The oil and gas industry faces unique challenges when it its to extracting resources from low permeability reservoirs, where irreducible water saturation severely hampers oil displacement. A recent study has unveiled promising advancements using ultrasonic technology to tackle this issue.
Researchers from the Key Laboratory of Sound Field-Assisted Oil and Gas Exploitation at Puyang have developed and tested ultrasonic generators to explore their effect on irreducible water saturation. They conducted experiments using natural low-permeability siltstone cores sourced from the Zhongyuan Oilfield, with kerosene as the simulated oil.
Ultrasound has emerged as a potential solution, enhancing oil recovery by reducing the saturation of irreducible water. Experiments demonstrated varying effects across different ultrasonic frequencies, with optimal results observed between 17 kHz and 125 kHz. When ultrasonic power increased, the reduction of irreducible water saturation was noted to be more effective, compensatory even when ultrasonic frequencies rose. The results indicate the complexity of the relationship between frequency and saturation reduction.
Using the ultrasonic treatment at 400 W and 25 kHz for 20 minutes at 25 °C, researchers achieved notable reductions of irreducible water saturation. For example, they found significant differences when comparing water saturation levels before and after ultrasonic treatment—supporting the notion of ultrasound's efficacy.
Temperature also plays a pivotal role. While the effectiveness of ultrasound diminished at higher temperatures, researchers found ultrasound still improved saturation under elevated temperatures, indicating versatility. The most pronounced results occurred at lower temperatures, with irreducible water saturation reduced by as much as 9.26%—highlighting low temperature conditions as optimal for ultrasonic applications.
These findings bear relevance for future oil recovery strategies, especially as the demand for efficient exploitation of challenging reservoir scenarios intensifies. By leveraging ultrasonic technology, the study signifies potential pathways for enhancing the economic viability of low permeability hydrocarbon reservoirs.
Multipronged experimental setups were established to study ultrasonic efficacy, exploring how different frequencies, power levels, and treatment times influenced irreducible water saturation. Results illustrated the relationship between ultrasonic action and the changes to the inner water film structure, which proved key to fluid flow improvements.
This innovative research opens avenues for engineers and scientists to implement ultrasound for optimizing oil around low permeability reservoirs. Given the cost and technical challenges associated with traditional extraction methods, the systematic application of ultrasonic technology may represent the future's frontier for enhanced oil recovery.
