Download A Review of Slimhole Drilling PDF

TitleA Review of Slimhole Drilling
TagsDrilling Rig Oil Well Casing (Borehole) Geotechnical Engineering
File Size5.7 MB
Total Pages87
Table of Contents
                            ABS TRACT
		Slimhole Technology for Exploration in Remote  ea
		Slimhole Technology for Low-Cost Development Wells
		Sbhole Technology for Reentering Existing Wells
		Slimhole Technology for Horizontal Wells
		Slimhole Technology for Developing Multilateral Wells
		3.1 Cost Savings
		Reduction in Disposal Cost
		Minimizin g Environmental Impact and Nuisance
		Retrofit Slimhole Drilling System
		Modified Mining Drilling System
		Drilling Bits (TSD and PDC Bits)
		5.5 Hydraulic Thrusters
		Early Kick Detection
		5.7 Advanced Slimhole Tools
			Slimhole Logging Tools
			Slimhole Testing Tools
			Slimhole Perforating and Cased Hole Logging Tools
			Directional Drilling Steering Tools
		Slimhole Early Kick Detection
		Slimhole Drilling With Coiled Tubing
		Top drive Drilling Systems
Effects of hole size on overall drilling efficiency
Slimhole reduces both well and site costs
BP slimhole completion on Plungar Field
Nyangou-1 well schematic
Schematic of the section milling operation
Schematic of window mdhg
Slim Drill used a conventional workover rig to perform a 4 1/2-in reen try
Cost saving for different types of reentries
Austin Chalk Trend Map of South Texas
Typical Oryx reentry wellbore configuration
Typical newly drilled wellbore configuration in Austin Chalk
Schematic of dual-opposing horizontal we
Schematic of dual-stacked horizontal we
Schematic of dual-opposing-stacked horizontal we
Schematic of Y-shaped horizontal well
Schematic of the lateral tie-back system
Multilateral drilling activities increase in South Texas
Cost comparison of different types of horizontal wells
the DP DIP and D2P producing zones to reverse decline of the field
Moving cost factor
Daily rig cost factor (including drilling string)
Rig-up time factor
Casing-tubing cost factor
Cost per feet factor
Cost/meter (after Worrall et al
	4 l/&in Depth 4 800 meters
Total well cost vs depth Germany Slimhole vs conventional 2.5% inflation
	The contours represent noise levels in dB
Available weight on bit vs lateral departure typical BHAS with rotation
Available weight on bit vs lateral departure typical BHAS without rotation
Effects of hole size on overall drilling efficiency
	drilling rigs
Schematic of continuous coring mining drill system
Wireline retrievable coring assembly
Eastman Teloco thruster used in slimhole
Amoco expert slimhole well control system
BP's EKD Model
	OGJ July25.1994
SRFT slimhole formation testing tool (after Schlumberger OGJ July
Pivot gun system (after Schlumberger OGJ July
Steerable ddmg system
Instrumented steerable downhole motor
Wellbore diagram 'of example conventional and slimhole wells
	driuers method to a position of maximum using shoe pressure
Example annular pressure loss test
	rotation vs Reynolds Number
Comparison of Lateral Hole Designs
Cost Comparison for 5.000 foot Wells in Canada
Drilling Cost Comparison
Austin Chalk Slimhole (after Hall et al
Austin Chalk Slimhole Reentries (1990 vs1991-92')
comparative Drilling Costs for Newly Drilled Wells
Comparative Drilling Costs-slimhole vs Larger Design
Comparison of Conventional and Slimhole Rigs.45
(Faure et al
PDC Bit Performance in the Gulf of Mexico
Cost Savings
	County New Mexico
Underreamer cost per feet comparisons for Texas
Slimhole Wireline Logging Tool Diameters (Randolph et al
Slimhole annular pressure losses (Bode et al
Document Text Contents
Page 1


OKLAHOMA A BDM Federol Company

Status Report


Tao Zhu and Herbert 8. carroll

September 1994

Work Performed Under Contract No.

prepared for
Rhonda Lh-, Pmgram Manager

Bartlesville Project Office
us. Department of Energy

Page 2


This report was prepared as an ac count of work s ponsored by an
agency of the United States Government. Neither the United States
Government nor any agen cy Thereof, nor any of their employees,
makes any warranty, express or implied, or assumes any legal
liability or responsib ility for the accuracy , completeness, or
usefulness of any information, apparatus, product, or process
disclosed, or represents that its use would not infr inge privately
owned rights. Reference herein to any specific commercial product,
process, or service by trade na me, trademark, manufacturer, or
otherwise does not necessarily cons titute or imply its endorsement,
recommendation, or favoring by the United States Government or any
agency thereof. The views and opinions of authors expressed herein
do not necessarily state or reflect those of the United States
Government or any agency thereof.

Page 43

Transportation and environmental problems associated with the use and disposal of drilling fluids are
also significantly reduced.

300-1 / \ 4 \
0 4 I fin\ 1

-400 -300 -200-100 0 100 200 300 400
Distance, m

(a) Slimhole rig

-400 -300-200 -100 0 100 200 300 4
Distance, m

(b) Conventional rig

Figure 3-9 Noise contour maps of a typical slimhole rig (a) and a conventional rig @). The
horizontal and vertical axes represent distances in meters from center of rig. The
contous represent noise levels in dB.

Another advantage of slimhole technology is emission reduction. Since the equipment needed
for slimhole drilling is smaller than a conventional rig, fuel consumption and gas emissions to the
atmosphere can be proportionately reduced. Table 3-2 shows a comparison of fuel consumption for
slimhole rig, coiled tubing unit and conventional rig.47

Table 3-2 Fuel consumption and Gas Emissions of a CI'D Unit, Slimhole Rig and
Conventional Rig (Fame et al. 1994).

CTD Slimhole Rig Land
unit or Workover Rig Drilling Rig

Diesel m3/month 25 35 160
2,122 3,293 15,055

Gas co 2.5 3.7 16.8
2.1 4.6 21
2.8 3.9 17.8
1.1 1.83 8.4
2.2 4.2 19.4

Emissions Nox

HC reas)


Page 44


Slimhole drilling technology can cut the drilling and completing costs significantly.
However, the cost savings achieved from slimhole drilling can be offset by increased mechanical
failures, reduced lateral hole length and lack of directional control. ' Factors that affect operations and
economics in slimhole drilling are as following.

One of the disadvantages for slimhole drilling is drillstring failures associated with use of
small diameter tubulars. The reduced weight of slimhole drillpipe makes the drillstring mechanically
weaker than its conventional equivalent. For example, when changing drillpipe from 5 %-inch to 3 K-
inch, the torque transmission capability will be reduced by a factor of five. Therefore, the strength of
the smaller diameter drillstring is always a concern, espeaally in the milling operation where high
torque is encountered. To k t a j n power, bit speed has to be raised. In addition, higher rotating speeds
are required to maintain cutter linear sp High bit speed may create
reliability problems.

as reducing bit diamet

Tool joint failure is another problem for slimhole drilling. Because of small and thin tubulars
and joints, they are-inherently weaker and have a tendency to bellying and twist-offs, particularly in
deeper holes. The industry now has designed and tested high torque tool joints and premium pipe to
reduce the incidence of failures.

Kick detection is a difficult issue for slimhole drilling b e a unit of reservoir gas entering
a slimhole annulus will occupy a much greater height than in conventional wells. This can result in
maximum allowable pressure in the casing being approached faster than in a conventional well. For
example, the containment of a kick within 10 to 15 bbl on a conventional well'is considered reasonable.
However, this volume of gas in a slimhole would blow out. The capability of early kick detection is
therefore [email protected] Therefore, it is necessary to defect a gain &thin one barrel for slimhole drilling
to be sure of retaining safe control. Unlike conventional-hole drillstring geometric, the frictional
pressure losses in slimholes are very sensitive to rotation speed of the pipe. In addition, the pressure
measured at the standpipe will be affected by other operational changes such as pump rate, pipe
movement and coring. The cause of an increase in return-mud flow rate is more difficult to identify when
the effects of more than one of the above operatiois occur simultaneously.~ All of these factors make
kick detection more difficult. Also, the most likely time for the occurrence of a kick is during a
connection, when the pumps are switched off and pressure exerted against the formation is reduced to
mud hydrostatic.

Another disa for slimhole drilling is decre in penetration rates, especially for
cone bits. As shown in Figure 1-1, penetration rates reach to optimum as hole size is between 11

s to 6 % inches. When using roller cone bit, penetration rates tend to decrease as hole size
decreasing below l25 inches, due to reduced cutting structure and smaller bearing of slimhole roller
cone bits. Decreasing in penetration rate can offset the cost savings achieved from slimhole drilling.
The low rates of penetration were the main inherent operating problems for slimhole drilling in the

Depth is a key limiting factor when considering slimhole well design, espeaally in
exploration. By the available technology, slimhole drilling can reach to about 15,000 feet. Conoco



Page 86
















Slimhole Special Edition 1994. Evaluation and Workover Services to Fit Smaller Wellbores. Oil
b Gas ]ournaZ, Oilfield Bulletin, Schlumberger Technology News, July, 25, pp. 1,4.

DeLuaa, F.V. 1989. Benefits, s, and Applicability dr Steerable System Drilling. Paper
SPE/IADC 18656, presented at the SPE/IADC Drilling Conference, New Orleans, LA, February
28-March 3.

Williamson, J.S. and Lubinski, A. 1986. Predicting Bottomhole Assembly for Horizontal Drilling.
Paper SPE/IADC 14764, presented at the SPE/IADC Drilling Conference, Dallas, TX, February 9-

Peach, S.R. and Kloss, P.J.C. 1994. A New Generation of Instrumented Steerable Motors Improves
Geosteering in North Sea Horizontal Wells. Paper SPE/IADC 27482, presented at the SPE/IADC
Drilling Conference, Dallas, TX, February 15-18.

Samworth, J.R. 1992. Quantitative Open-Hole Logging with Very Diameter Wireline Tools,
presented at the SPWLA Symposium, Oklahoma City, June.

Genrich, D. S., Prusiecki, C. J., and Dunlop, F. L. 1993. Fully Fktrievable, Slimhole Gamma Ray
MWD System Minimizes the Risk of Horizontal Drilling. Paper SPE/IADC 25691, prepared for
presentation at the 1993 SPE/IADC Drilling Conference held in Amsterdam, February 23-25.

Soulier, L. and Lemaitre, M. 1993. E.M. MWD Data Transmission Status and Perspectives. Paper
SPE.IADC 25686, presented at the SPE/IADC Drilling Conference, Amsterdam, February 23-25.

Prince, P.K. and Cowell, E. 1993. Slimhole Well Kill-A Modified Conventional Technique,
SPEIIADC Drilling Conference, Amsterdam, February 22-25.

Hytten, N. and Parigot, P. 1991. Analysis while drilling applied to kick detection, paper
presented at IADC European Well Control Forum, Stavanger, Norway, June 12th-13th.

Hage, J.I., Surewaard, J.H.G. and Vullinghs, P.J.J. 1992. Application of Research in Kick
Detection and Well Control, Third Annual IADC European Well Control Conference,
Leeuwenhorst, The Netherlands, June 3rd-4th.

Orban, J.J. and Zanker, KJ. 1988. Accurate Flow-Out Measurements for Kick Detection, Acaval
Response to Controlled Gas Influxes, IADC/SPE Drilling Conference, Dallas, Texas, February.

Lejeune, M., Mawet, P. and Delwiche, R. 1992. A New Way to Design Slimhole Drilling
Hydraulics. Paper presented at Hydrosoft '92, Valencia, Spain, July.

Delwiche, R., Lejeune, M.W.D., Mawet, P.F. and Vighetto, R. 1992. Slimhole Drilling
Hydraulics, SPE 24596, presented at the 67th Annual SPE Technology Conference, Washington,
DC, October 4-7.

Kardysh, V.G. and Molchanov, V.L. 1974. Losses of Circulating Fluid Pressure with High Drill
String Rotating Speeds, Razvedka Olchrana Ne&, No. 7, pp. 23-27.

Ferrell, €3. Fitch, E.C. and Boggs, J.H. 1958. Drill Pipe Rotation Reduces Pressure Drop. World
Oil, April, pp. 158-164.


Page 87

109. Banks, S. M, Hogg, T. W., and Thorogood, J. L. 1992. Increasing Extended-Reach Capabilities
Through Wellbore Profile Optimization. Paper SPE 23850 presented at IADC/SPE Drilling
Conference, New Orleans, LA, February 18-21.

110. Loland, J.H. 1994. From Sea To Shore. Exploration and Production Technolosy International, pp.


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