Form-A-Set Ak
Form-A-Set* AK lost-circulation-control material is a blend of polymers and
fibrous materials designed to plug matrix and fractured zones.
When combined with Duo-Vis* biopolymer and activated with a combination of Form-A-Set XL crosslinking agent along with time and
temperature, Form-A-Set AK produces a firm, rubbery, ductile plug that effectively prevents loss of fluid to the formation. The fibrous material
in the Form-A-Set AK package is a mixture of particle sizes designed to plug fine-to-medium sized, deep fractures and faults.
Typical Physical Properties
Physical appearance������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������ Light tan powder
Specific gravity������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 1.2
Bulk density��������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������35 lb/ft3 (550 kg/m3)
Applications
Form-A-Set AK fluid-loss-control plug can be used to stop partial and matrix losses in any water, oil or synthetic-base drilling fluid system.
Form-A-Set AK can be mixed in freshwater, seawater or saltwater up to saturation, though mixing in saltwater will retard set times. Form-A-Set
AK can be used in any application where a squeeze plug is beneficial and a needs a smaller particle-size distribution of bridging material than
does Form-A-Set. The smaller particles enhance the ability of the material to penetrate a porous or fractured zone.
Form-A-Set AK lost-circulation material does not contain a crosslinking agent, thus allowing for more control than the Form-A-Set product. The
plug can be mixed and stored on location as a contingency, significantly reducing response time.
Once losses are encountered, the plug is activated by adding Form-A-Set XL crosslinker (see enclosed tables for mixing concentration).
The Form-A-Set AK plug subsequently is spotted across and above the loss zone, and squeezed into place. Depending on the loss rate and
whether the losses are to fractures, vugs, etc., sufficient Form-A-Set AK should be applied to completely cover the expected loss zone, along
with a 100% excess to squeeze into the borehole breech.
Retarder/Accelerator
Form-A-Set Ret retarder should be used with applications above 105°F (38°C) or when pill temperature exceeds 105 °F (38°C) when mixing.
Form-A-Set Ret must be added to the plug before adding Form-A-Set XL crosslinking agent. If the plug is to be used immediately, Form-A-Set Ret
may be added to the water prior to the addition of Form-A-Set AK. Otherwise, it should be mixed into the plug just before adding Form-A-Set XL.
Use FASware* to determine the Form-A-Set Ret required. Table 1 provides the typical concentrations. For best results, pilot test for sufficient
retarder concentration.
Table 1 – Form-A-Set retarder concentration for Form-A-Set AK
°F
Up to 105
105-123
123-140
140-155
155-190
190-250
250+
Bottomhole Temperature
°C
Up to 38
38 – 50
50 - 55
55 – 68
68 – 88
88 - 120
122+
Form-A-Set Ret
lb/bbl of water
kg/m3 of water
----2
6
4
12
6
17
10
29
16
46
FASware and lab testing recommended
Note: Form-A-Set Ret retarder concentration is proportionate to the water volume.
Form-A-Set ACC accelerator crosslinks and speeds up the setting of the plug. It is used when placement temperatures are below 60°F (15.6°C).
To avoid over treatment, exercise caution when adding the accelerator. Use 0.3 lb/bbl (0.9 kg/m3) Form-A-Set ACC accelerator, proportional to
the water volume. Form-A-Set ACC accelerator should be added after adding Form-A-Set XL. Diluting the Form-A-Set ACC in 5 to 10 gal (20-40 L)
of water makes it easier to blend in the Form-A-Set XL.
Unweighted Slurry Mixing Instructions
To mix an unweighted pill of Form-A-Set AK plug, use a clean pit or blending tank.
1.Fill the pit with 0.93 bbl (0.93 m3) of fresh water for each barrel (cubic meter) of pill.
2.Add 1.4 lb/bbl (0.7 kg/m3), one-half of the total Duo-Vis
3.Add 23 lb/bbl (11.6 kg/m3) Form-A-Set AK material
4.Add the remaining Duo-Vis biopolymer
5.If the plug is to be held for more than 1 day, treat with 0.1 gal/bbl (2 L/m3) 25% glutaraldehyde biocide and 0.1 lb/bbl (3 kg/m3) X-Cide 207
or other isothiazalone product. Failure to include biocides can affect performance of the plug. If biocides are unavailable, consider using
Form-A-Set AKX.
6.When ready to pump, add Form-A-Set Ret if required.
7.Add Form-A-Set XL and mix 5 min. If needed, add Form-A-Set ACC after Form-A-Set XL.
Weighted Slurry Mixing Instructions
Use FASware to determine the optimum formulation of Form-A-Set AK slurries with barite weighting agent. Table 2 presents the typical blends.
Mixing order should be:
1.Add one-half of the Duo-Vis biopolymer
2.Add one-half the Form-A-Set AK material
3.Add the M-I Bar barite
4.Add the remaining Form-A-Set AK material
5.Add the remaining Duo-Vis biopolymer
6.If the plug is to be held for more than one day, treat with 0.1 gal/bbl (2 L/m3) 25% glutaraldehyde biocide and 0.1 lb/bbl (3 kg/m3) X-Cide 207.
Failure to include biocides can affect performance of the plug. If biocides are unavailable, consider using Form-A-Set AKX.
7.When ready to pump, add Form-A-Set Ret, if required
8.Add Form-A-Set XL and mix 5 min.. In cold applications, add Form-A-Set ACC after Form-A-Set XL.
Note: Use only ester or alcohol-base defoamer such as Defoam-A*. Aluminum-stearate based defoamers may interfere with set time.
Pumping Instructions
Once losses are encountered, add Form-A-Set Ret retarder, if required, and mix thoroughly for 5 min. Add the proper amount of Form-A-Set XL
crosslinker to the pill, mix thoroughly for 5 min., and pump immediately afterwards.
When used in a non-aqueous drilling fluid, pump approximately 20 to 30 bbl (3 to 5 m3) of viscous water or water-based mud as spacers in front
of and behind the pill. A 2 lb/bbl (5.7 kg/m3) Duo-Vis slurry weighted up to the same density makes a good spacer. Aqueous fluids may require
spacers if they have high pH or are otherwise incompatible.
Depending on loss rate, spot the pill across and above the loss zone while pulling out of the hole to a safe location. Keep the pill below the bit
to avoid it mixing with wellbore fluids. This pill crosslinks and sets up as a flexible plug. Even if losses have stopped, it is important not to leave
any pill in the pipe. Do not stop pumping while the pill is in the drillstring. It is important to pump at least 10 bbl (2m3) of spacer or water-based
mud to clear the drillstring.
Watch for any sign of the pill reaching the loss zone, such as increased pressure or improved return flow. To begin squeezing, pull above the
pill and close the annular preventer. Typically two-thirds to three-quarters of the pill is squeezed away. If pressure is noted, hold for at least
three hours to obtain a firm set of the pill.
Table 2 – Mixing Concentrations
Density
lb/gal
8.34
9.0
9.5
10.0
10.5
11.0
11.5
12.0
12.5
13.0
13.5
14.0
14.5
15.0
15.5
16.0
16.5
17.0
17.5
18.0
s.g.
1.00
1.08
1.14
1.20
1.26
1.32
1.38
1.44
1.50
1.56
1.62
1.68
1.74
1.80
1.86
1.92
1.98
2.04
2.10
2.16
Water
bbl/bbl
0.93
0.90
0.89
0.87
0.85
0.83
0.82
0.80
0.78
0.765
0.748
0.730
0.713
0.696
0.679
0.661
0.644
0.627
0.611
0.594
m3
0.93
0.90
0.89
0.87
0.85
0.83
0.82
0.80
0.78
0.77
0.75
0.73
0.71
0.70
0.68
0.66
0.64
0.63
0.61
0.59
Duo-VisTM
lb/bbl
2.77
2.71
2.65
2.60
2.55
2.10
1.80
1.60
1.34
1.13
0.95
0.78
0.64
0.51
0.00
0.00
0.00
0.00
0.00
0.00
kg/m3
7.89
7.72
7.55
7.41
7.27
5.99
5.13
4.56
3.82
3.22
2.71
2.22
1.82
1.45
0.00
0.00
0.00
0.00
0.00
0.00
Form-A-Set AKTM
lb/bbl
23.12
22.55
22.11
21.68
21.25
20.85
20.40
19.97
19.55
19.12
18.69
18.26
17.83
17.40
16.97
16.54
16.10
15.67
15.24
14.80
kg/m3
65.89
64.27
63.01
61.79
60.56
59.42
58.14
56.91
55.72
54.49
53.27
52.04
50.82
49.59
48.36
47.14
45.89
44.66
43.43
42.18
NOTE: FASware can provide more precise formulations.
Form-A-Set XLTM
lb/bbl
5.0
4.75
4.75
4.50
4.50
4.25
4.25
4.00
4.00
3.75
3.75
3.50
3.50
3.25
3.25
3.00
3.00
2.75
2.75
2.50
kg/m3
14.25
13.54
13.54
12.83
12.83
12.11
12.11
11.40
11.40
10.69
10.69
9.98
9.98
9.26
9.26
8.55
8.55
7.84
7.84
7.13
M-I Bar®
lb/bbl
0
37.2
64.8
92.3
119.9
147.6
175.3
202.9
230.6
258.2
285.8
313.4
341.0
368.6
396.2
423.8
451.3
478.9
506.4
534.0
kg/m3
0.0
106.0
184.7
263.1
341.7
420.7
499.6
578.3
657.2
735.9
814.5
893.2
971.9
1050.5
1129.2
1207.8
1286.2
1364.9
1443.2
1521.9
Form-A-Set AK Mixing Example
Two hundred barrels (32 m3) of a 14 lb/gal (1680 kg/m3) Form-a-Set AK plug is needed to seal a fracture in a 190°F (88°C) formation.
As shown in Table 1, for the formation temperature of 190°F (88°C), the Form-A-Set RET concentration should be 10 lb/bbl (29 kg/m3). Using the
Mixing Concentrations in Table 2, the formulation and mixing order is as follows:
1.Water: 0.730 barrel/bbl x 200 = 146 bbl (23 m3)
2.Duo-Vis biopolymer: 0.39 lb/bbl (half of the total required) x 200 = 78 lb (35 kg)
3.Form-A-Set AK material: 9.13 lb/bbl (half of the total required) x 200 = 1826 lb (828 kg)
4.M-I Bar barite: 313.4 lb/bbl x 200 = 62,680 lb (28.4 tonne)
5.Form-A-Set AK material: (the second half of the total required) = 1826 lb (828 kg)
6.Duo-Vis biopolymer: (the second half of the total required) = 78 lb (35 kg)
7.Form-A-Set Ret retarder: 10 lb/bbl (29 kg/m3) proportioned to water volume:
(10 lb/bbl of water X 0.73 bbl water/bbl of pill = 7.3 lb/bbl of pill) x 200 = 146 lb (66 kg)
8.Form-A-Set XL crosslinker: 3.5 lb/bbl x 200 = 70 lb (32 kg)
Note: FASware* provides more exact formulations.
Advantages
•  Form-A-Set AK additive contains only the polymer and lost-circulation material. It can be mixed and stored on location before losses are
encountered to reduce response time. Proper biocidal treatments are required.
•  Because of its increased polymer loading and the smaller size of the fibrous material, the Form-A-Set AK fluid loss control plug has a much
firmer set than the conventional Form-A-Set plug
•  Because of the firmer set, Form-A-Set AK plug has a wider range of applications. These applications range from matrix to partial losses of
20-100 bbl/hr (3 to 16 m3/hr).
•  The material also can be used to shut off water in non-productive zones and in gravel consolidation
Limitations
•  Static conditions are required for the pill to completely set up, so Form-A-Set AKX is best used to cure matrix and partial losses or as part of
a tandem pill to cure severe losses
•  A Form-A-Set AK plug does not degrade in the well bore even at extended times. It is not acid soluble and caution should be exercised when
it is used in or near the production zone
•  Pilot testing is recommended to assure set time/temperature under field conditions, especially when made up in brine. Contact Technical
Services for procedures.
•  Lab testing for set time and thermal stability is recommended when temperatures exceed 250°F (120 °C)
•  Pilot/lab testing is recommended when density exceeds 16.0 lb/gal (1.9 sg)
•  For all plugs to be held for 24 hours or longer, include 0.1 lb/bbl (0.3 kg/m3) of X-Cide 207 or other isothiazalone biocide and 0.1 gal/bbl (2 L/m3)
25% glutaraldehyde biocide
Toxicity and Handling
Bioassay information is available upon request.
Handle as an industrial chemical, wearing protective equipment and observing the precautions described in the Material Safety Data Sheet
(MSDS).
Packaging and Storage
Form-A-Set AK material is packaged in 47-lb (21.3-kg) sacks or 25-lb (11.3-kg) sacks.
Form-A-Set Ret retarder is packaged in 5 gal (18.9-L) cans containing 55-lb (24.6-kg) of product.
Form-A-Set ACC accelerator is packaged in 1 qt (0.946-L) containers containing 3-lb (1.4-kg) of product.
Form-A-Set XL crosslinker is packaged in a 50-lb (22.7-kg) sack enclosed in a 12-gal (45.4-L) cardboard can.
Store these products in a dry, well-ventilated area. Keep container closed. Store away from incompatibles. Follow safe warehousing practices
regarding palletizing, banding, shrink-wrapping and/or stacking.
This information is supplied solely for informational purposes and M-I SWACO makes no guarantees or
warranties, either expressed or implied, with respect to the accuracy and use of this data. All product
warranties and guarantees shall be governed by the Standard Terms of Sale. Nothing in this document
is legal advice or is a substitute for competent legal advice.
©2010 M-I L.L.C. All rights reserved.* Mark of M-I L.L.C.
FPB.0611.1010.R2 (E)
P.O. Box 42842
Houston, Texas 77242-2842
www.miswaco.slb.com
E-mail: questions@miswaco.slb.com