Interesting post from the Californian's website...
Geol Guy made a good stab at explaining the situation.
But let's face it, it is not reassuring to see water being
produced at this early stage. If it is being coned in from
the zone which at first produced the strong gas flare, it
could come from mobile water in the pore spaces
although not usually in large enough volumes to
extinguish a flare. But in larger volumes, more than
likely, such water flows come from a zone of high
water saturation deeper down that is coning up into the
17 feet of pay that have been penetrated.
If the zone of high water saturation is far enough down
and gas producing zone is thick enough, the well could
hold some promise under prudent production practices.
If the entire zone is fractured or if there are vertical
fractures throughout the zone, you are f----d. Just ask
the Amoco boys about a deep hot gas play (12,000
-15,000 ft at 350 deg F.)in northern Canada called
Beaver River and Pointed Mountain that came on
stream in the early 1970's. The normal flow tests
showed that they had a huge reservoir but just to make
sure they flow tested these wells at 50+ MMCFD for a
full month I believe with pressure bombs in the hole
with no sign of depletion or water. If my recollection is
correct, the Beaver River field went on production at
around 250 MMCFD for about a year before the ocean
came in leaving one well to wimper along at about 5
MMCFD. The Pointed Mountain field produced for a
longer period but had similar problems.
Analysis showed that they had a fractured reservoir
open to an active water drive west to the mountains.
Porosity was divided in to matrix-type and
fracture-type with most of the gas (volume and
rate)being produced from the frature system. Once the
pressures in the fracture systems started to drop, the
water started to move essentially trapping the gas in
the matrix part of the porosity resulting in early
depletion and watering out of the wells. I believe the
geological and engineering guys that were involved in
that wrote a paper on that project and made a
presentation to SPE in the middle 1970's.
In the case of East Lost Hills, the play is large in areal
extent. Now that the well is down and has almost
reached it projected TD, full evaluation is pretty much
required. The source of the water has to be determined
through systematic testing and analysis and $$$. No
amount of speculation is going to answer definitively
anybody's concerns at this stage. But we have gone
from "Yes, we have a well, a big well" to
"Maybe...maybe." So hedge your bets.
Food for consideration.
JL |
