spring the U.S. Department of Energy actively solicited input from
the petroleum industry on microhole technology -- and got it, when
an April workshop brought in 63 representatives from industry, government
and laboratories to identify the primary potential applications
for microhole technology in an effort to focus new research.
comments at the meeting:
producers preferred using microhole technology for shallow development
producers leaned toward exploration tails.
companies preferred drilling holes for data.
also identified five critical technologies necessary for microholes
to be worthwhile. These are:
most technologies, industry officials indicated that microhole technology
must evolve from current applications rather than seek to revolutionize
the industry -- and without government assistance the technology
would be slow to develop.
participants indicated that with DOE financially supporting its
development, majors and independents will employ microhole technology,
which will spur service companies to invest in technology development.
maintained that a targeted cost savings of 40 to 50 percent (compared
with existing technology) would be necessary to push the use of
participants highlighted four primary drilling applications:
Shallow development wells (maximum depth of 6,000 feet).
said this was the number one application for microhole technology.
to 20,000 shallow development wells will be drilled in the United
States this year, with only a handful using coiled tubing. Canada,
on the other hand, drills 10,000 to 20,000 shallow wells each year
and hundreds employ coiled tubing.
growth in shallow drilling in the United States in recent years
has come from coalbed methane plays in Wyoming, Kansas, Oklahoma
and New Mexico -- but almost every onshore U.S. basin has mature
shallow oil and gas reservoirs that could benefit from this technology,
according to the report.
oil and gas producers were particularly interested in using microhole
drilling to reduce the initial capital cost of a shallow development
independent commented, "The cost of drilling a conventional 5,000
foot well is $13 to $17 per foot in West Texas. Completed cost is
$250,000 to $350,000 -- $150,000 is a really attractive price at
which we'd drill wells all day long.
would do that, great, but it must be reliable and repeatable."
attendees indicated coiled tubing operations save space, simplify
logistics and can improve well performance. However, people expressed
concern about the hydraulics of drilling very small diameter holes.
must the technology do to be applicable for shallow development
microhole technology must drill a very small diameter hole from
surface to targeted depth quickly and cheaply with a minimum footprint
in a manner that is reliable and repeatable. Producers are very
comfortable with the traditional rotary drilling process and have
made significant strides in lowering costs and drilling time, so
for a coiled tubing-based microhole technology to be attractive
the cost differential must be substantial -- about 50 percent.
technical hurdles for this application beyond the hole itself are
reliable tools designed for microholes.
Reservoir data monitoring holes.
could be used to acquire seismic data, vertical seismic profiling,
reservoir pressure and temperature data, rock samples and fluid
that type of information today companies must use an existing well,
drill a standard-sized well or use a coring/slim hole rig to drill
a small diameter hole.
technology can potentially provide an alternative for gathering
data at lower costs, with a smaller footprint, with no lost production
and better data through optimum well placement -- but, again, the
need for this application is limited to larger companies. Small
operators rarely operate a unitized field.
and service company officials indicated that few data sampling wells
are drilled in the United States each year, primarily due to the
high cost of such operations. If the cost of constructing these
holes can be substantially reduced, it is likely the number of data
sampling holes will rise sharply.
Shallow re-entry wells.
to 100 re-entry wells are drilling daily in the United States, according
to the report -- producers will spend at least $7.5 billion in 2003
re-entering existing wellbores, and microhole technology could significantly
reduce the cost of the operation.
tubing drilling is used every day to exit cased wellbores, but none
are the size of microholes. The bottomhole assemblies, logging tools
and the entire drilling operation have been set up to drill conventionally
workshop participants indicated that all systems -- motors, measurement
while drilling, logging, whipstocks, bits -- must be developed before
reliable microhole drilling can be performed in the United States.
and production equipment for new hole sizes should be studied to
determine which additional equipment and services need to be developed.
Deep exploration tails.
of drilling a very small diameter hole out the bottom of a conventionally
drilled exploration well in order to evaluate an additional 2,000
feet of rock prior to plugging and abandoning a test hole.
obvious use of this technique would be in very high cost deepwater
wells, where the total measured depth of the hole is around 20,000
often run out of hole with the last casing run and can't investigate
further. Companies would welcome an inexpensive option to drill
a tiny investigative hole out the bottom of the last casing string
to take samples, measure pressure and temperature and evaluate zones
just below the targeted formation of interest.
concerns among workshop participants centered on the high temperature
and pressure regimes in deepwater wells. (One company official said,
"I can't imagine a one-inch tool that can withstand the pressure
of a 15,000-foot hole. I can't believe it's feasible to develop
systems and hydraulics for deep applications and high pressures.")
concern was how to transmit power to the drill bit.