BACKGROUND
Water is used to extract oil and gas through hydraulic fracturing. This results in large quantities of Produced Water that needs to be dealt with. Produced water has considerable management costs that could adversely affect the life of the well. Produced water handling practices must also be environmentally sound or the operator could face regulatory action. Disposal of water in an injection well has met with resistance from the local, state and federal levels.
SUMMARY OF TECHNOLOGY
The key aspect of this invention is the use of produced water to form a solid geopolymer phase. Geopolymers are a class of inorganic binders which are rigid, aluminosilicate, hydrated gels, charge-balanced by alkali cations such as Na+, K+, or Cs+. They are generally formed by reacting aluminosilicate powders (e.g. metakaolin, fly-ash) with aqueous alkali silicate solutions. Geopolymers can be fabricated using a range of oxide compositions, and can be represented by the formula aM2O.bAl2O3.cSiO2.xH2O (M=Na, K or Cs, and x can range from 4-35). The critical aspect of this invention is the optimal chemistry (to be developed through this proposal) such that the geopolymer precursor is in a liquid state (similar to “milk”) for reasonable time (at least 4-8 hours) and allows its reinjection as a fluid in the ground at high pressures (approximately 10,000-15,000 psi), following common industrial practices. The geopolymer precursor, when reinjected in the ground, will fill all the cracks and crevices. The ensuing geo-polymerization reaction will result in forming a “rock” like aluminosilicate phase, which will also bond with the rocks and shale.
POTENTIAL AREAS OF APPLICATION
MAIN ADVANTAGES
- Environmentally safe alternative to produced water disposal
- Lower cost
- Healing crack in soil and minimizes seismic activity
STAGE OF DEVELOPMENT
- There is a Proof of Concept for this technology.