Associative Non-Crosslinked Fracturing Fluid Technology
The Structure of Solution
3.3.2 Thickening Property of Thickener
The soluble thickener had good thickening property and function of surface activity in water.
Synergistic Action of Thickener in Adjuvant and Salt
There was an optimal ratio between main agent and adjuvant; the viscosity of solution would not decrease when the salinity concentrations increased.
Stability of Temperature and Anti-corrosion
Without bacteria erosion, the fracturing fluid was characterized by good anti-septic effect, which was beneficial to field application.
The Effect of Shear Rate
It could be found from the results that the solution crucially depended on the temperature and shearing rate.
Yield Stress
(a)The yield stress test of the GRF1003 solution, and no yielding phenomenon was observed
(b) The yield stress test of the GRF1505 solution, and no yielding phenomenon was observed
(c) The yield stress test of the GRF2007 solution, and no yielding phenomenon was observed
(d) The yield stress test of the GRF2510 solution, and the yielding stress was observed
(e) The yield stress test of the GRF0.7 solution, and the yielding stress was observed
The Results of Yield Stress Tests (a~e)
The Yield Points of Series of GRF-1H Solutions with Different Concentration
The concentration of the GRF-1H solution increased 0.1%, the yield stress will increase 1.46 GPa.
High-temperature Rheological Properties
Viscoelasticity
Gel breaking performance and surface activity
The Viscosity of Fracturing Fluid after Different Gel Breaking Time
| Sample ID | Gel breaking temperature (℃) | CFB-130 (%) | viscosity of fluid broken /mPa·s | ||||
| 0h | 1.0h | 2.0h | 3.0h | 4.0h | |||
1# | 80 | 0.05 | 105 | 63 | 42 | 15 | 3.2 |
2# | 90 | 0.04 | 98 | 58 | 37 | 18 | 2.5 |
3# | 100 | 0.03 | 102 | 60 | 35 | 15 | 2.0 |
4# | 120 | 0.01 | 118 | 72 | 33 | 14 | 1.5 |
5# | 130 | 0.01 | 125 | 65 | 35 | 15 | 1.5 |
(Note: main agent (0.7%)+ auxiliary (0.015%)，other main agent and auxiliary:(0.5%+ 0.013%))
Table 3-9 The Surface and Interfacial Tension of Colloid（25.94/℃）
Sample ID of fracturing fluid | 1# | 2# | 3# | 4# | 5# |
surface tension （mN/m） | 27.52 | 27.13 | 26.82 | 26.65 | 25.14 |
interfacial tension （mN/m） | 0.68 | 0.62 | 0.53 | 0.42 | 0.35 |
Prop-pant bed Deposition Flowing Damage
Regular fracturing fluid caused much damage to flow conductivity of propped fracture. After gel breaking liquid of the clean fracturing fluid flowed through prop-pant bed deposition, the retention of flow conductivity is higher than 90%.
Sand-carrying Capability and Friction Coefficient
It could be found that the sand-carrying capability of this system was still very good even at very low viscosity, and its Darcy-Webster's friction coefficient was lower than guar gum fracturing fluid under the same conditions.
● The structure of the new solution is reversible that its structure is disintegrated at high shear rate and reformed after the shear rate reduced.
● It is beneficial to reduce construction friction, tubular column (or coiled tubing） fracturing.
Shear reversibility
After pipeline shearing, the AV of guar gum fracturing fluid was very low, however, non-crosslinked fracturing fluid still maintained a higher visco-elasticy.
Fracturing Fluid Series
Fracturing Fluid Applied in Oilfield
