Network drilling for Shale Gas

John Wilkinson made this Freedom of Information request to Oil and Gas Authority

This request has been closed to new correspondence. Contact us if you think it should be reopened.

The request was partially successful.

Dear Oil and Gas Authority,

Will it be necessary for Fracking operators to drill from vertical shafts a network of lateral galleries at different depths in different directions below the gas window in order to recover the extensive potential volumes of shale gas forecast in various government publications?

If not, can you please indicate the alternative mechanisms which will be adopted to maximise the gas yield?

If so however, can you please confirm that government agencies will veto network drilling for Fracking in areas of the UK which have a significant volume of underground faults, in order to avoid seismic events?

Yours faithfully,

John Wilkinson

OGA FOI requests,

Dear Mr Wilkinson,
 
Thank you for your two follow up emails of 2 February.
 
These communications are not being replied to under the Freedom of
Information Act as they do not specifically request information or
documents actually held by the OGA, they seek clarification or opinion on
technical matters or policy. As such, we are replying to them as normal
business.
 
You asked “Will it be necessary for Fracking operators to drill from
vertical shafts  a network of lateral galleries”. It is likely that shale
gas production will entail horizontal drilling, though ‘galleries’, in the
sense of open mined voids, will not be a feature of shale gas production.
 
You also asked whether “government agencies will veto network drilling for
Fracking in areas of the UK which have a significant volume of underground
faults, in order to avoid seismic events”. I refer you to the guidance for
Hydraulic Fracture Plans (see [1]EWT and HFP guidance (PDF, 257KB, 3
pages), which sets out the systems that will be in place to minimise the
risk of activating any fault by fracking.
 
Also, in your previous email, you asked us to clarify what we meant by not
holding the information in the same form as we had at the Aughton event.
 
At the Aughton event we presented information supplied by UKOGL, but the
OGA does not hold a copy of it at this time. You can download it freely
from the website at [2]www.ukogl.org.uk.
 
I hope this information is of help.
 
Yours sincerely,
 
Strategy Directorate.
 
Oil and Gas Authority is a limited company registered in England and Wales
with registered number 09666504 and VAT registered number 249433979. Our
registered office is at 21 Bloomsbury Street, London, United Kingdom, WC1B
3HF.
 
For information about how we process data and monitor communications
please see our Data Protection Statement and for terms of use please see
our Terms and Conditions, both available on our website.
 
 

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Dear OGA FOI requests,
Thank you for your response dated 9/2/2017 to my FOI Request. One aspect of my Request was though not dealt with other than correcting the terms I used. I hope therefore you can respond if I reword the question.

"In order to harvest shale gas in the quantities estimated by the government to be available in the UK, will it be necessary to drill and frack laterally at a range of horizontal levels in the shale layer because of its low permeability?"

Yours faithfully,

John Wilkinson

OGA FOI requests,

Dear Mr Wilkinson,
 
Thank you for your further follow up email of 10 February 2017, in which
you have re-worded one of your questions for clarity.
 
Again, because your request for information does not contain a specific
request for copies of information held by the OGA, it will be dealt with
as a 'normal course of business' enquiry rather than a formal request for
information under the FOIA or the EIRs. This is in accordance with
guidance given by the Information Commissioner’s Office which advises that
“requests which are not for recorded information, but instead ask
questions, such as "please explain your policy on x" or, "please explain
your decision to do y" are not requests for recorded information and
therefore should be treated as routine correspondence”.
 
The OGA has not estimated the amount of shale gas which might be produced
(harvested), but has commissioned the BGS to estimate the potential
volumes of hydrocarbons in the subsurface; the resource potential.  A
large volume of in-place gas and oil resource has been assessed to be
present.  However, until some wells have been successfully tested, not
enough is known to estimate a recovery factor or to estimate potential
reserves – what might be produced.  It is also not yet known whether
multiple levels could be targeted.   See “Onshore reports” on
[1]https://www.ogauthority.co.uk/exploratio...
 
Shale does have lower permeability than sandstones through which gas and
oil flow more freely, so hydraulic fracturing will need to be applied to
enable gas to flow into the well from shale.
 
I hope that this is helpful.
 
Yours sincerely,
 
Strategy Directorate.
 
Oil and Gas Authority is a limited company registered in England and Wales
with registered number 09666504 and VAT registered number 249433979. Our
registered office is at 21 Bloomsbury Street, London, United Kingdom, WC1B
3HF.
 
For information about how we process data and monitor communications
please see our Data Protection Statement and for terms of use please see
our Terms and Conditions, both available on our website.
 

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