Due to the fact that wells can be drilled through more feet of  pay zone, and the fact that Sugarkane exists in the “sweet spot” of the Eagle Ford shale, (over-pressured, and containing large volumes of oil and natural gas liquids), it is proving to be a hot area of the overall play.  Aurora Oil and Gas Ltd, an Australian company, (With Marathon Oil as operator) will have drilled over 85 wells in the Sugarkane field by the end of 2011. Aurora  expects to ramp up their drilling program in 2012, running 10-12 rigs with 4 frac crews, and drilling 123 wells by year’s end. Aurora operates in 4 separate AMI’s or “areas of mutual interest” in the Sugarkane field, identified as Longhorn (28,280 gross acres), Sugarloaf (23,550 gross acres), Ipanema (4,600 gross acres) and Excelsior ((20,180 gross acres).

Players in the Sugarkane Eagle Ford shale play include Aurora Oil and Gas Ltd., Marathon Oil,  Pioneer Natural Resources, ConocoPhillips,  EOG Resources, Empyrean Energy, Eureka Energy, Geosouthern Energy, Murphy E&P, Petrohawk Energy among others.

The Sugarkane Eagle Ford shale trend runs roughly from Live Oak to Dewitt county.  Below is a map of the Sugarkane Eagle Ford shale play. (source: http://www.auroraoag.com.au)

The second illustration shows Aurora Oil and Gas’s completion procedure for wells in the Sugarkane field and how water aquifers are protected from contamination by frac fluids.

“The bottom line here is that our confidence in individual well results and the total 900 million barrels of oil equivalent net after royalty reserve estimate, have increased since our April analyst conference. Because this is such a huge net oil accumulation, and I believe investors have undervalued this asset,”

Mr. Papa discussed how the Eagle Ford shale play is divided into the “East” and “West” areas, with Eagle Ford shale wells in the East such as the Harper #1H producing an initial production amount of 1,070 barrels a day, and the  Cusack – Clampit wells, at rates ranging from 860 to 1,800 barrels of oil per day, with 1 to 1.8 million cubic feet a day of rich gas each. In the Eastern Eagle Ford shale, the play is divided into two zones at different depths and the rock is thicker.   In the West, Eagle Ford shale wells such as the Haynes 1-H north of the town of  Tilden, in McMullen county, are producing in the 970 to 629 barrel per day range. There in the Western Eagle Ford shale oil window, the rock is a bit thinner but laterals are being drilled up to 6000 feet to increase production.

Also notable in the EOG conference call was a revelation about the mechanics of ultimate oil extraction from the formation.  Some geologists had at first doubted the ultimate recovery of Eagle Ford shale wells. Because the Eagle Ford shale is a “borderline carbonate reservoir” and not a traditional shale, there is a good amount of flow through the matrix of the rock itself.  The reservoir is proving to have much of the same qualities as a carbonate reservoir for ultimate recovery of oil.

In layman’s terms, a carbonate oil and gas reservoir is typically a much more porous and easily drained type of rock than shale when it comes to oil and gas. Carbonate rock such as limestone may have channels formed by acidic liquids, natural fracturing, etc, which allow oil and gas to flow through the rock to the wellhead.  See image below:

Many of the world’s largest oilfields such as some in the Middle East are carbonate reservoirs, drilled with vertical well technology. Shale on the other hand is a harder and mostly nonporous rock which requires much hydraulic fracturing before anything will come out of it. What exists in the Eagle Ford shale, is something in between. The fact that wells can now be drilled sideways using horizontal drilling and then hydraulically fractured, has made possible a  new frontier  when it comes to taking advantage of borderline rock such as exists in the Eagle Ford shale.

On a more technical level, Papa discussed the “bubble point pressure” of the Eagle Ford shale. “There is an extraordinarily high differential between the initial reservoir pressure and the pressure at which solution gas breaks out of the oil, technically called the bubble point pressure. Across our acreage, the original reservoir pressure averages 7,200 psi and the bubble point pressure averages 2,500 psi. This unusually high spread provides for a larger-than-normal fluid expansion recovery factor. That’s why we’re so confident with our 0.9 billion barrel reserve estimate.”

So far the company has had 100% success across an 120 mile window stretching from near Cotulla, TX to Gonzales county. Wells are being fracked in packages, as opposed to fracking just one well, and there have been some delays in getting the required amount of equipment to move forward  at the desired pace.  This has slightly reduced the amount of oil the company has expected to bring online in 2011 but is seen as an issue that will be overcome but not until mid 2011.

How many Eagle Ford shale wells will be drilled? With a proposed Eagle Ford shale well spacing of somewhere around 80 acres, (more in the west), there are going to be a lot of wells drilled in EOG’s Eagle Ford shale acreage. It may take a lot fewer to produce the .9 billion barrels as was first estimated according to Papa. They had initially given a figure of 2,800 wells to achieve .9 billion barrels of Eagle Ford shale oil production in their leasehold area.

Below, a photo of the Haynes 1-H, an Eagle Ford shale well drilled by EOG Resources in McMullen County.

Above, a photo of an EOG Resources Eagle Ford shale well, the Haynes 1-H, in McMullen County Texas, north of Tilden.

Eagle Ford Shale Oil Potential Greater Than Bakken Shale

The Bakken shale in North Dakota, which thus far was considered the largest new oil discovery in the United States, at around 5 billion barrels of recoverable oil, may pale in comparison to the Eagle Ford shale.

EOG Resources  has estimated their own Eagle Ford shale holdings at 900 MMBoe*  (nine hundred million barrels of oil equivalent)  in the roughly 550,000 acres they hold in the oil and “wet gas” windows.  “This figure, stated in “barrels of oil equivalent”, consists of an estimated 690 million barrels of oil, 100 million barrels of natural gas liquids, and 661 Bcf of natural gas.  That’s “net after royalty” meaning you can add about 20-25% more to that figure for another 180 MMBoe  of recoverable hydrocarbons.  There, in just a fraction of the Eagle Ford shale you get over one billion barrels of oil equivalent, most of it liquids.  McMullen county alone is comprised of 712,320 acres. Much of that county lies in the oil and “wet gas” windows.

Petrohawk Energy has reported that in the 360,000 acres they hold, 225,000 are in the oil and  wet gas windows of the Eagle Ford shale, and have the potential to produce 340 million barrels.  That’s 1,511 barrels per acre of liquids for Petrohawk Energy and 1,782 barrels per acre (net after royalty) for EOG Resources.  Let’s just take a look at the map below and do a very rough estimate.

Map from EOG Resources

Take LaSalle county for example, (where the Hoff #4H is located above), which consists of 956,800 acres. Of that, roughly half is in the oil window, and the other in the wet gas window. EOG Resources recently drilled a series of delineation wells, as seen above, and has estimated that the potential of oil and gas production over a 120 mile swath of South Texas is fairly consistent.

Just for fun, if you take an area of roughly three LaSalle counties in the oil and condensate window of the Eagle Ford shale, or 2,870,400 acres, and multiply that number by the average barrels per acre that has been proposed by EOG and Petrohawk, or 1,646 barrels of recoverable crude (net after royalty), per acre, and multiply that by 2,870,400, you get 4,724,678,400 barrels of oil.   That’s about 4.7 billion barrels, or roughly as much oil as remains in Alaska.  Pioneer Natural Resources believes the Eagle Ford shale contains as much as 25 billion barrels of  recoverable crude and natural gas liquids. This is much higher than the amount estimated by the D.O.E. and others, which is around 3.35 billion barrels. FBR Capital, a financial research firm, reported in August of 2011 that “worst case” the Eagle Ford shale holds 7 billion barrels of oil. On the high side FBR estimates it holds as much as 20 billion barrels. These numbers could be revised upwards as new drilling and production methods are developed.

Now look at the chart below, showing remaining U.S. reserves.

Update: At the recent Developing Unconventional Gas (DUG) Eagle Ford conference in San Antonio, Pioneer Natural Resources offered a presentation that suggested that the Eagle Ford shale contained as much as 150 trillion cubic feet (Tcf) of natural gas and 25 billion barrels of recoverable liquids including crude oil and condensate.  Referring to the economic impact of the Eagle Ford shale on South Texas, Pioneer Natural Resources CEO Scott Sheffield added the following comment.   “When you have a 25 billion barrel play in south Texas, just the amount from severance taxes on oil and condensate and NGLs – the amount of ad valorem taxes that goes into hospitals and schools – that’s a tremendous boon to the economy of south Texas,”

Right now, according to these  estimates, there is more oil in the Eagle Ford shale as exists in all of Alaska. There’s more than in the federally controlled offshore areas, California and the Permian Basin. On the high side, there is possibly more oil in South Texas than in ALL of the conventional oilfields shown in the graph above!   FBR Capital estimates the Eagle Ford shale is the largest discovery of natural gas ever found in Texas, at around 200 trillion cubic feet, which would supply the United States needs for over ten years. Are you like me and are wondering why this huge discovery is not front page news across the nation?

* BOE or barrels of oil equivalent assumes that one 42 gallon barrel of oil is equivalent to 5,800 cubic feet of natural gas. The term BOE is used liberally by companies with acreage in areas of the Eagle Ford shale which contain more oil than natural gas. Most companies with liquids rich holdings will break their estimated reserves down into oil, NGL’s and gas for investor presentations.

Update: Just when you thought it couldn’t get any better in terms of new oil discoveries in the United States, along comes a potential 25 billion barrel discovery in Ohio. See Utica Shale

Article by EagleFordShaleBlog.com author Nolan Hart, August 12, 2010

Original Post:

EOG announced in a May 4th, 2010 webcast that they are planning a major oil and gas seismic survey for this summer and fall that will stretch across their 120 mile long lease area in the oil and condensate window of the Eagle Ford Shale. It was stated in the webcast that the current drilling program would be “moderated” until the results of the seismic survey in the Eagle Ford shale leasehold area was completed and fully analyzed. Investors were told not to expect any more “constant Eagle Ford news flow” until later in the year. The geophysical seismic study should take most of the summer to complete and we could possibly be seeing a very big drilling program by EOG starting in the Eagle Ford shale oil window this fall. In the past investor presentation they announced that “major production would come online in 2012″.

The only way for major Eagle Ford shale oil production to come online is for utilizing more than just six rigs, as they are presently running. Previous statements have indicated that EOG may try rotary steerable technology and multi well pads for maximum efficiency.  Current rumors in the oil patch are that they are planning a 25 rig program for this coming year.

One thing is certain and that is after paying up to $2000 or more an acre, EOG wants to hold on to much of the 505,000 acres in the oil window of the Eagle Ford shale as possible and they will have to drill quite a lot of wells in the coming three years to accomplish that, since most  of the lease terms are for that long.  Granted that many of their leases are large ranches and for many oil and gas lease contracts it only takes one well to hold the lease, but they have also leased scores of smaller parcels, down to only  a couple of acres.  The cost of losing these very small leases will not hurt them that much, and renewal offers can be made to hold them, but my guess is that EOG will start first with the larger ranches where the new Eagle Ford seismic survey data shows the best prospects and then move to drill on the smaller parcels toward the end of their three year term expiration dates. I suspect that we are talking about more than two dozen rigs running when EOG ramps up their major Eagle Ford shale drilling campaign in late 2010 and into 2011.

Oil and gas seismic survey leasing is already underway in McMullen, Dimmitt,  LaSalle, Atascosa, Karnes, DeWitt, and many other counties. If you or your neighbors have signed a lease with EOG you should be getting a call regarding permission to do an oil and gas seismic survey on your property.  For an overall picture of the entire EOG Eagle Ford shale oil and condensate window lease area, the seismic survey will be done on as many parcels as they can obtain permission for, regardless of whether they have been leased for Eagle Ford shale drilling rights or not.

What Landowners Should Consider

If you have already leased your land for Eagle Ford shale drilling I see no problem with allowing a seismic survey to take place. Here’s the dilemma facing landowners who have not already leased their property for Eagle Ford shale drilling. Should you let oil and gas companies such as EOG hire  contractors to come onto your land and use 3D seismic technology to see what is under your property for the cost of a few hundred dollars in surface damages?  This would be like allowing the person you are playing poker with peer over your shoulder and see your cards before a bet is made.   EOG could even sell the results of the seismic survey  to other oil and gas companies looking to lease Eagle Ford shale acreage that EOG has deemed unworthy.  I think it would be wise to contact an oil and gas attorney before allowing any seismic survey of your land, especially if you have not signed an Eagle Ford shale lease yet.

Nolan, May 14, 2010

See updated info above.

The size of an oil or gas play may be only a few hundred acres or as is the case with the Eagle Ford shale, Haynesville shale, Barnett shale and Marcellus shale, cover hundreds of thousands of acres over a wide region.

A shale gas play, such as the ones mentioned above, is simply a discovery of oil or gas in shale rock that is significant enough for oil and gas companies to launch a campaign of leasing and subsequent exploration. In the case of the Eagle Ford shale it is turning out to be both a shale gas play and and oil play.

What Is Shale Gas?

Shale is a sedimentary rock that is generally formed as particles of sediment settle out in calm water. Shale can be formed in shallow inland waters or deep ocean basins. Many of the shale formations in the United States, such as the Marcellus shale, were formed during the Devonian period, around 390 million years ago.

The rock found in the Eagle Ford shale, which is the focus of this blog, was formed in a marine environment during the Cretaceous period, approximately 145 to 65 million years ago. It was during the Cretaceous period, following the Jurassic period, that many of the worlds limestone formations were laid down. Cretaceous literally means “chalky”, taken from the German word for chalk,  Kreide. The Cretaceous period was a time of warm climate and high seas. During the Cretaceous period billions of tons of CO2 were “sequestered” by marine organisms and eventually returned to the earth in the form of sediments.

Shale rock is generally high in organic content. Once covered up by other sediments and buried over millions of years, heat and pressure begin to work on these sediments and oil and gas are formed. Some of the oil and gas may begin to migrate upwards, to layers of sandstone and porous limestone where it becomes trapped. These are considered conventional oil and gas reservoirs and shale is often the “source rock” or original source of the hydrocarbons. In some cases, as in the Eagle Ford shale play, a significant quantity of oil and gas remain in the shale rock. Natural gas and oil that occur in shale are called “unconventional”.  Now with new horizontal drilling and hydraulic fracturing methods it is possible to extract that oil and gas. “Unconventional” gas is quickly becoming the new norm.

The illustration below shows how South Texas looked during the Cretaceous. It was covered by shallow warm seas. It was during this period that the Eagle Ford shale was deposited.

Below is an illustration of what a shale formation looks like underground and how a horizontal well is drilled.

Shale gas, from rock formations such as the Marcellus shale, Haynesville shale, Barnett shale and now the Eagle Ford shale, is an important energy resource for the United States. Now thanks to these “discoveries” or moreover the advances in technology that make recovery of oil and gas from shale possible, we have over 100 years worth (and growing) of natural gas supply in North America. Hopefully our elected officials will wake up to this new reality and quit wasting our tax dollars on things like corn ethanol and “clean coal” and instead focus on converting our vehicles and power plants to use abundant natural gas.

Article by Nolan Hart

Here is a good book to get if you are considering leasing your land for oil and gas exploration. It’s not cheap but could save you thousands in the long run.

The name of the oil and gas play is frequently misspelled as “Eagleford”. The correct spelling is what is seen on this website.   The Eagle Ford shale takes it’s name from the small town of Eagle Ford Texas, where it outcrops in North Texas near Dallas.

The following map is from Ross Smith Energy Group . They do not sell maps to the public.  It appears here with their permission.   This Eagle Ford shale map shows the trend from Mexico (where it obviously continues across the border as well) to East Texas. It shows the low pressure, oily section in the northern region, the condensate section in the middle and the dry gas section at the lower half. Although it is difficult to read the gray areas are Austin Chalk producing areas. Wherever you find Austin Chalk production you are likely to find Eagle Ford oil as well.

Here is a map from EOG Resources showing the oil, gas and condensate zones of the Eagle Ford Shale as well as some initial production rates. (Note, IP, or initial production rates should not be confused with long term production rates). You can click on the map for full size.

Below is a map from the U.S. Energy Information Administration. The map is a little out of date when it comes to showing well locations, since dozens of new Eagle Ford shale wells have been drilled since it was made. It does however provide a good picture of Eagle Ford shale thickness and extent.

The following Eagle Ford shale map from the Texas Railroad Commission shows counties with permitted and completed wells as of August, 1, 2011.

Below is an Eagle Ford shale map showing the depth of the top of the formation.

Below, Eagle Ford shale thickness maps from Petrohawk Energy. Thickness in feet of the Eagle Ford shale in Atascosa, Gonzales, Wilson, Karnes and DeWitt counties is shown.

The map below, from Marathon Oil, shows the Eagle Ford shale divided into four zones, dry gas, wet gas, volatile oil and black oil. While the distinctions between “black oil” “volatile oil”, condensate and “wet gas” are something even petroleum engineers can’t seem to agree on, basically “volatile oil” is lighter oil that evaporates faster than heavier crude. Lighter crude oil (higher API gravity) typically trades at premium prices since it is more easily refined into gasoline, etc. Marathon Oil purchased the acreage shown in blue from Hilcorp Resources Holdings for approximately $20,000 an acre.

The Carrizo Wilcox aquifer is an important source of water for much of the area where the Eagle Ford shale lies, and a primary source of frac water used in completing wells. Below is a map of the Carrizo water sand.

Below is a chart showing the Cretaceous geology of South Texas, including the Eagle Ford shale formation. The Pearsall shale is located deeper than the Glen Rose formation at the bottom of the chart.

Below, The first Eagle Ford shale well near Fowlerton in the old Naylor and Jones Survey.

The Naylor and Jones Unit 86, #1H is the first permitted Eagle Ford shale well within 10 miles of Fowlerton Texas..

A Brief History Of Fowlerton Texas.

At the turn of the twentieth century a couple of shrewd businessmen, the Fowler brothers, decided to form a land company and promote the dry, cactus and mesquite covered country along the Frio river in LaSalle and McMullen counties as the “Wintergarden”. They attracted well over two thousand buyers, many of whom migrated from the East Coast for the chance to own a plot of fertile farmland for a few dollars. A farm could be had for as little as twenty five dollars down and ten dollars a month. Many have called the brothers “swindlers” but some historians maintain that they did have a vision of the area as a farming utopia. The Fowler Brothers happened to tour the  country just prior to their development plans, during one of the “wet” cycles, when almost any crop could grow there.

Below is an advertisement that appeared in a 1913 edition of the “Fowlerton Reporter” for the First State Bank Of Fowlerton Texas. Like most of the buildings in the town of Fowlerton, nothing remains today.

Photo Of The First State Bank Of Fowlerton Texas

History of Fowlerton Texas And The Naylor And Jones Land Company

Two brothers with the surname of Dull, who had made their fortunes in Pittsburgh, PA, once owned the vast 400,000 acre Dull Ranch. The Dull brothers later sold 240,000 acres to B.L. Naylor and Judge A.H. Jones.  Naylor died in 1910 and Jones in 1912. Jones had contracted with the Fowler Brothers to develop 100,000 acres around what would eventually become the town of Fowlerton, Texas. Growth of the town really took off in the years between 1913-1915.

The Fowler Brothers, in conjunction with Naylor and Jones Land Company, laid out the town  they named after themselves on a grid system and over two hundred miles of roads were built. Lots were divided up, some as small as a sixteenth of an acre in the town-site,  as well as numerous farm plots of anywhere from an acre to a hundred acres or more. When someone bought a ten to 160  acre tract of farm land, they automatically were given a lot in the townsite of Fowlerton.

A cotton gin, large rail depot, hotel, two banks, department stores and schools were all built. There was even a seafood restaurant featuring fresh oysters and shrimp that were brought in on ice from the coast by rail car.  Fowlerton Texas featured several paved streets, sidewalks, fire hydrants and free flowing artesian water wells, (which unfortunately contained some salt.)  The “Artesian Route” as described on the SaU&G railroad advertisement, referred to the areas numerous flowing wells.

The San Antonio, Uvalde & Gulf Railroad Company, nicknamed the “Sausage” connected the new farming center with faraway markets for produce such as onions, cabbage, spinach and other vegetables that were grown by the farmers. The following flyer is from Fowlerton’s newspaper, the Fowlerton Reporter. You will notice many town names, such as Prince and New California that exist in no form today.

old flyer from SAU&G railroad in South Texas

At the height of Fowlerton’s heyday, somewhere between 2000 to 4000 people called the town and immediate vicinity home. Over the years a series of droughts, combined with the negative effect of watering the farms with saline artesian well water, forced almost all the farmers to leave the country. A few remained and switched to ranching but by the 1960′s the town of Fowlerton Texas was down to about two hundred residents. Now census figures show that only about a hundred hardy souls remain.

What does remain in great number are hundreds of small lots, many of which have dubious ownership. Because of the “buy ten acres, get a town lot” system, many farmers never used or even claimed ownership of their town lots from the very beginning of the subdivision, starting in the 1900′s. Over the years many of these lots were sold for back taxes or claimed under the “quit claim deed” law, that enables one to claim ownership simply by occupying the land and paying taxes. Other owners kept up their taxes, though those parcels have no  road access and have been used for generations by local ranchers as their own. Another issue is that the town was incorporated, with official roads and streets, which still  may be legally opened up and which run right through tracts of land, next to (and even through) existing houses and barns, etc. There is no city government so who get any oil and gas royalties from the land occupied by the dozens of active and abandoned streets?

All of this is an attorney or landman’s nightmare  and when it comes to tracking down the owners of these lots it won’t be easy especially since the records are many, are kept in two different county courthouses (LaSalle County and McMullen County). For this reason the township of Fowlerton, as well as a similar Wintergarden community, Los Angeles, will likely be the last acreage to be leased by major oil companies.

Below is a recent photo of Fowlerton as it appears today.  Of all the buildings that were built in the once prosperous town only a handful of non-residences remain standing. The old Red Store, (rear left), which was once owned by Mr. O.W. Herman and sons, now serves as the post office.  (Ironically and sadly,  as the biggest economic boom in Fowlerton’s history arrives, the government is considering closing down the post office there.) The Baptist church is located two blocks off of highway 97 and the old Catholic church, now boarded up, sits surround by cactus and mesquite just off of Texas street.

Fowlerton Texas U.S. Post Office

One thing is for certain, and that is the little community is about to experience the biggest “land rush” since the days of the Fowler Brothers. Most of the interest will be in mineral rights of property outside of the town.  The vast number of owners of the town site lots may make drilling in the Fowlerton town site prohibitive since it may be difficult to get all of the thousands of owners  to lease enough land for wells to be drilled.  Whether this oil boom will lead to any real population growth for Fowlerton remains to be seen.  For those with fond memories of  towns like Fowlerton and Los Angeles Texas, there is hope that these historic towns may be revived from “ghost town” status.

Update: 09/02/2011

Reliable sources have indicated  that EOG Resources has assembled a team at the Cotulla, TX office to begin tracking down the owners of mineral rights in the old Fowlerton Texas townsite. Initially the company, which has leased up most of the land around the 2000 acre townsite, had decided to avoid the area, due to the difficulties involved.  As production figures began to come in from new wells on either side of Fowlerton over the past few weeks, things apparently changed. The fact that EOG Resources already has contact information for many of the townsite lot mineral rights owners, (due to the fact that they have already leased many of the associated 10 acre+ parcels in the old Fowler Brothers development), is a plus.  Still, the process of tracking down all of the remaining owners may take months, but may be worthwhile for EOG in the long run. Fowlerton is apparently is situated at a “sweet spot” in the Eagle Ford shale play, which could potentially contain millions of dollars worth of oil and natural gas.  Currently EOG Resources is in the process of either drilling or planning to drill several new wells in the River Lowe Ranch lease, located about 2.6 miles northeast of  Fowlerton, and  in the Naylor and Jones Unit 43, about 3 miles to the southeast of town. See map below:

Article by Nolan Hart. 

EOG Resources has focused their efforts on the oil window of the Eagle Ford shale. According to a report they recently published for investors they have indicated that the Eagle Ford shale may be one of the most significant oil discoveries in over 40 years.  

Why Is There So Much Oil In Northern Part Of  The Eagle Ford Shale?

The reason is that most of the oil stayed in the source rock (the shale).  In the oil window of the Eagle Ford some oil migrated up into the porous Austin chalk and a few good wells were drilled in the 1980′s.  Little did oil companies know then that there was literally an ocean of oil in the shale beneath the Austin chalk formation.

After all, shale was just a nuisance to be drilled through on the way to real reservoir rock such as sandstone and limestone.  Along a wide band north of the Edwards reef trend there are wide areas which were never known for oil production. It has now been recognized that there are great quantities of oil that has been sealed into the shale by impermeable rock layers above the Eagle Ford. 

In the past oil companies drilled a few wells in this area but quickly abandoned their search because the kind of geology for trapping oil in reservoirs, such as porous limestone or sandstone, simply did not exist and the technology to get oil out of the shale below had not been perfected or even imagined yet. 

 In the late 1980′s, when the Austin chalk oil boom was going on, they had horizontal drilling and hydraulic fracturing technology.  It’s just that nobody had ever considered that the two technologies could be used to recover oil and gas from shale. Finally it dawned on someone to try it in the Barnett shale and that’s where the whole revolution began. 

The map below is from Petrohawk Energy. It shows the oil window at the upper portion of the Eagle Ford shale where pressures and temperature is lower. Condensate is found in wells in the middle and lower part of the play.  All of this has to do with how underground heat and pressured cooked off the various hydrocarbons and forced some to upper formations. At the lower middle edge of the Eagle Ford shale, bordered by the Edwards Reef trend and the Sligo reef trend we see the dry gas window. Here high pressure, high volume natural gas is present and here is where Petrohawk holds the majority of their Hawkville Field property.

EOG Resources and other companies are focusing on the condensate window and the upper oil window while Petrohawk, Pioneer and Conoco are among the companies focusing on the southern gas rich, deeper end of the Eagleford shale near the Sligo reef.

EOG has drilled several test wells across a 125 mile swath of the ol window and confirmed that this will be one very widespread oilfield. One of those wells drilled just east of the old community of Zella in northwestern McMullen county is producing over 400 barrels a day.

It will be interesting to see how far the north end, the “oil window” is pushed. There will be some marginal wells and areas where it will be determined that the expense of drilling and hydraulic fracturing do not warrant completion.

Read more about EOG Resources plans for the oil window of the Eagle Ford shale:  EOG Plans