A new approach for evaluating dual sweet spots, integrating geological and engineering factors, has been developed to improve production outcomes from tight gas reservoirs located within the LX block of China. This method addresses significant challenges associated with the heterogeneous nature of these reservoirs and the disconnect between engineering treatments and geological evaluations, which have often resulted in suboptimal development strategies.
The research, conducted by experts from the Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering at Yangtze University, introduces an evaluation method focusing on the Shihezi Formation. It emphasizes the utilization of post-frac production as the objective function, combining various metrics to generate a dual sweet spot index termed F-value. By applying the grey correlation method, researchers effectively quantified the weight coefficients attributed to both geological conditions and engineering parameters, formulating a comprehensive evaluation process.
This innovative model demonstrates practical applications for selecting well locations and optimizing fracturing designs. Preliminary results indicate not only strong correlations between the F-value and actual production rates but also highlight specific geological sections within the LX area as having distinct potential for gas extraction.
Key findings reveal the existence of optimal sections where the F-value exceeds 0.5, marking these areas as priority targets for resource development. Conversely, sections with F-values below 0.3 are categorized as inefficient zones, warranting minimal developmental attention. Enhanced evaluation precision ensures well deployment aligns closely with reservoir characteristics, improving overall extraction efficiency.
The dual sweet spot model incorporates geological parameters such as reservoir thickness, gas saturation, permeability, and fracture density alongside engineering factors like brittleness index and horizontal stress differences. Notably, layers He2, He5, and He6 have been recommended for future fracturing efforts, owing to their favorable conditions revealed by this advanced evaluation process.
The methodology employed signals significant relevance to the energy sector, particularly as the demand for unconventional resources rises. Tight gas remains at the forefront of exploration efforts due to its vast reserves, and optimizing the evaluation of such reservoirs can lead to improved output rates and prolonged field life.
Conclusively, this study not only strengthens the theoretical framework surrounding tight gas extraction but also offers practical guidance for future research. The dual sweet spot evaluation model stands as adaptive and can potentially be adjusted to various geological conditions worldwide, ensuring it meets the needs of contemporary resource exploration efforts.