PITTSBURGH -- The Utica is the oldest active major shale play in North America. Eastern Ohio was once a shallow, warm water shelf environment with early marine life forms that generated all T-I and T-II kerogens, which is the best organic material and makes up the Utica-Point Pleasant shales, said Stuart Maier, vice president, geosciences, Gulfport Energy Corp.

Speaking at Hart Energy’s DUG East Conference on June 4, Maier described the depositional environment for the shale. “It was isolated, pretty much closed in, oxygen-starved and not a lot of circulation. [Being oxygen-starved] is really key to the preservation of organic matter for subsequent burial and thermal maturity.”

Along with other operators, Gulfport is now using science to unravel the optimum development strategy for this play. As he noted every play is different, and the companies are working hard to answer the biggest questions in optimizing development in the Utica-Point Pleasant shales: frack design; well spacing, lateral length, lateral orientation; and production rates.

“These are all dependent variables. I’ll emphasize that you can’t look at one variable without looking at the others. These are all interrelated. The result of that is this is a very complex problem. You have lots of data that goes across disciplines,” he explained. “All the working disciplines–engineers, geologists and petrophysicists–have to work together to answer these questions.”

Starts With Geology

The key factors for the Utica-Point Pleasant shales are the shallow, warm waters and multiple sediment sources that were oxygen deprived. For the multiple sediment sources, there were clastics coming in, carbonate debris coming in and the deposition of organic matter, Maier continued.

“Couple that with rising and falling sea levels and you’ve got interbedded sand and shale sequences both macroscopically and microscopically,” he added.

In describing a photograph of cores, he pointed out that macroscopically the cores are extremely stratified with respect to the major rocks. Even on a microscopic level, the cores are stratified with fossil debris sitting on top of detritus that is on top of carbonate fossils.

In looking at the mineralogy of one of the shales, there are carbonate grains, some fossil debris, quartz grains and dark areas that are basically organic matter with a little bit of clay. He emphasized that there is a tremendous amount of particles of organic matter. The nature of the particles is important on a micron scale.

“The pore network for the Point Pleasant is primarily in the kerogen particles, which create the network. The spaces are about two microns across. Looking at various sizes of pore throats compared to the approximate size of the largest molecule of oil shows plenty of room in the pore spaces,” Maier said.

“What the organic pore network looks like is a very small, delicate selection of pore throats that form the network. These are very well connected. The network does have high tortuosity and does have very restricted flow, which are challenges,” he continued.

Learning Curve On Darla Pad

“Gulfport entered the play in late 2010 and on a leap of faith stepped into it. So far it has paid off. Currently we have 179,000 net acres in the play and seven active drilling rigs,” he said.

Although the company has some of the highest initial production rates in the play, it has a long way to go to determine the optimum frack design, lateral length and lateral spacing.

“What we’re doing to address this is on our Darla pad, where we’ve constructed a geomodel. We are going to do microseismic when we frack the wells and run chemical tracers. We’ve run optic fiber along the outside of the casing on three of the wells to monitor fluid flow. We are also going to run some production logs to see how the various zones contribute,” Maier explained. “The three Darla wells are built in a fan pattern to really monitor the effect of well spacing along those laterals.”

The well pad will be used to identify where each cluster is located in the Point Pleasant, monitor the frack job with fiber optics and see how many clusters per stage are effective. One of the variables the company looks at is the kind of rock where the frack is initiated.

“We will monitor the frack jobs of one of these wells to see which perf clusters take fluid. That is one of the big questions – what is your perf cluster efficiency? How many perf clusters and stages are you effectively treating?” he asked. “We should be able to find that out.”

In the Utica, the company expects to drill about 80 wells in 2014, which is about a 25% increase over 2013. Gulfport is still very early in the play and has a lot of work left to do and a lot of science yet to gather.

“We feel we have a very good asset in the Utica, and we want to exploit it. We do have capital available, and we’re going to put it to the best use for our stockholders,” Maier said.

Contact the author, Scott Weeden, at sweeden@hartenergy.com.