American Oil and Gas Reporter - September 2016 - 61

SpecialReport: Horizontal & Innovative Drilling
A secondary issue in horizontal wells
is cement channeling and poor cement/casing bonding in both the horizontal portion
of the intermediate casing string in the
curve section and in the lateral liner/casing.
Cement integrity is improved by the
casing vibrations produced when cement
is pumped through a vibratory tool.
To combat these problems in getting
casing/liners to bottom, operators increasingly are using downhole vibratory
tools similar to those common in horizontal well drilling operations to run
casing strings. Downhole vibratory tools
break the static friction between the work
string and the wellbore or casing. The
tool has been used for extended laterals,
deviated wellbores, liner hanger systems,
cemented and noncemented wells, openhole packer systems, sleeve-systems, and
intermediate casing.
Seeking to consistently attain maximum casing depth while improving casing
run times in its extended-reach wells,

Kaiser-Francis Oil Company conducted
an eight-well field study in the
Niobrara/Codell play in Wyoming utilizing
vibratory casing technology. In this project,
a vibratory casing tool was placed in the
shoe track between the shoe and collar
to run casing in four wells, while casing
was run in the other four wells without a
vibratory tool. All eight wells were completed with 41⁄2-inch, 13.5-pound, P-110
liner in two-section laterals.
The data show up to a 121 percent
average increase in running speed while
rotating the liner in the hole using the vibratory casing tool, resulting in as much
as an average 55 percent decrease in rig
time compared with offset wells (Table
1). Importantly, less torque at higher
rotary speeds also was seen on the wells
using the vibratory tool.

include:
* Failure to get casing to bottom;
* Excessive time spent running casing
(directly impacting operational costs);
* High residual stress left in casing
and other downhole components (often
causing issues later in the life of the
well);
* Damage to casing and sleeve systems caused by rough handling during
trip in (including "hammering" casing
into the well using the rig blocks); and
* Overtorqued connections during
rotation to get casing in hole.
Proper cementing is an integral operation that has significant impact on the
completion process and is essential to
well longevity. Displacing the drilling
mud column with cement can be difficult
in long-lateral liner/casing applications
because casing typically favors the low
side of the wellbore. Casing eccentricity
also impedes mud displacement in the
narrow side of the annulus, permitting

Downhole Problems
The problems caused by excessive
casing-related friction in horizontal wells

TABLE 1
Performance Comparison of Niobrara/Codell Casing Running Field Test
Niobrara/Codell Well Comparisons
Well Name

Vibe Tool

Trip Length
Past
7 in. CS

Distance
Rotating

Hours
Rotating

Running
Speed
(ft/hr)

Max
Torque
(k ft-lbf)

Thread Type
41⁄2"
P-110

Lateral
Dip

Torque at TD
(K ft-lbf)
Drilling

Off Bottom

(Benchmark) Method 1: Buttress Threads - No Casing Tool
Biscayne

No

5,649 ft

4,333 ft

51.5 hrs

84.1

9.5

BTC

Down 100 ft

14(K ft-lbf)
60-RPM

11 (K ft-lbf)
60-RPM

Fury 1

No

3,805 ft

5,852 ft

57.5 hrs

101.8

11.9

BTC

Up 122 ft

14(K ft-lbf)
60-RPM

12 (K ft-lbf)
90-RPM

Shelby 1

No

4,236 ft

5,778 ft

21.0 hrs

275.1

12.0

BTC

Down 74 ft

14(K ft-lbf)
60-RPM

12 (K ft-lbf)
90-RPM

15,963 ft

130 hrs

Totals:

15963 ft ÷ 130 hrs = average 122.79 ft/hr

Method 2: High Torque Threads - No Casing Tool
Polara 1

No

4,090 ft

Improvement vs. Method 1

5,831 ft

26 hrs

224.3

11.5

14 (K ft-lbf)
11 (K ft-lbf)
50-RPM
60-RPM
83% Speed Increase= 102 ft/hr Gained

Hyd 521 SF

45% Run Time Decrease= 19 hrs Saved

Down 18 ft

Method 3: Casing Tool with High Torque Threads
Worland 1B

Yes

6,069 ft

3,911 ft

14.5 hrs

269.7

9.5

Ultra-SF

Down 147 ft

10 (K ft-lbf)
70-RPM

10 (K ft-lbf)
80-RPM

Camaro 1

Yes

4,576 ft

4,830 ft

19.0 hrs

254.2

9.5

Ultra-SF

Down 290 ft

13 (K ft-lbf)
60-RPM

9 (K ft-lbf)
60-RPM

Thunderbird 1A

Yes

4,174 ft

5,368 ft

23.0 hrs

233.4

9.0

Ultra-SF

Up 140 ft

12 (K ft-lbf)
50-RPM

9 (K ft-lbf)
80-RPM

Malibu 1

Yes

4,185 ft

5,707 ft

16.5 hrs

345.9

10.5

Hyd 521 SF

Down 18 ft

14 (K ft-lbf)
70-RPM

11 (K ft-lbf)
70-RPM

19,816 ft

73 hrs

Totals:

19816 ft ÷ 73 hrs = 271.45 ft/hr

Improvement vs. Method 1

55% Run Time Decrease= 23 hrs Saved

121% Speed Increase= 149 ft/hr Gained

Improvement vs. Method 2

17% Run Time Decrease= 4 hrs Saved

21% Speed Increase= 47.15 ft/hr Gained

**The following calculation was used to compare casing run times in Table 1:
The average distance rotating for all eight wells (5,201 feet) ÷ the average casing running speed (ft/hr) for each casing method.

SEPTEMBER 2016 61
American Oil and Gas Reporter - September 2016

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