Dick,
    I think we need to make a  clear distinction between coal mining 
subsidence and drilling for oil.  My  home town in Illinois has also suffered from 
mine subsidence as a result of room  and pillar evacuation from 1901 - 
1925.  The problem was the 6' seam of  Herrin #6 coal was only 250' or less 
below the surface.  A 10' excavation  at a 250' depth gives only a 25 to 1 
ratio.  After about 50 years, there  was surface subsidence.  Most homes were not 
affected, but some were, and I  understand some govt. agency compensated 
the home owners for damages  sustained.
   You should not have anything to worry about as  the result of 
directional drilling from a single location.  The drill bit -  about 12" in diameter, 
goes down to maybe 10,000' and then drills horizontally  in the target 
formation.  A horizontal hole of approx. 12" diameter 10,000'  deep and 
subsequent formation fracturing will not result in any surface  subsidence.  This is 
a 10,000 to 1 ratio compared to the coal mine.   Remember also that the hole 
is cased; additionally, the bore hole and fracture  zones will be filled 
with fluid, giving additional resistance to  overburden pressure.  There have 
been thousands of horizontal wells drilled  and fracked without incident to 
my knowledge. 
    As to earthquakes, the drilling guy you  talked to is correct.  Oil or 
gas well drilling to relative  shallow depths as opposed to the considerably 
deeper foci quake  depths should not cause any tremors.  However a deep 
disposal well  used to dispose of fluids from wells might conceivably be 
drilled deep enough to  intersect a relatively shallow fault plane.  This in turn 
could  theoretically lubricate the fault surface and result in fault 
movement  precipitating some minor tremors.
    In summary, I would not be concerned about  oil or gas well drilling 
causing property subsidence many years later.  
    Al
 
 
 
In a message dated 12/8/2010 2:11:27 P.M. Central Standard Time,  
dickthomas01@............. writes:

On  12/7/2010 1:05 PM, _AHrubetz@........ (mailto:AHrubetz@........  wrote: 
 
If the land is severed between surface and mineral  ownership, the owner of 
the mineral rights may lease the land for  drilling.  The lessee then has 
the right to drill on the property, but  must negotiate and settle with the 
surface owner for whatever damages are  inflicted on the property.  In most 
areas where there has been much  drilling, this amount is usually 
predetermined.  Leases  normally contain a provision that the lessee cannot drill 
within a  designated distance from an abode.  Lessee must also maintain roads,  
etc.
Al
OK Al,& others  that makes sense but.....They  ARE drilling up to six 
directions from a single vertical hole. There could  be  environmental issues 
down the line long after the drilled area is  drained. Now this isn't quite the 
same but coal mining occurred under this  city and in the area over 140 
years ago. We  see effects even today  from these mine passages collapsing. Who 
is liable in something that occurs  200 years later? The drilling operator 
I talked to said that these  earthquakes in the Guy, AR (and southern 
llLinois) area could not have a  significant effect on earthquake frequency. Most 
geologists in AR, IL and  Memphis area seem to agree. They also point to the 
fact that drilled wells  don't go down that deep .... maybe 15,000 ft at 
the most...(most New Madrid  activity is below 10 miles and the Guy stuff 
about half as deep). The long  range effect worries me. Even the farfetched idea 
 of the disturbing of  shallow bedrock could allow vertical movement of 
salt water  along  fault surfaces created in berock below the fracking 
activity.  


A quick addendum .... at least two sources  (Memphis and Arkansas 
geologists) believe that  the Guy area site is a  new (undiscovered) fault that could 
cause a 7+ mag quake..... and just to  bring you back to earth... another 
geologist susgestts hot spring activity may  be to blame and predicts the 
earthquakes will not get much larger.


.










Dick,
    I think we need to&nbs=
p;make a=20
clear distinction between coal mining subsidence and drilling for oil.&nbs=
p; My=20
home town in Illinois has also suffered from mine subsidence as a result=
 of room=20
and pillar evacuation from 1901 - 1925.  The problem was the 6' seam=
 of=20
Herrin #6 coal was only 250' or less below the surface.  A 10' excava=
tion=20
at a 250' depth gives only a 25 to 1 ratio.  After about 50 years, th=
ere=20
was surface subsidence.  Most homes were not affected, but some were,=
 and I=20
understand some govt. agency compensated the home owners for damages=20
sustained.
   You should not have anything to worry about=
 as=20
the result of directional drilling from a single location.  The drill=
 bit -=20
about 12" in diameter, goes down to maybe 10,000' and then drills horizont=
ally=20
in the target formation.  A horizontal hole of approx. 12" diameter=
 10,000'=20
deep and subsequent formation fracturing will not result in any surface=20
subsidence.  This is a 10,000 to 1 ratio compared to the coal mine.&n=
bsp;=20
Remember also that the hole is cased; additionally, the bore hole and frac=
ture=20
zones will be filled with fluid, giving additional resistance&nb=
sp;to=20
overburden pressure.  There have been thousands of horizontal wells=
 drilled=20
and fracked without incident to my knowledge. 
    As to earthquakes, the drilling guy=
 you=20
talked to is correct.  Oil or gas well drilling to relative=
=20
shallow depths as opposed to the considerably deeper foci quake=20
depths should not cause any tremors.  However a deep disposal we=
ll=20
used to dispose of fluids from wells might conceivably be drilled deep eno=
ugh to=20
intersect a relatively shallow fault plane.  This in turn could=20
theoretically lubricate the fault surface and result in fault movement=20
precipitating some minor tremors.
    In summary, I would not be concerned=
 about=20
oil or gas well drilling causing property subsidence many years later.&nbs=
p;=20

    Al
 
 

In a message dated 12/8/2010 2:11:27 P.M. Central Standard Time,=20
dickthomas01@............. writes:
On=20
  12/7/2010 1:05 PM, AHrubetz@.......=
 wrote:=20
  

    
    
If the land is severed between surface and mineral=20
    ownership, the owner of the mineral rights may lease the land for=
=20
    drilling.  The lessee then has the right to drill on the property=
, but=20
    must negotiate and settle with the surface owner for whatever damages=
 are=20
    inflicted on the property.  In most areas where there has been mu=
ch=20
    drilling, this amount is usually predetermined.  Leases=20
    normally contain a provision that the lessee cannot drill within=
 a=20
    designated distance from an abode.  Lessee must also maintain roa=
ds,=20
    etc.
    
Al
    
OK Al,& others  that makes sense but...=
...They=20
    ARE drilling up to six directions from a single vertical hole. There=
 could=20
    be  environmental issues down the line long after the drilled are=
a is=20
    drained. Now this isn't quite the same but coal mining occurred under=
 this=20
    city and in the area over 140 years ago. We  see effects even tod=
ay=20
    from these mine passages collapsing. Who is liable in something that=
 occurs=20
    200 years later? The drilling operator I talked to said that these=20
    earthquakes in the Guy, AR (and southern llLinois) area could not have=
 a=20
    significant effect on earthquake frequency. Most geologists in AR, IL=
 and=20
    Memphis area seem to agree. They also point to the fact that drilled=
 wells=20
    don't go down that deep .... maybe 15,000 ft at the most...(most New=
 Madrid=20
    activity is below 10 miles and the Guy stuff about half as deep). The=
 long=20
    range effect worries me. Even the farfetched idea  of the disturb=
ing of=20
    shallow bedrock could allow vertical movement of salt water  alon=
g=20
    fault surfaces created in berock below the fracking activity.=20
    
A quick addendum .... at least two sourc=
es=20
  (Memphis and Arkansas geologists) believe that  the Guy area site=
 is a=20
  new (undiscovered) fault that could cause a 7+ mag quake..... and just=
 to=20
  bring you back to earth... another geologist susgestts hot spring activi=
ty may=20
  be to blame and predicts the earthquakes will not get much larger.

  

    

    
.
<=
/DIV>