Gravity Gradiometry

[vidon]

To all of those posted above: when I look at the new photos I see the yellow reefal rock surrounds the green lagoon rock, like a donut. All of the drilling to date has been west of the lagoon. I see a whole lot of yellow reef rock to the east of the lagoon that has not been drilled nor mentioned as contributing to EA gross gas estimates. It appears we have only been interested in 1/2 the yellow donut. I am a fat old man that likes to eat the whole donut. Can anybody help me understand why the east half is not being discussed, let alone drilled. Looking forward to your comments, Vidon

Vidon, check out the line showing the gas/water contact. The area to the east of the lagoon, if it is a lagoon, is thought to be below the gas/water contact.

thanks much Thy, makes sense.

[sageo]

Gravity gradiometry is proving to be a game changer for evaluating our prospects in PNG.  It indicates the seismic targets, and used in conjunction with 2-d seismic results, it's a substitute for 3-d seismic, filling in the areas between the lines.

And it, taken in conjunction with seismic and and calibrated by drilled wells, even aids a more precise delineation of Antelope. Enlarge and study slide 22 of the annual meeting presentation.  Where does the slide suggest the prime meat of Antelope lies?

For Antelope I like the more detailed map shown on http://tinyurl.com/palye9e slide 13.

 Pet - Good am. Have you (or any of our other board "kin-folk" ) heard any further up-dates concerning our activities at Ant 4 . Maybe someone has a little bit of new info. Just passin' a bit of time !  Best to you.

[ArtM72]

Pet - Could they run a discovery well to Mule Deer from A4 pad?

[jft310]

Mule Deer is thrust under part of Antelope . Wonder how close they are one to the other?

[petrengr1]

Pet - Could they run a discovery well to Mule Deer from A4 pad?

Art- Mule Deer has apparently morphed from what they used to think. If you look at the GLJ report  
http://tinyurl.com/lrjknkq (maps 4 & 5) you will see that what they formerly called Mule Deer was west of Elk and Antelope and the highest part was even higher than Elk and Antelope. Where the block actually contacts the Elk and Antelope blocks the Mule Deer block appears to be 500 - 600 meters lower than the Elk and Antelope blocks.

The above map does not look anything like the seismic cross section shown on the June 9, 2015 presentation http://tinyurl.com/q2lzmbq chart 23. This cross section shows all of Mule Deer to be deeper than Antelope with part of Mule Deer being below Antelope. I do not know how this seismic line was made or which part of the three structures the seismic line crosses. So on a North/South basis I can not tell which part of the Antelope structure Mule Deer lies below. I can not tell if it is below Antelope-4.

As I mentioned elsewhere it may be difficult to drill through the Antelope structure and into the Mule Deer structure. If we drill through the gas bearing part of the Antelope zone it will be  over pressured at the top and we will still have to fight the lost circulation zones if we use the required heavy mud. If we drill below the Antelope gas/water contact the  reservoir pressure is very near a normal gradient so heavy mud would not be required and we might not need heavy mud. Such a well will probably require a revised casing program so that we can set casing both above the Antelope limestone and again above the Mule Deer limestone. The Mule Deer, being deeper, will be a higher pressure zone than Antelope so the lost circulation zones in the Antelope limestone will have to be  cased off before drilling into the Mule Deer limestone. If the Mule Deer zone contains gas it would be able to flow up the hole and into any lower pressure lost circulation (high permeability) zone in the Antelope limestone. This would be what is sometimes referred to as an under ground blow out and it is a risk that we can not afford to take. So the casing program must be designed to protect us against that eventuality.

[sageo]

Pet - Many thanks for your great post concerning Ant 4 and Mule Deer possibilities....need to cogitate about that some more . It seems that we have a Tiger (or several Tigers) by the tail in  this Eastern Papuan Basin . It appears to me that at this time, we know a lot about Ant 4, but until we get the well finished. there is still some mystery involved . If we have hydrocarbons sitting deeper under Antelope with greater pressures, it's kinda like "Houston,we have a problem" . I'm very glad your engineering skills will help us to one day get all of the "good stuff" into the proper pipelines . Have a pleasant evening .