
The second additive is a scale inhibitor, called scale-check and needed to counteract impurities in the water. The water used was a blend of  stream water, recycled frac water from another well site, and water purchased from Knox Borough. The MSDS lists this as Ammonium chloride with no significant hazards expected. It is added at a rate of 1/4 of a gallon to every 1,000 gallons, or 75 gallons to every 300,000 gallons. less than 1/4 of a cup for every 50 gallons.
A third significant chemical is a biocide, added to kill bacteria naturally occurring in the water and sand. Bacteria can be problematic if they attach to pipe and fittings a mile below the surface. This one is called BE-9, and its chemical name on the MSDS is Tributyl tetradecyl phosphonium chloride. BE-9 may cause eye and skin burns, and respiratory irritation. It is added at the same rate as scale-check 1/4 of a gallon to 1,000 gallons.
The sand used at different mesh sizes also have MSDS sheets to warn of the dangers of its use in concentrated form. The full MSDS can be reviewed at www.halliburton/hydraulicfracturing.com. The sheets list precautions that need to be taken when handling the chemicals in concentration. Halliburton has become responsive to the public request to know what is in their frac mix. They have focused on Pennsylvania as the first state since fracturing blends change with geology and geography. They have also announced a new fracturing formulation called CleanStim, using materials sourced entirely from the food industry and replacing the biocide with ultraviolet light. It will be important to see how and when these changes reach the field crews.
After each frac section was completed a specially designed composite plug was inserted to prevent flow back of the water and any gas. The blending of chemicals, the flows of water, injection of sand, were all monitored by redundant computer systems and crew teams. With the completion of the last section a feeling of satisfaction permeated the control trailer as the last hoppers of sand emptied, and the crew  talked of lunar moments and being off for Christmas.
By Wednesday afternoon nearly all the Halliburton trucks and equipment were gone from the site and a new team arrived and taken their place. A crew from Weatherford Corporation is now on site and responsible for well clean up, and installing the well production tree, the system of pipes and valves ones sees on the surface, the size of a large outdoor Christmas tree. The special well tube to the last plug and top seal are in place. These will enable Weatherford to control flow back pressure and conduct production testing. Weather-ford will begin the water recovery process returning the flow back water, which could be up to a million gallons, into the battery of storage tank trailers at the well. The water flowing back from the well in turn Mr. Holcomb said “will be pumped into tank trucks and taken to a treatment facility, most likely The Brine Plant in Franklin, PA. No flow back water or later production water is allowed to be stored in the pond on site, that requires a separate permit.”
As Weatherford removes the water from the well, the expected captive gas will also begin to flow pushing the water ahead and later with it. As the combined gas and water reaches the surface, the gas for safety reasons will be ignited and flared possibly lighting the night sky as early as Christmas Eve.The Progress News welcomes comment and visits to our website myprogressnews.com.