Antelope-4 ST-1 Drilling Report

[petrengr1]

Pet - Thanks a million for your thoughts concerning our time-frame and some of the possibilities that could be going on currently.I guess our huge amount of very porous dolomite can also be a hindurance when it comes to getting a solid cement job.Don't particularly like the smaller pipe and tubing situation,but I guess"it is what it is". Please keep up your outstanding and helpful work .

I share your imagined troubles with porous limestone being encountered substantially earlier than anticipated.  How much cement needed to fill that hole?  Could be a lot.

Pet might comment on whether the smaller casing size now precludes horizontal drilling and whether even while reduced in size A4 will remain as a prolific production weill.

Art- Due to the lack of information provided I am afraid we have more questions than answers.

As I have explained before there is no reason to worry about the cement going into the high porosity dolomite since the cementing is being done above the pay zone.

I do not think there is any plan to drill a horizontal hole at this location but it is just a simple side track at a relatively small angle. This is based on OSH’s comment that the planned TD is 2,375 meters.

We do not know if the 5” liner will just cover perforations in the bottom of the 7” liner, will come up above the top of the 7” liner or come all the way to the surface. I expect that it is the penultimate. A well at this location will have the capability to be prolific producer but at Antelope-4 ST-1 the size of the open hole and tubulars might restrict the flow somewhat. It will still be capable of respectable flow rate.  I don’t think any of the wells drilled to date have been prepared  to be producers but they can be prepared for that purpose. I am thinking they will want the wells to be capable of  producing up to 200 MMCFD each. They will probably need to revise the casing program and plan to use 7” production tubing. I doubt that Antelope-4 ST-1 will be utilized as a producer due to the down hole configuration (shallow side track) ,size of the tubulars and hole size. The well should partially accomplish its purpose i.e. evaluate the quality and extent of the dolomite on the south flank of the field. Based on their last map the well will not be able to find the limits of the field to the south.

Here is a bonus for you. When we talk about prolific wells , remember the high flow rates at Antelope-1 and Antelope-2 and now find that Antelope-5 produces 60 MMCFD with a drawdown of about 2 psi , I believe this has significant implications for the resource volume calculation. Why? Because the wells have such a high deliverability and minimum pressure drawdown that the reservoir can be produced to a much lower abandonment pressure than most other reservoirs.

Have a good day!!