From:
MacDonald May [macdonald-may@ns.sympatico.ca]
Sent:
Wednesday, June 04, 2014 9:25 PM
To:
Stephen McNeil
Cc:
Allan MacMaster; Randy Delorey; HFReview
Subject:
Wheeler report Energy Well Integrity
Dear Premier McNeil,
I am writing you regarding the latest “discussion papers “ from the
Wheeler Panel .We are
now a month after the closure of submissions from the public , and yet none
of the information
provided by the public to the panel is included in any of their reports .As I
volunteer , I have
made a submission, and responded to the “primer” and first two discussion
papers . As of yet
there has been no announcement as to how the responses will be incorporated
in the final
report .Dr. Wheelers introduction to the latest document appears to limit
input to matters of
clarity , not correcting misinformation in the draft , or incorporating
additional information into
the final report . Dr. Wheeler’s disinterest in public input was highlighted
in today’s Chronicle
Herald regarding criticism from Duncan Keppie . It appears that after
assembling a panel with
representation from gas industry insiders that gas industry sales brochures
are regarded as
credible evidence , but public input is dismissed out of hand .
It was clear from the manner in which Dr. Wheeler structured the
review and selected his
panel, that the focus of the review was to be myopic and reductionist , as
opposed to holistic
and broad . The science of reductionism is the process of hiding “ death by a
thousand cuts “ ,
each cut is presented in isolation of the others , and so far the panel has
reports have restricted
a review of costs and risks to less than a single page . What I do find
surprising is how
amazingly bad all documents have been, as Mr. Keppie said “garbage”
Yesterday Dr. Wheeler dumped two documents allowing 18 days for
response . While Dr.
Wheeler and his panel are funded by the province, I am not .I have put
hundreds of hours into
my submissions, and reviews of the panel documents , and it all appears to be
a complete
waste of time, as Dr. Wheelers experts will dismiss all my concerns and
evidence in pursuit of
what gives every appearance of a forgone conclusion .
One of the hallmarks of the reports prepared by Wheeler’s panel is
that claims are
presented as facts , with no supporting reference . I quote the
unsubstantiated claims of the
pro shale development panel without comment . Dr. Wheelers reports continue
to be based on
false assumptions, wishful thinking and blinkered ignorance .Below are
unreferenced
statements from Wheelers latest report Energy Well Integrity .In a few cases
I have added a
“Note” , but in most cases not . I don’t disagree with many of the all
statements , but claims
should be supported by evidence, and when conducting a review to assist
government in its
decision making , there information should be referenced and supported by
evidence, not “our
expert knows better than your expert”
“Technological advances are helping to reduce the incidence of leaking wells
and are providing
means for better quality control and leak detection capabilities.”
“the frequency of substantial leaks is low, and the leakage rates are low as
well”
“When leakage is identified, methods exist to rectify the problem. Although
rigorous statistics
remain elusive, it seems that the number of problems encountered in Alberta
and British
Columbia, both relatively mature regulatory environments, is not large.”
“Because possible future unconventional resource development in Nova Scotia
would take place
using modern technology with multiple wellbores installed at each drilling
site, it is a relatively
straightforward task to establish good monitoring and regulatory practices to
ensure that the
site is geologically understood, that wells are properly installed, and that
well abandonment is
done according to best practice guidelines”
“Moderate tectonic stresses and strong rock mean that wellbore quality will
be excellent,
leading to high quality primary cementing operations, and therefore fewer
cases of leaking
wells”
“Well construction practices have also evolved over many decades, as greater
experience has
been gained in different geological conditions, and as new materials and
techniques have been
developed.”
“Since the technique was first introduced in the late 1940’s, more than a
million wells have
been hydraulically fractured worldwide,” NOTE this is a familiar theme in the
papers produced
by Wheeler’s panel , basing safety of unconventional extraction on history of
conventional
operations . The fact that the use of fractures in conventional oil and gas
have not created the
problems that are ubiquitous with unconventional sources is ignored , yet
despite this the report
frequently claims that there have been improvements made in well design and
construction, a
statement Dr. Anthony Ingraffea PhD Rock Fracture Mechanics has ridiculed in
numerous
presentations .
“In onshore Nova Scotia, large volumes of gas at depth and pressures far
above hydrostatic
pressure (10-11 MPa/km) do not exist.”
“standard well designs and safety measures are sufficient to address the
small risk of a
blowout.”
“The first element in creating good wellbore integrity is to make sure each
casing joint is
properly connected to the previous one so that no fluid leakage can take
place through the
connection.” NOTE As Dr. Ingraffea has pointed out “ It is impossible to
build a well that does
not leak”
“With modern cementing practices and quality control, having to immediately
repair a new
well is a rarity.”
“Also, because the production casing is not exposed to mechanical wear,
wellbore integrity is
seldom an issue after the well is properly completed. ”
“Nevertheless, as discussed later, behind-the-casing gas migration continues
to be an issue is a
small percentage of energy wells.” this is footnoted to a previous footnote
which reads ,”9 For a
broad yet detailed discussion of various potential environmental impacts of
shale gas
development in a Canadian context, refer to the following publication:
Council of Canadian
Academies, 2014. Environmental Impacts of Shale Gas Extraction in Canada.
Ottawa (ON): The
Expert Panel on Harnessing Science and Technology to Understand the
Environmental Impacts
of Shale Gas Extraction, Council of Canadian Academies. Commissioned by the
Council of
Canadian Academies for Canada Environment, May 01, 2014. The author served on
this Expert
Panel, and the sections in the Report on well integrity were in large part
formed by the author.”
“The tendency in the industry is to increase the number of centralizers and
scratchers to assure
a better seal for the region between the casing and the rock mass”
“Once the plug hits the shoe, it opens, and the cement slurry flows out of
the shoe and up and
around the casing. Once the appropriate volume of cement is mixed, a second
wiper plug is
placed in the casing to displace all of the cement into the exterior annulus
while wiping the
inside of the casing clean.”
“In this way, future issues relating to well integrity and risks of
interaction with shallow aquifers
will be minimized”
“All these factors, plus the fact that the pressure in the productive horizon
is being lowered
because of continued depletion, means that maintaining well integrity would
be relatively
straightforward. Any problems will most likely be associated with seepage of
gas, not oil or
saline water, because gas is buoyant”
“If loss of casing integrity is observed at any time during production, the
operator must fix the
problem”
“Pathway 1 remains speculative, and compared to other pathways, can
reasonably be left to
effective monitoring and regulatory controls in the context of possible
onshore Nova Scotia oil
and gas development.”
“By contrast, in Nova Scotia, there are only a few abandoned legacy wells
that penetrate deep
into the shale gas strata, and the locations of these wells are well-known,
so the risks of fluid
migration into these wellbores during hydraulic fracturing or other
production activities are
likely minimal.” Note , in the MacIsaac Point area there are numerous
abandoned wells and
their locations are not known.
“Pathway 5 would be of limited concern in Nova Scotia providing that good
quality assurance of
the primary cementing operation is maintained.”
“It is a standard regulatory requirement that the corporation report gas
migration events”
“Once the source is located, perf-and-squeeze operations can be used to shut
the pathway
above the source and greatly reduce the chances of further gas seepage.”
“Although an undesirable event from a greenhouse gas and aesthetic
perspective, the impact of
methane entering potable water sources is not a serious health issue in
comparison to many
other chemical contaminants.26” Note , the claim is footnoted , yet the
relevance of
comparison to “other chemical contaminants” appears irrelevant. Methane is an
explosive gas,
and it’s presence in domestic wells and homes are likely to have impacts
aside from toxicity ,
for instance EPA warnings to people in Pennsylvania to shower and do laundry
only in well
ventilated areas .
“Gas entering shallow groundwater wells may be a nuisance, including
exceptionally an
explosion hazard, but other than making groundwater unpalatable in some
cases, no severe
health impacts appear to have been demonstrated at this time”
“Once the commercial life of a shale gas well is over, often fifteen or more
years, it must be
abandoned according to stipulated practices laid down by the regulatory body”
Note there is no
evidence of any shale gas operations lasting 15 years. the average life of
shale development,
according to economist Deborah Rogers is 6.5 years
“If there is any detectable surface casing vent gas flow, which occurs in
perhaps 10-15% of
wellbores30” , footnote 30 reads “30 Surface casing vent flow data are
registered with the
regulatory agency; therefore, there are excellent statistics available in
this area, in contrast to
gas migration behind casing, where there are few data, insufficient to make
strong quantitative
conclusions.”
“evidence of seepage or loss of pressure integrity between the intermediate
string and the
production string, remediation must be implemented to reduce such flows to
negligible values
before the well is sealed.”
“Cement bond logs, temperature logs, and noise logs may be used to identify
the source of the
gas migration to guide the location of the perforating action, and the well
will have to be
monitored for SCVF before abandonment. Exceptionally, several perf-andsqueeze operations
may be required to reduce seepage rates to mandated levels”
“Probably 70% of these wells have been plugged and abandoned, and although
there are many
instances of gas migration, which must be fixed when noted, there do not seem
to be major
environmental problems arising from the existence of these abandoned wells at
this time.”
“This is not an easy statement to verify because methane seepage has not been
considered by
toxicologists as an issue worthy of their attention, and this is supported by
the lack of
publications in this area. Certainly, there are many areas in the world
(Pennsylvania, central
Alberta) where natural seepage of methane is endemic,”
“In any case, most jurisdictions have “orphan well” funds, provided by a levy
on production, that
are used to fix wells for which an owner cannot be found; otherwise, the
responsibility is that
the owner fix the leaking abandoned well to the standards set by the
regulatory agency.”
“Perf-and-squeeze operations are less likely to be needed in Nova Scotia, for
reasons discussed
before and because general oilfield practice continues to improve. If they
are, there is a
concern that in very stiff dense rocks, the high pressures needed to force
the cement into the
cement-rock system will tend to wedge open natural fractures that could serve
as future
pathways behind the casing.”
“Better sealing agents that can flow into small cracks and which tend to wet
the surfaces of the
cracks would be more effective than cement to seal wellbores, but such
materials (low viscosity
resins for example) have not been widely adopted. As in many other cases,
there is insufficient
publicly available data on the efficacy of practices such as cement
squeezing, and there is also
a reluctance to adopt somewhat more demanding and expensive techniques for
sealing
wells.”Note, an interesting reference to industry’s endemic disinterest in
wells , once they are
no longer producing.
“Better sealing agents that can flow into small cracks and which tend to wet
the surfaces of the
cracks would be more effective than cement to seal wellbores, but such
materials (low viscosity
resins for example) have not been widely adopted. As in many other cases,
there is insufficient
publicly available data on the efficacy of practices such as cement
squeezing, and there is also
a reluctance to adopt somewhat more demanding and expensive techniques for
sealing wells.”
“Summery and Conclusions ,
Unconventional oil and gas development using modern well cementing and
completion
techniques leads to generally good wellbore performance, but there will never
be a 100%
success level in sealing all wellbores against all possibilities of future
leakage. Continued
technological advances are helping to reduce the incidence of gas migration
around active and
abandoned wells through improvements in cementing methods (for example more
centralizers,
better denser cement formulations etc.), new materials for correcting leakage
problems, better
methods for detecting poor-quality cement behind the steel casing in the
hole, even better
methods of detecting slow methane seepage around old abandoned wellbores.
Despite all these
advances, human error will always occur; in the case of oil and gas
wellbores, the risks
associated with inadequate well integrity are not great, as shown by years of
experience with
hundreds of thousands of wells in the western provinces. Nevertheless,
vigilance and explicit
quality assurance practices are necessary to keep incidents of human error
low, and to rectify
problems that may have arisen because of such an error.
The most important wellbore integrity problem, at least in North America and
perhaps
internationally, seems to be gas seepage along the outside of casing, and
this may not be a
severe environmental problem because the incidence of leaking wells can
easily be reduced,
the seepage rates are small in general, and the environmental consequences of
seepage of
natural gas into aquifers and into the atmosphere are not catastrophic,
albeit undesirable.
Because any possible unconventional oil and gas development in Nova Scotia
would take place
using modern technology with multiple wellbores installed at each drilling
site, it is a relatively
straightforward task to establish good regulatory practices in advance to
ensure that the site is
geologically understood, that wells are properly installed with good quality
assurance, and that
well abandonment is done according to best practice guidelines. The mature
regulatory
practices of jurisdictions such as Alberta could serve as a guide to the
establishment of a system
in Nova Scotia, with minor modifications as deemed necessary by local
regulators, scientists
and engineers. Operators can be required to be vigilant and that the data be
made public so
that concerns about activities and impacts may be subject to transparent
oversight.
Developments in regulatory practices continue to be made. For example, a
multi-level
groundwater monitoring well at each multi-well drilling site may be required
in the future in
some jurisdictions, and is
currently being debated in the regulatory world. If this is mandated, the
well should be installed
under the supervision of a licensed third-party before the first borehole is
drilled, and the
groundwater well should be sampled and analyzed initially and each two to
three years
thereafter and until ten years after the last well is abandoned. In this way,
a problem with
energy wellbore integrity that impacts groundwater could be identified soon
and corrective
measures taken before a more severe problem develops over a larger area.
Because each
unconventional oil and gas multi-well pad would be draining the gas from an
area of several
square kilometers (4-6 km2), the number of sites will remain few and fairly
widely spaced, so
that it is far easier to detect issues and rectify them.
The natural advantages that exist in Nova Scotia shale gas regions would lead
to a much lower
incidence of poor wellbore integrity compared to historical practices in
other jurisdictions if
development should ever take place. A few of these are listed here:
? Moderate tectonic stresses and strong rock mean that wellbore instability
during drilling will
be largely absent; high quality wellbores lead to higher quality primary
cementing operations,
and therefore fewer cases of leaking wells.
? Except in the coalbed areas, there appear to be few gas sands at shallow
depth that could
lead to problems with intermediate-depth gas migration behind the casing.
? Shale gas in Nova Scotia is likely to be sweet gas (little to no H2S),
making all operations
easier and casing life longer.
According to analysis by Hayes and Ritcey32, any significant development of
Nova Scotia’s
unconventional oil and gas would not take place for several years, perhaps
much longer. This
gives Nova Scotia time to establish appropriate monitoring and regulatory
systems if the
possibility of such development emerges, and to benefit from more technical
advances in
cementation, measurements, and general scientific knowledge about well
integrity.” Note this
constitutes the entire section . Dr. Hayes and Mr. Ritcey are members of
the “expert panel”
Their opinion may be of interest, but it is no more than opinion.
“Note that the production casing is protected against any issues that might
arise from repeated
high pressure flexing of the cemented casing.”
The above is not exhaustive or complete , simply illustrative .
Thank You for your attention
Geoffrey May
Margaree Harbour