DESCRIPTION
The Ultra-PF System is a specialty
drill-in and completion fluid designed for use in potassium and/or
cesium formate brines. Standard Ultra-PF
Systems formulated with xanthan gum biopolymer and
Formatrol®, a proprietary starch derivative,
provide enhanced low shear rate viscosities and high
temperature-high pressure filtration control up to 330°F. The
thermal stability of Ultra-PF Systems may
be further increased to 360°F with the addition of Formate
Stabilizer,
Thermasal™-A, and
Thermasal-B. Fluid systems formulated in potassium
formate range in density from 9.5 to 13.0 lb/gal at low solids
levels, and up to 14.6 lb/gal with the addition of higher density
weighting solids. Cesium formate compositions reach densities of
17.5 lb/gal with a minimum concentration of solids. In addition to
drilling into the payzone, Ultra-PF can be
utilized in underreaming, lost circulation pills, and pre/post
gravel pack fluid loss pills.
FEATURES
- A propriety starch with excellent thermal stability utilized as
a filtration control additive
- Synergistic polymer blend yields improved static suspension as
well as pseudoplastic behavior under dynamic conditions
- No external heat source is required during mixing to obtain the
desired fluid rheological properties
- Bridging/weighting solids of calcium carbonate, iron carbonate,
or iron oxide may be utilized in the Ultra-PF System
- System can be used across a broad density range
- Thin, ultra-low permeability filter cake limits filtrate and
polymer invasion into the formation
BENEFITS
- Stable system properties up to 360°F
- Mixing time and costs are minimized
- Easier clean-up with low solids formulations due to ultra-thin
filter cake
| PRODUCT |
COMPONENTS |
FUNCTIONS |
|
Formavis Ultra
|
Xanthan gum biopolymer
|
Viscosifier
|
|
Formatrol
|
Derivatized starch
|
Fluid loss control additive
|
|
Ultra Carb
|
Sized calcium carbonate
|
Bridging particles
|
|
Formate Stabilizer
|
Polyglycol
|
Thermal stabilizer
|
|
Thermasal-A & B
|
Anhydrous salt and magnesia compound
|
Two component thermal stabilizing system
|
LOW SHEAR RATE VISCOSITIES (0.0636 sec-1) AND
FILTRATES
FOR VARIOUS POTASSIUM FORMATE/ULTRA-PF
SYSTEM DENSITIES
| SYSTEM |
PROPERTIES |
INITIAL |
HOT ROLL,
16 Hours
|
STATIC AGE,
16 Hours
|
|
10.5 lb/gal Calcium Carbonate
|
LSRV, cP
|
26,800
|
25,400
|
64,200
|
|
Filtrate, mL
|
6.0
|
5.5
|
7.0
|
|
11.5 lb/gal Calcium Carbonate
|
LSRV, cP
|
24,200
|
61,000
|
48,200
|
|
Filtrate, mL
|
6.8
|
8.3
|
7.3
|
|
12.4 lb/gal Calcium Carbonate
|
LSRV, cP
|
43,200
|
63,200
|
42,100
|
|
Filtrate, mL
|
5.0
|
6.5
|
5.0
|
|
14.6 lb/gal Hematite
|
LSRV, cP
|
71,500
|
69,200
|
66,500
|
|
Filtrate, mL
|
8.8
|
8.0
|
5.0
|
TEST PARAMETERS
- Rheological properties: 120°F
- Hot roll: 280°F
- Static age: 330°F
- HTHP test media: 750 mD saturated disk
- Filtrate (30 minutes): 330°F
- Pressure differential: 250 psi
LOW SHEAR RATE VISCOSITY
INITIAL YIELD AND STABILITY OF
VARIOUS FILTRATE REDUCERS IN 12.0 lb/gal KCOOH BRINE
| ADDITIVE (22.4 lb/bbl) |
LSRV (0.0636 sec-1) |
| INITIAL |
HOT ROLLED, 250°F, 16 Hours |
|
Formatrol
|
208,000
|
150,000
|
|
PAC
|
230,000
|
50,400
|
|
Starch Derivative No. 1
|
7,000
|
250,000
|
|
Starch Derivative No. 2
|
500
|
312,000
|
|
Starch Derivative No. 3
|
500
|
52,000
|
|
Starch Derivative No. 4
|
400
|
2,700
|