Abstract:

Reservoir evaluation serves as a foundational aspect in the development of tight sandstone gas reservoirs, with the accuracy of these evaluations critically influencing potential development analyses. The selection of evaluation methodologies is pivotal in ensuring the reliability of development index predictions and the scientific integrity of adjustments and deployment strategies. Addressing the challenges inherent in evaluating tight sandstone gas reservoirs—such as numerous influencing factors, ambiguous controlling factors, unknown parameter sensitivity, and unquantified evaluation indices—this study develops a quantitative analysis model using the analytic hierarchy process（AHP）. This approach simplifies complex issues and quantifies qualitative aspects, facilitating a more structured evaluation. Utilizing geophysical data, logging interpretation, and geological fundamentals as criterion indices, the study constructs a judgment matrix to establish a quantitative evaluation model. This involves determining index weights, conducting consistency tests, and deriving a weight vector. The model is then validated through correlation analysis between the recoverable reserves, open flow, and evaluation values of actual wells. Findings demonstrate the method's reliability and further refine the criteria for reservoir classification. The evaluation indices defined through this research enhance the understanding of “sweet spots” for tight sandstone gas reservoir development within the same region, improve the precision of reservoir prediction, and aid in the strategic deployment of development activities. Ultimately, this study offers valuable insights and a methodological framework for the efficient development of similar gas reservoirs.

Key words: reservoir evaluation, tight sandstone, judgment matrix, parametric optimization, analytic hierarchy process