Scope of Application:
Friction-reduced water, also known as
Slickwater, is an internationally popular fracturing fluid technology at
present. It is suitable for the exploitation and use of low permeability
reservoirs, especially the fracturing treatment of the shale gas.
Technical Principle:
Friction-reduced water is a fracturing
fluid system which is for med by adding into water a type of polymer and some
additives such as bactericide, surfactant and scale inhibitor. The company has
independently researched and developed the friction-reduced water system YL-JZ
with high performance through indoor optimization evaluation and field test.
System Performance and Characteristics
Characterized by its low viscosity, low
cost, no residue and slight pollution, this system can reduce the friction
effectively and has a friction reduction more than 30-70% compared to clear
water.
(1)Friction Reduction Performance:
The test indicates that the drag reduction
efficiency of the 0.03% YL-JZ has reached 75%.
Comparison Diagram of Friction Test on friction-reduced water
(2)Low Interfacial Tension
The developed efficient cleanup additive
YL-ZP2 can be characterized by low concentration and low surface and
interfacial tensions. The surface tension of 0.1% YL-ZP2 is 24. 86mN/m and the
interfacial tension is 2.83mN/m.
Diagram of Surface Tension Measurements of Friction-reduced Water
(3)The inhibition performance of shale
YL-F2 is a long-term and short-term
composite shale inhibitor, which is anti-swelling and can inhibit the migration
of clay particles.
(4)Antiscale Performance:
In consideration of high liquid
consumption, low flowback rate and long flowback cycle for shale fracturing
construction, the YL-HKWC-2 high-effective scale inhibitor has been added into
the YL-JZ system in order to prevent the friction-reduced water system from
scaling in the formation condition. The concentration 15mg/L has been adopted
so as to effectively prevent scaling.
(5)Sterilization performance:
The experiment shows that YL-SJ2 has good
compatibility with other additives such as surfactant and resistance reducing
agent and can kill bacteria efficiently.
Concentrationmg/L | Sterilization rate (%) | ||
SRB | TGB | FB | |
60 | 95.6 | / | 62 |
80 | 100 | 100 | 98.4 |
100 | / | 100 | 100 |
120 | 100 | 100 | 99.8 |
Service Ability and Performance:
As of June 2013, this system has been
applied to oil and gas fields fracturing for 35 wells and has realized
significant effect in increasing yield. There are 10 fracturing stages in the
horizontal section of one shale gas well with 15,772.5 m3 total fluid volume,
653 m3 sand added and 10-10.8 m3/min construction displacement. The test under
construction indicates that the performance of the companys friction-reduced
water is good.
Curve Chart of Frac Treatment in a Shale Gas Well