FRAC-PAK

Function

A unique new product used to cure severe and total loss of circulation in synthetic, diesel and water muds.


General Description

A mixture of inert material and cellulose fiber used to prepare a high solids pill to be squeezed into loss circulation zones. Once in place in a loss zone, the liquid is squeezed out leaving behind a solid plug.


Product Benefits

  • Eliminates need to maintain LCM in total mud system.
  • Cures lost circulation rather that temporarily reducing losses.
  • Eliminates risk of side-tracking such as occurs with cementing.
  • Can be acidized if necessary.

Product Description

  • Color: Off white
  • Form: Fine Powder
  • Specific Gravity: 2.0
  • Bulk Density: 12-15 lbs./cu. ft.
  • pH: 6-8
  • Packaging: 25 lb 3-ply bag w/poly liner

Typical Treatment:

  1. Mix 50-100 bbl pill containing 50-100 bl/bbl of material. Mix in water (oil can be used) and add barite to obtain desired density.
  2. Squeeze into loss zone and hold pressure for 10-15 minutes.
  3. Pull up to safe place for 2 hours and resume operation.

Mixing & Spotting Procedure:

1. Ideally enough slurry should be available to cover all potential loss zones, and 50% excess for squeezing operations. Remember that this is a mechanical set pill and the finished product could be appreciably less than 50% of what you started with.

2. No special equipment is needed to mix or pump the FRAC-PAK slurries. The slurry can be mixed in a clean uncontaminated mud pit and pumped with rig pumps. It is best to physically monitor the volume of slurry pumped from the mixing tank, then reset the stroke counter to zero to count the strokes to place the slurry. This gives better control and insures the slurry is properly picked up and spotted.

3. It is generally best to begin with 80% of the liquid volume of fluid (as per tables 1,2,or 3).

To the fluid add:
a. 1 - 2 defoamer when using water;
b. all the FRAC-PAK;
c. barite;
d. remainder of the fluid.
When mixing in diesel or oil mud, additional wetting agent is required. Always pilot test for proper concentration.
When mixing in fresh or salt water, an additional thinner may be required. Always pilot test for proper concentration.


4. The slurry should be weighted to the same as the drilling fluid in the hole.

5. An additional 5 to 20 ppb medium size LCM will often be beneficial depending upon hole conditions. To avoid plugging the drill string, be certain that any additional LCM is smaller than any restrictions in the drill string.

6. Place the bottom of the drill pipe or bit at depth that will allow the slurry to clear the drill string plus 5 bbls of slurry.

7. Pump the slurry at 2 bbls per minute until slurry plus 5 bbls clears the drill string.

8. Pump approximately 20% of slurry into thief zone at 1 bbl/min.

9. Shut down and observe well. Before beginning the hesitation squeeze, check the annulus. If no fluid can be seen, attempt to fill the backside.

10. Close the annular BOP and begin pumping the hesitation squeeze down the backside at .25 to .5 bbls/min. in 5 bbls increments or when a pressure of 50 psi is obtained discontinue pumping for 15 minutes. Repeat this procedure until 50 psi can be maintained, and then attempt at progressively higher pressures in 25 psi increments. With this hesitation squeeze method there will be a pressure bleed off each time the pump is stopped. However, with each successive squeeze, the pressure should stabilize at a higher level.

11. When the maximum holding pressure is obtained, shut down and wait for four hours.

12. Bleed pressure from annulus slowly, and then circulate any water/oil and remaining FRAC-PAK out of the hole.

13. Begin staging in the hole slowly monitoring the weight indicator, and checking for bridges. Wash to bottom drilling any FRAC-PAK plug encountered. FRAC-PAK will not set up like cement, so there is no danger of sidetracking the hole.

Additional FRAC-PAK Suggestions:

  • Do not contaminate FRAC-PAK slurry with low fluid-loss mud or fluid loss additives.
  • Do not hurry to build squeeze pressure. Patience and time are necessary to obtain a successful squeeze.
  • Do not mix a weighted slurry too far in advance of using it. All weighted fluids are subject to barite settling with time.

Slurry Formulations

TABLE I
Formula for preparing one barrel of FRAC-PAK weighted slurry with fresh water, bay water or seawater. A thinner may be required with this formula.

 

Density
 FRAC-PAK
 Barite
 Water
Lb./Gal
 Lb.
  Sack
 Bbl.
 9.0
 100
 0
 .89
 10.0 100 0.6 .86
 11.0 94 1.2 .82
 12.0 84 1.8 .79
 13.0 78 2.3 .76
 14.0 70 2.9 .72
 15.0 62 3.5 .69
 16.0 56 4.0 .65
 17.0 48 4.6 .62
 18.0 44 5.2 .58
 19.0 34 5.8 .54

 

TABLE II
Formula for preparing one barrel of FRAC-PAK weighted slurry with saturated salt water. A thinner may be required with this formula.

Density
 FRAC-PAK
 Barite
 Water
Lb./Gal
 Lb.
  Sack
 Bbl.
   
 
 10.5 100 0 .94
 11.0 100.3 .91
 12.0 89.9 .88
 13.0 831.6 .85
 14.0 772.2 .81
 15.0 712.8 .77
 16.0 653.4 .74
 17.0 594.0 .70
 18.0 524.6 .66
 19.0 465.2 .62

 


*TABLE III
Formula for preparing one barrel of FRAC-PAK weighted slurry with 7.0 ppg base oil.

 Density
Frac-PAK
BariteOil
 Lb./GalLb.
Sack
Bbl.
 8.088
0.1
0.82
 9.0 82 0.6 .80
 10.0 75 1.1 .78
 11.0 701.7
 .75
 12.0 64 2.2 .72
 13.0 60 2.8 .69
 14.0 54 3.3 .67
 15.0 48 3.8 .65
 16.0 44 4.4 .62
 17.0 38 4.9 .60
 18.0 32 5.5 .57


*A wetting agent is required with this formula. Pilot test is necessary to determine quantity of wetting agent, to achieve a free flowing slurry.


The major key to a successful FRAC-PAK job is placing the slurry at the proper location in the wellbore so the liquid phase can be properly squeezed from the slurry leaving behind the reinforced solid plug.