opinion on jka from a different forum, page-6

GreatSwami knowledgeable article.. (see PAPERBIZ89 intro post 9619125) was interesting, then he added the followup on Investor Village

"As I (and BBO) pointed out - the flows they are getting (have gotten) to date before getting the tubing planted are from badly damaged fracture porosity. I thought I had made the case that should they get the tubing out of the hole and clean it up again and if they can "unplug" the worst of the formation damage either through natural flowing, swabbing, acid squeezes (or even mini fracs) - there is the potential for significantly greater flow rates from the formation.

All I wished to clear up was the ambiguity of the news release with respect to the considerable arm waving going on over transient and short lived flow rates. There are many factors that affect the measurement of flows at surface and one of the biggest is any "slugging" where measurement of instantaneous flow rates can yield erroneous expectations. (I've seen this lots of times from the spurious effects of wellbore storage as you open the valve on a shut in gas well through all the events while drilling underbalanced oil wells and from flows encountered while drilling with kicks on conventional overbalanced wells. You can get all kinds of phenomenal short term transient flow rates due to rapidly changing wellbore hydrodynamics - but it is the amount of fluid (water oil and/or gas) that has flowed cumulatively over the fixed period of the complete flow period that is germane in any estimation of possible flow rate ranges.

I have seen gas wells produce transient flow rates of over 4-5 mmcfpd on valve open due to wellbore storage effects but which can only flow at a stable 0.1-0.2 mmcfpd when all the excitement is over... Similarly I have been on underbalanced wells where during a mechanically induced transient drawdown there were flows recorded of over 2000-3000 bopd from wells that when placed on stable production yield only 250-400 bopd under normal production drawdown conditions. (Quite respectable still for the type of reservoir being drilled!)

The important takeaway is that the Jacka well is flowing oil from a fractured Abiod reservoir even after having been very badly insulted during drilling operations. It is quite likely that in a completely undamaged state of production the flow rates could easily be from 5-10 times greater. It is uncertain given the history (revealed from some of the comments on the above mentioned forum) that the formation damage can be completely bypassed or healed?

So where their final production rates end up depends on a whole lot of things going right for them - but the well in an "as is" and badly compromised state appears capable of about 300-350 bopd and if it can be improved the ultimate (but unlikely to be achieved) best case scenario might be between 1500-3500 bopd.

But before any of these blue sky scenarios is achieved - they have to get the tubing "unstuck" - and the statistics for doing so in a horizontal well with the information given to date makes that scenario seem problematic. While technically feasible - again they have a whole lot of things that can still go really badly pear shaped and only one way of getting free and clear...

I wish them the very best of luck in this regard - but I have a skeptical view of the probabilities.

Returning to the DXE situation - our case is rather different. We have a vertical well not a horizontal one - big difference in what can be achieved and to what impact mechanically. We have probably done considerable damage to the fracture plumbing during drilling and with all the noted difficulties encountered during attempts to get the hole stable enough to get casing run to bottom and cemented in place. The amount of damage occurring while drilling a vertical well through this zone is likely much less than that occurring while drilling it horizontally. However we have added cement - I do not think anything was cemented over the horizontal portions of the Jacka well?

Most importantly we are not stuck in the hole - and in the unlikely event of finding the tubing buried in drilled solids while attempting to complete any perforated zone - there are many more tools available in the tool kit to get unstuck from such a situation in a vertical hole than there are in a horizontal one. Also since we are completing from the bottom up testing several identified fracture zones - any troubles encountered on the lowest zones do not have any (significant) impact on those above. With a horizontal well when you are stuck inside the liner at some unspecified position - if you have to shoot off above the problem (before the problem?) everything beyond that point is lost. When moving up in a vertical well - you only ever need to be able to produce from the very top of the reservoir as the fracture plumbing (aided by an active water drive) will deliver all the oil to you over time anyway!

What we can see though from the Jacka well is simply this - even a very badly damaged set of fracture zones on a horizontal well seem capable of delivering flow rates from 300-400 bopd - and undamaged this can be projected to be considerably greater. There is no reason the fracture zones (several) on the DXE well cannot do equally as well...GS"

Thanks GS you should post more often on HC.