Transcript Changes in the Directional Drilling and Surveying Markets

Changes in the Directional Drilling
And
Surveying Markets
• Introduction
The purpose of this discussion is to update everyone with what is available in the market
and give a general description on why and how this technology can assist you with
your drill programs. It will cover the main items that you may run into, or be asked
about, in the field today.
• Surveying
– Brief History – Starting years ago with Acid tests and standard film
single shots, Canadian Drilling Contractors have been taking survey tests in drill
holes to provide requested information to their clients. Over the past decade
extreme changes have come about with the introduction of numerous new tools
and suppliers.
With these changes have come secondary survey methods, contractors who
work solely in this market and some introduction of “in-house” divisions to handle
these requests.
– Types of instruments
• Magnetic Survey Instruments – Single and Multishot
Photographic Single and Multishots – Record a film record of a compass and
gravity dip indicator at a drill hole depth to be read and recorded by the
client. Useful tools but are being phased out due to easier to use electronic
tools.
Electronic Single and Multishots – These tools use a combination of
accelerometers and magnetometers in conjunction with an electronic timer
and on board memory to record azimuth and dip information. The ease of
use and in some cases multiple functions of these tools makes them
superior to film based units. Due to the on board sensors used it is also
possible to determine and record the magnetic field intensity and dip to
assist in determining if possible interference has been pick up in the reading.
• Non Magnetic Survey Instruments
– Gyros – These instruments use similar accelerometers to record dip
but use a gyro which records deviation in the drill hole free from any
interference caused by possible magnetics.
The 3 main types in use in this market are
» Mechanical Free Gyros
» Rate Gyro Systems
» North Seeking Gyro Systems
– Other Options – Other commonly used tools in this category are
based on curve measurement or light reflection area. As the tools pass
along the drill string measurements are taken and movement is
determined based on visible ring area or strain on instrument
components.
The main tool that fits into this category is the Reflex Maxibore. Recent
introduction of a Devico Deviflex tool generates similar results and past
Lightlog or Boretrack tools work on similar principles.
– Several Companies are currently working on, or are in the testing phase on new
non-magnetic survey instruments. Most are based on gyro principles and within
the next 12 to 18 months. It is believed that some of these may be introduced
that are sufficiently robust and operator friendly that Mining Companies and Drill
Contractors may incorporate these into their operations or services.
– List of Manufactures / Suppliers
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Reflex Instruments *
International Directional Services *
Ranger Survey Systems
Pajari
- Halliburton Sperry Sun *
- Borinfo *
- Icefield Tools
- Flexit
* indicates companies that supply both magnetic and non-magnetic
survey tools.
Note: I.D.S. and Borinfo are mainly service suppliers
Survey Summery
With the speed at which the market is changing and with the introduction of new
easier to use tools, it is believed your clients will start to request more information
about these options.
Most everything has benefits and some disadvantages so knowing your project and
clients needs is key to selecting the proper tool, Supplier or Contractor. This will
mean less down time for you and proper data for them.
Federal requirements are starting to change and going forward it is believed due
diligence in regards to survey data and hole location will take a larger role. Better
to know your options than to be behind when the questions arrive.
Directional Drilling
A self described definition of directional drilling is any drill hole that the
contractor attempts to change or alter the azimuth or inclination of the
drill hole through downhole assembly selections, wedging or directional
drilling tools.
Under this definition almost all drilling contractors have been required at
some point to directional drill or control their drill holes. When these
times arise, being prepared, planning, proper method selection, having
the right know how, and incorporating these items will result in a
smoother completion. This also assists in quicker, more cost effective
completion of the total project.
Main Methods for Directional Drilling
Bottom hole assembly selection - with the introduction of stabilized full hole
barrels, longer reaming shells and better bit technology it is now easier to control
a drill hole by setting parameters for crews to follow. This will not steer a hole in a
particular direction but will assist in minimizing or using the formations natural
tendencies. Not a new method but becoming more efficient.
Directional Wedges or Retrievable Wedges - Directional wedges are used
to cut off an existing hole and start a secondary hole. These can be set off bottom
enabling the contractor to set up and correct if a hole is heading off line.
Retrievable wedges are used when a client wants no steel left in the hole. These
are set off bottom and need to be planned ahead of time to avoid allowing the
hole to drift to far off line.
These options are fairly common in the Canadian Drilling Industry and are handled
almost exclusively by the drill contractors.
Positive Displacement Motors - Directional motors got their start in
the oilfield years ago. For the past 15 to 20 years they have been
available in sizes that are more common for the mining industry. This
equipment uses a large amount of fluid to pass through a power section
and transfer rotational power to the bit. In using fluid to rotate the bit the
motor can then be manufactured with a bend and create side hole force
to deviate drill holes.
Over the last 5 years or so we have seen major changes to the power
sections to provide more HP and bearing changes to avoid unnecessary
wear. These have also benefited for better bit technologies and survey
tools. This has allowed for easier use and more accurate control of
doglegs and target requirements. Motor have been used throughout
Canada and have controlled deflections past 2000m in depth.
Because of these changes some drill contractors are electing to run this
equipment on certain projects without the need for an outside contractor.
Devico Directional Corebarrels -
This tool has been around since 1999 in
a NQ wireline option. For the first few years it had some difficulties but has come
a long ways and is now proving to be a reliable option for directional drilling. It
works by utilizing two outer barrel and an inner tube to retrieve the core.
When the water is pumped past the tool it expands a packer and disengages a
locking pin which holds the outer barrel in place against the hole wall and allows
the inner barrel to provide the rotation to the bit. The system is complicated and
requires frequent repairs and cleaning as well as strict attention to pressures and
variables.
The system is available in standard form B and H sizes but requires the tool to be
pulled from the hole every drill run. These tools may work similar to a retrievable
wedge but for longer deflections would be labour intensive.
This system can be run by contractors but requires personnel commitment and
proper service planning to avoid breakdowns and delays.
List of Manufactures / Suppliers
– International Directional Services
– Major Drilling Group
– Devico Directional Tools
The above companies supply separate directional contracts and
personnel to drilling companies or mining companies that require these
services.
Other Canadian drilling contractors have also used these tools to great
success by using experienced supervisors and foreman to oversee
these projects.
Additional Specialty Tools
Core orientation tools,
Directional Software and Hole Planning,
Basic Geophysical Services
As with most things specialty service companies are changing and
more than every new tools and technologies will continue to be
developed and offered to contractors to better their services.