Drilling Progress at Antelope-6

[jft310]

Don't you love Monday Morning Quarterbacks????Or give them a break they are the best managed Super Major in the world these days . No it will never be perfect .

[petrengr1]

This appears to be the right string for the information I posted on another string. So here is the latest on the Antelope-6 drilling progress as of Feb. 23, 2016:

From OSH:

"On Antelope 6 we've just taken our fourth core in the reservoir and we're doing an intermediate logging run. We'll test on the way down and then we'll drill out through the reservoir and do a longer term test and also an injectivity test as well.

I think once we've got all that data over the next sort of two, three, four weeks I think we're going to have a very good, a good feel for the resource base and all of that data is and will be provided to our certifiers."

[petrengr1]

This appears to be the right string for the information I posted on another string. So here is the latest on the Antelope-6 drilling progress as of Feb. 23, 2016:

From OSH:

On Antelope 6 we've just taken our fourth core in the reservoir and we're doing an intermediate logging run. We'll test on the way down and then we'll drill out through the reservoir and do a longer term test and also an injectivity test as well. I think once we've got all that data over the next sort of two, three, four weeks I think we're going to have a very good, a good feel for the resource base and all of that data is and will be provided to our certifiers.

I am moving my comments of Feb. 25th to this thread since that appears to be where it belongs:

Pet - I believe the injectivity test is to keep them from creating the mess that happened with the cement job in the A4 well ...is that the case? Also,if they have taken 4 cores so far in the reservoir,can I assume that we are already into the top 100 ft or so? (of the 450 ft) We'll test on the way down" .....dsts maybe ?  [ I guess I'm just too doggone anxious to find out more about this eastern part of the reservoir !! ] .

Sageo- They have set the casing above the reservoir. After the cement had time to set they would have run cement bond logs, drilled out the bottom of the casing and done a test of the casing shoe by pressuring the well bore to a pressure of about 1 psi/ft of depth. The cement bond logs and leak-off test were apparently OK indicating the cement bond is good. So they drilled into the reservoir some time before pulling the pressure gauges from Antelope-1 and Antelope-5, based on the progress they have already made, i.e taken 4 cores and now doing an intermediate logging run. It is hard to say how far they have drilled into the reservoir but you would think it would be a significant amount if they have enough open hole to justify an intermediate logging run. It is a bit odd that they took four cores and then also wanted to see a log before drilling ahead. I don't think they will be doing any open hole drill stem tests (DST) but they will probably set the packer near the bottom of the casing and test all of the open hole. It could be that they will test as soon as the intermediate logging run is completed. It will be interesting to see if they drill all the way to the planned TD which, as you know is several hundred feet below the gas/water contact. If they drill all the way down before doing the longer term test they will have to plug off the water zone below the gas/water contact before testing. The other possibility of course would be to drill down to the gas/water contact depth and do the longer term test which I believe will also be done with the packer set in the casing,  testing the entire open hole section. They will eventually need to drill below the gas/water contact at least far enough to run a log across the interval where we think the gas/water contact is in order to confirm its location (again), if possible. The injectivity test on a producing well is new to me. Such tests are usually done on water injection wells or water disposal wells. However such a test could probably be done in conjunction with a Schlumberger logging tool in the hole to see where the fluid is going. The test would be done using fresh water and could be used to locate permeable zones and perhaps to get an estimate of the permeability. They may do the injection at a constant rate and then do a pressure fall off test. Similar to the pressure buildup test after a production test. I would have thought it would be better to run a Schlumberger production log while producing the well to see where the gas is coming from. In either case they will probably be able to locate the permeable zones where the gas is coming from. Most of the gas will probably be coming from a very high porosity zone or a fractured zone.

The last information we had from our best source of information (OilSearch) was as of Feb. 23. 2016: On Antelope 6 we've just taken our fourth core in the reservoir and we're doing an intermediate logging run. We'll test on the way down and then we'll drill out through the reservoir and do a longer term test and also an injectivity test as well. I think once we've got all that data over the next sort of two, three, four weeks I think we're going to have a very good, a good feel for the resource base and all of that data is and will be provided to our certifiers."

We will get another update on March 3rd when OSH publishes their Drilling Report effective the end of February. So we get to see what they did for about 6 days after the last report of Feb. 23rd.

[sageo]

Pet - As aways,thanks very much for the March 1 post above. (great education you are providing us ! ) I thought we should be at least 100 ft into the reservoir and it now looks like about 203 ft . ( close to 40 ft of dolomite as of today's report) .....hope at least one of those cores was in a fractured limestone area with good porosity. Looking forward to when you post your next "educating lesson".

[petrengr1]

Pet - As aways,thanks very much for the March 1 post above. (great education you are providing us ! ) I thought we should be at least 100 ft into the reservoir and it now looks like about 203 ft . ( close to 40 ft of dolomite as of today's report) .....hope at least one of those cores was in a fractured limestone area with good porosity. Looking forward to when you post your next "educating lesson".

Antelope-5-  There is a bit of a discrepancy between the data reported today as compared to the data reported on the first test http://tinyurl.com/q2lzmbq page 17. On the first test they say they produced 60 MMCFD through two 48/64” chokes. Now on this latest test they say they produced 57 MMCFD through a (one?) 48/64” choke. One or the other is incorrect.

The good news is, of course, that the new data has confirmed the connectivity between Antelope-5 and Antelope-1.

They are still evaluating the pressure buildup data to “quantify nearby reservoir properties”. I do not know what this means unless they are trying to prove the distance to the nearest fault. I assume that would be the western fault. As I have stated before I do not think they can learn much from a near instantaneous 2 psi pressure buildup but I wish them luck. I do not know what more they can learn about the permeability since we already know it is unbelievably high as proven by the 2 psi drawdown for 60 MMCFD.

We await the additional data of the reservoir pressure loss for the amount of gas produced which is what they would use to try to estimate the gas in place in the reservoir.

Antelope-6

I will try to tell you what we know and what we don’t know.  IOC has been using sub sea depths in all of their previous reports but today they switched to drill depth, just to keep us guessing.

They have previously reported that we topped the reservoir at -2,076 meters sub sea or about 76 meters lower than they had it mapped. The top of the pay would be at 2,262 meters drill depth. Today’s report says they cut four cores across the interval from 2,268 to 2,330 meters drill depth. They do not indicate if all of the interval was cored or part of it was drilled without coring but the depth of the hole is currently 2,330 meters drill depth (-2,144 meters sub sea). They say a 9 5/8” liner was set at the top of the zone (2,262 meters drill depth). So we have open hole from 2,262 meters drill depth to 2,330 meters drill depth or 68 meters (223 feet) . They tell us “Preliminary interpretation shows approximately 12 meters of dolomite is present in the drilled section.”  What we do not know is where the 12 meters of dolomite is in the 68 meters of drilled hole. Is it at the top of the zone, the middle of the zone or the bottom of the zone? It makes a big difference. The best possible scenario would be that they have high porosity limestone from 2,262 meters to 2,318 meters and then 12 meters of dolomite at the bottom of the hole. That would mean they were still drilling in dolomite when they decided to log and test. At Antelope-3 we had high porosity limestone above the dolomite section and the dolomite section was in about four different segments with limestone between the sections of dolomite. See the logs at http://tinyurl.com/l2j4c2w  page 17. So no matter where the dolomite section is in the drilled interval it is still possible that we will have more dolomite when they drill the rest of the hole. The bottom of the hole is presently at 2,330 meters drill depth or -2,144 meters sub sea. We know the gas/water contact is somewhere between -2,214 and -2,228 meters sub sea. IOC has been using -2,214 but Hession has said data from Antelope-4 and Antelope-5 indicate the gas/water contact may be lower than they had been using. The -2,228 meters sub sea number was from the GLJ report and I think it is the most likely depth for the gas/water contact. So using -2,228 meters sub sea we have another 84 meters (276 feet) to drill before reaching the gas/water contact. I think some of that formation yet to be drilled could be dolomite.

Now let’s look at the test data. On the surface it does not look too great, 13 MMCFD on a 40/64” choke. What we do not know here is whether or not they have a bottom hole choke in the DST tools, what the tubing (drill pipe) size is and whether or not we have formation damage caused by drilling fluids. If the dolomite is as good as previous wells 12 meters (39 feet)  of dolomite should produce more than 13 MMCFD on a 40/64” choke. They did not give us the flowing tubing pressure at the surface but I would guess it to be about 1,200 psi. So we have a lot of pressure loss for some reason...bottom hole choke, small tubulars and/or formation damage. As you know the reservoir pressure is about 3,500 psi. If we have formation damage they will determine that by analyzing  the bottom hole pressure build up data after they pull the DST tools and gauge. Formation damage in a high porosity limestone or dolomite can be corrected with hydrochloric acid.

I am looking forward to hearing about the final log and flow test information, if they do further testing.

[wapitidropiti]

Pet - As aways,thanks very much for the March 1 post above. (great education you are providing us ! ) I thought we should be at least 100 ft into the reservoir and it now looks like about 203 ft . ( close to 40 ft of dolomite as of today's report) .....hope at least one of those cores was in a fractured limestone area with good porosity. Looking forward to when you post your next "educating lesson".

Antelope-5-  There is a bit of a discrepancy between the data reported today as compared to the data reported on the first test http://tinyurl.com/q2lzmbq page 17. On the first test they say they produced 60 MMCFD through two 48/64” chokes. Now on this latest test they say they produced 57 MMCFD through a (one?) 48/64” choke. One or the other is incorrect.

The good news is, of course, that the new data has confirmed the connectivity between Antelope-5 and Antelope-1.

They are still evaluating the pressure buildup data to “quantify nearby reservoir properties”. I do not know what this means unless they are trying to prove the distance to the nearest fault. I assume that would be the western fault. As I have stated before I do not think they can learn much from a near instantaneous 2 psi pressure buildup but I wish them luck. I do not know what more they can learn about the permeability since we already know it is unbelievably high as proven by the 2 psi drawdown for 60 MMCFD.

We await the additional data of the reservoir pressure loss for the amount of gas produced which is what they would use to try to estimate the gas in place in the reservoir.

Antelope-6

I will try to tell you what we know and what we don’t know.  IOC has been using sub sea depths in all of their previous reports but today they switched to drill depth, just to keep us guessing.

They have previously reported that we topped the reservoir at -2,076 meters sub sea or about 76 meters lower than they had it mapped. The top of the pay would be at 2,262 meters drill depth. Today’s report says they cut four cores across the interval from 2,268 to 2,330 meters drill depth. They do not indicate if all of the interval was cored or part of it was drilled without coring but the depth of the hole is currently 2,330 meters drill depth (-2,144 meters sub sea). They say a 9 5/8” liner was set at the top of the zone (2,262 meters drill depth). So we have open hole from 2,262 meters drill depth to 2,330 meters drill depth or 68 meters (223 feet) . They tell us “Preliminary interpretation shows approximately 12 meters of dolomite is present in the drilled section.”  What we do not know is where the 12 meters of dolomite is in the 68 meters of drilled hole. Is it at the top of the zone, the middle of the zone or the bottom of the zone? It makes a big difference. The best possible scenario would be that they have high porosity limestone from 2,262 meters to 2,250 meters and then 12 meters of dolomite at the bottom of the hole. That would mean they were still drilling in dolomite when they decided to log and test. At Antelope-3 we had high porosity limestone above the dolomite section and the dolomite section was in about four different segments with limestone between the sections of dolomite. See the logs at http://tinyurl.com/l2j4c2w  page 17. So no matter where the dolomite section is in the drilled interval it is still possible that we will have more dolomite when they drill the rest of the hole. The bottom of the hole is presently at 2,230 meters drill depth or -2,144 meters sub sea. We know the gas/water contact is somewhere between -2,214 and -2,228 meters sub sea. IOC has been using -2,214 but Hession has said data from Antelope-4 and Antelope-5 indicate the gas/water contact may be lower than they had been using. The -2,228 meters sub sea number was from the GLJ report and I think it is the most likely depth for the gas/water contact. So using -2,228 meters sub sea we have another 84 meters (276 feet) to drill before reaching the gas/water contact. I think some of that formation yet to be drilled could be dolomite.

Now let’s look at the test data. On the surface it does not look too great, 13 MMCFD on a 40/64” choke. What we do not know here is whether or not they have a bottom hole choke in the DST tools, what the tubing (drill pipe) size is and whether or not we have formation damage caused by drilling fluids. If the dolomite is as good as previous wells 12 meters (39 feet)  of dolomite should produce more that 13 MMCFD on a 40/64” choke. They did not give us the flowing tubing pressure at the surface but I would guess it to be about 1,200 psi. So we have a lot of pressure loss for some reason...bottom hole choke, small tubulars and/or formation damage. As you know the reservoir pressure is about 3,500 psi. If we have formation damage they will determine that by analyzing  the bottom hole pressure build up data after they pull the DST tools and gauge. Formation damage in a high porosity limestone or dolomite can be corrected with hydrochloric acid.

I am looking forward to hearing about the final log and flow test information, if they do further testing.

Pet, There is no mention of condensates, Is this important?

[petrengr1]

Pet - As aways,thanks very much for the March 1 post above. (great education you are providing us ! ) I thought we should be at least 100 ft into the reservoir and it now looks like about 203 ft . ( close to 40 ft of dolomite as of today's report) .....hope at least one of those cores was in a fractured limestone area with good porosity. Looking forward to when you post your next "educating lesson".

Antelope-5-  There is a bit of a discrepancy between the data reported today as compared to the data reported on the first test http://tinyurl.com/q2lzmbq page 17. On the first test they say they produced 60 MMCFD through two 48/64” chokes. Now on this latest test they say they produced 57 MMCFD through a (one?) 48/64” choke. One or the other is incorrect.

The good news is, of course, that the new data has confirmed the connectivity between Antelope-5 and Antelope-1.

They are still evaluating the pressure buildup data to “quantify nearby reservoir properties”. I do not know what this means unless they are trying to prove the distance to the nearest fault. I assume that would be the western fault. As I have stated before I do not think they can learn much from a near instantaneous 2 psi pressure buildup but I wish them luck. I do not know what more they can learn about the permeability since we already know it is unbelievably high as proven by the 2 psi drawdown for 60 MMCFD.

We await the additional data of the reservoir pressure loss for the amount of gas produced which is what they would use to try to estimate the gas in place in the reservoir.

Antelope-6

I will try to tell you what we know and what we don’t know.  IOC has been using sub sea depths in all of their previous reports but today they switched to drill depth, just to keep us guessing.

They have previously reported that we topped the reservoir at -2,076 meters sub sea or about 76 meters lower than they had it mapped. The top of the pay would be at 2,262 meters drill depth. Today’s report says they cut four cores across the interval from 2,268 to 2,330 meters drill depth. They do not indicate if all of the interval was cored or part of it was drilled without coring but the depth of the hole is currently 2,330 meters drill depth (-2,144 meters sub sea). They say a 9 5/8” liner was set at the top of the zone (2,262 meters drill depth). So we have open hole from 2,262 meters drill depth to 2,330 meters drill depth or 68 meters (223 feet) . They tell us “Preliminary interpretation shows approximately 12 meters of dolomite is present in the drilled section.”  What we do not know is where the 12 meters of dolomite is in the 68 meters of drilled hole. Is it at the top of the zone, the middle of the zone or the bottom of the zone? It makes a big difference. The best possible scenario would be that they have high porosity limestone from 2,262 meters to 2,250 meters and then 12 meters of dolomite at the bottom of the hole. That would mean they were still drilling in dolomite when they decided to log and test. At Antelope-3 we had high porosity limestone above the dolomite section and the dolomite section was in about four different segments with limestone between the sections of dolomite. See the logs at http://tinyurl.com/l2j4c2w  page 17. So no matter where the dolomite section is in the drilled interval it is still possible that we will have more dolomite when they drill the rest of the hole. The bottom of the hole is presently at 2,230 meters drill depth or -2,144 meters sub sea. We know the gas/water contact is somewhere between -2,214 and -2,228 meters sub sea. IOC has been using -2,214 but Hession has said data from Antelope-4 and Antelope-5 indicate the gas/water contact may be lower than they had been using. The -2,228 meters sub sea number was from the GLJ report and I think it is the most likely depth for the gas/water contact. So using -2,228 meters sub sea we have another 84 meters (276 feet) to drill before reaching the gas/water contact. I think some of that formation yet to be drilled could be dolomite.

Now let’s look at the test data. On the surface it does not look too great, 13 MMCFD on a 40/64” choke. What we do not know here is whether or not they have a bottom hole choke in the DST tools, what the tubing (drill pipe) size is and whether or not we have formation damage caused by drilling fluids. If the dolomite is as good as previous wells 12 meters (39 feet)  of dolomite should produce more that 13 MMCFD on a 40/64” choke. They did not give us the flowing tubing pressure at the surface but I would guess it to be about 1,200 psi. So we have a lot of pressure loss for some reason...bottom hole choke, small tubulars and/or formation damage. As you know the reservoir pressure is about 3,500 psi. If we have formation damage they will determine that by analyzing  the bottom hole pressure build up data after they pull the DST tools and gauge. Formation damage in a high porosity limestone or dolomite can be corrected with hydrochloric acid.

I am looking forward to hearing about the final log and flow test information, if they do further testing.

Pet, There is no mention of condensates, Is this important?

Wapit- Yes it would be interesting to know how much condensate was recovered per MMCF. We have always been told that the condensate content would increase with depth but we have never had a well that had good porosity near the gas/water contact. Most of the gas tested in the other wells came from high porosity zones many hundreds of feet above the gas/water contact. At Antelope-4 and Antelope-6 we have (or had) a chance to see if the condensate content is higher with depth. The other wells had about 15 Bbl/MMCF and we can rest assured that we have at least that much at Antelope-6 which is much closer to the gas/water contact. Unfortunately we did not get a test at Antelope-4. Condensate and/or oil burns with a bit more orange flame than just natural gas. Do I see a little darker color to the flame in picture they showed today?

[bdahl385]

Pet - I was happy to see the dolomite show up in A6 but then was disappointed also in the flow test at 13 MMCFD on a 40/64” choke. I was initially thinking formation damage or flow constrained by other mechanical means (tubing / down hole choke / etc). Is it possible that the reservoir at A6 just has primary porosity only with little/no fracturing? I would think the further you move away from the western fault line, the less likely for the formation to be impacted by the folding and tearing of the matrix. Without a substantial fracture network, the permeability would be much lower than the prolific number seen in A5. Oilfield 101 refresher: porosity is the value of the "void" in the matrix where the fluid resides whereas permeability is the ability for that fluid to move through the matrix with ease and ultimately into the tubing to surface.

The recent poor drilling results on well 2 and 3 for OSH in Iraq's Taza prospect showed that their reservoir fracturing varied substantially from well to well. This made the field appraisal much lower than hoped after their initial discovery well that hit the sweet spot of the fracture network.

But keeping it real, A6 was never expected to be that great a well - it was to provide control in an unknown boundary of the field. On balance today's report is better than I hoped for.

[sageo]

Pet - Thanks for your fine analysis of the report . I too noticed they had switched to drill depth.....maybe you are right with "just to keep us guessing".

         True,they did not give us the exact location of the dolomite . You very astutely pointed out (page 17 of the 2012 pdf  showing the Antelope logs), that the dolomite is not always in the very top of the reservoir. I would like to believe,as you say is possible, that we may drill thru more dolomite as we go down the hole.

         As I dream tonight, I hope to see a much darker orange in your "imaginary flame" .." border="0" class="smilie" src="http://shareholdersunite.com/mybb/images/smilies/biggrin.gif" />...

[petrengr1]

Pet - I was happy to see the dolomite show up in A6 but then was disappointed also in the flow test at 13 MMCFD on a 40/64” choke. I was initially thinking formation damage or flow constrained by other mechanical means (tubing / down hole choke / etc). Is it possible that the reservoir at A6 just has primary porosity only with little/no fracturing? I would think the further you move away from the western fault line, the less likely for the formation to be impacted by the folding and tearing of the matrix. Without a substantial fracture network, the permeability would be much lower than the prolific number seen in A5. Oilfield 101 refresher: porosity is the value of the "void" in the matrix where the fluid resides whereas permeability is the ability for that fluid to move through the matrix with ease and ultimately into the tubing to surface. The recent poor drilling results on well 2 and 3 for OSH in Iraq's Taza prospect showed that their reservoir fracturing varied substantially from well to well. This made the field appraisal much lower than hoped after their initial discovery well that hit the sweet spot of the fracture network. But keeping it real, A6 was never expected to be that great a well - it was to provide control in an unknown boundary of the field. On balance today's report is better than I hoped for.

Bdahl- Yes, I also believe there will be more fractures as the wells get closer to the fault, however we should keep in mind that what we have been calling the western fault is a very low angle thrust fault. As you know the location of the fault shown on their maps is where the fault crosses the top of the  zone. So vertically even Antelope-6 is not too far from the fault. I do believe the extremely high flow rates we have seen at the other Antelope wells is due to fracture permeability. Also with the lower flow rate at Antelope-6 it appears that the interval being tested does not have a fracture zone or the flow rate would have been higher. They have probably drilled the well so far with mud in the hole since without a fracture zone they probably would not have lost circulation. Thus we could have some skin damage or damage to the matrix porosity/permeability. I do not remember how far the fracture zone has been below the top of the pay zone but it well could be lower than we have drilled so far. Even if we do not have a fracture zone in the well if we have 152 meters (500 feet) of limestone and dolomite with decent porsity we should be able to clean the well up with acid and get the flow rate up to 100 MMCFD or so. If we have good porosity all the way to the gas/water contact we should see some improvement in the gas/condensate ratio compared to the up dip wells. As you know the top 500 feet of the reservoir in the up dip wells is the best of the pay zone.