7/17/2019 CTD
1/9
CANADIAN COILED TUBING HORIZONTAL DRILLING:
TECHNOLOGY AND APPLICATIONS
R. HATALA* M. OLANSON P. DAVIS**
this article begins on the next page FF
JCPT95-06-01 Canadian Coiled Tubing Horizontal Drilling:
Technology and Applications R. HATALA* Zeeland Horizontal Lt(i.
M.OLANSON Audryx Petroleum Ltd. P. DAVIS** Zeeland Horizontal Ltcl.
now with Lionheart Energy Corp. now with Technical Research
Services Abstract Canada has played a prominent role in the
development of horizontal drilling technology. To date, over 1,400
"grassroots" and "re-entry" wells have been drilled. Although other
countries have experienced greater numbers of wells, the number of
dif- ferent types, varieties, and formations tested with this
Canada is unparalleled. Due in part to the exponential growth of
horizontal well applications since the mid-1980's, coiled tubing
(CT) technology in Canada has been adapted and evolved for more
traditional uses such as horizontal well stimu- lation, evaluation,
workovers, and clean-outs. The principal non- traditional aspect of
CT is its use in drilling operations. This paper will deal with the
current state and recent advances in CT horizontal drilling in
Canada. A brief historical perspecti ve will be presented that
highlights Canada's presence as a pioneer in CT dr
documents its evolution from vertical re-entries dating back to
1974, grassroots vertical wells in 1976, to the industry's current
efforts at vertical and horizon- tal CTD. The principal Canadian
service companies are reviewed in terms of present capabilities in
CTD applications and the per- ceived driving forces that are
stimulating the development of this emerging technology. The key
factors such as diameter and fatigue life of the coil, length
limitations, bottom hole assem- blies, surveying methods and the
economic and market factors affecting CTD relative to more
drilling techniques are reviewed. Finally, the future
technological, market and economic devel- opments necessary for the
successful implementation of CTD for grassroots vertical and
horizontal well re-entry projects are suggested. Introduction The
exponential growth in the number of horizontal well appli- cations
in Canada and internationally over the past eight years has led to
a relatively rapid development ot'both personnel and equip- inent
to enhance the horizontal drilling method of exploiting exist- ing
oil field gas pools. In Canada, there are an estim
producing wells: 40,000 gas wells and 30,0()O oil wells.
Recently, the National Energy Board (NEB) presented a study of
horizontal oil wells and their impact on future crude oil supply in
Canada. 'They estimated that there is a potential market of over
horizontal wells that can be economically drilled within 1.800 oil
pools at a market 22 price of, $)() US/Bbl. O f these 12.000 wells,
5,000 were believed to be grassroots in nature (1,100 have been
drilled to date) while 7.000 were horizontal re-entries through
existing cased wells (300 have heen drilled to date). Of
thre-entries, the competition for services will be between slim
hole (less than ()r equal to 6-1/4 in. hole size) conventional
drilling systems using drilling or modified service rigs and coiled
tubing drilling (CTD) technology. Add to this potential market
vertical deepen- ing horizontal lengthenings and grassroots wells
coupled with increasing interest in horizontal exploitatio n of gas
pools, and the developniedt of'CTD appears to be poised for
exponential growth iti Canada over the next live years. Some of the
questions that will be addressed durin- the course of this
were the significant factors that allowed ihe enelution of CTD
in Canada? Can it become competitive with coiiveiitional drilling
technology What is the key market niche tlizit Aill ailt)w its
development? And finally, What are the future developments that are
required to allow CTD to compete effec- tivelv in vertical and
horizontal drilling applications in Canada? An Overview of Coiled
Tubing Drilling Technology The use of CT deployed mills and
underreamers, powered by positive displacement motors (PDM) or air
motors to clean out cement of hardened till and scale in ca
estab- lished as a CT completion technology. CT re-entry
operatio ns LIS to deepen wellbores in order to access additional
productive formation a bare-foot completion was the first
application of open-hole drilling with coiled tubing in Canada. Sub
sequently, slim hole deepenings have proven effective in coring,
testing and evaluating deeper formations or drilling into sensitive
formations. the CTD industry in Canada has progressed from vertical
deepings and vertical grassroots wells to horizontal lengthen-
ings, re-entries and finishings and will be discussed in more d
applications and market assessment segments (see the Glossal for
definitions)- The principal advantage of CTD over conventional
drilling operations is the CT industry's knowledge and experience
in live- well workovers allowing CTD's natural evolutionary step to
be underbalanced drilling Other advantages are: simplicity, in
increasing the automation of the drilling process and reducing the
manpower required: mobility, with the potential of reducing the
response time and mobilization costs with compact on-site units:
economy with faster drilling times due to the eliminatioJournal of
Canadian Petroleu m Technology
