Petroleum Reservoir Evaluation and Development ›› 2024, Vol. 14 ›› Issue (2): 207-215.doi: 10.13809/j.cnki.cn32-1825/te.2024.02.006

• Volcanic Gas Reservoir • Previous Articles     Next Articles

Comparison, optimization and application of multiple prestack inversion algorithm for intermediate basic volcanic reservoirs: A case study of Huoshiling Formation in Chaganhua area

LI Ruilei(),CAO Lei(),FAN Xuepei,FENG Xiaohui,LI Ning   

  1. Sinopec Northeast Oil & Gas Company, Changchun, Jilin 130062, China
  • Received:2023-12-25 Online:2024-04-26 Published:2024-05-07
  • Contact: CAO Lei E-mail:lirl.dbsj@sinopec.com;caol.dbsj@sinopec.com

Abstract:

Currently, the most widely used pre-stack simultaneous inversion algorithm is based on the Zoeppritz equation approximation of isotropic horizontal media. This method, however, encounters challenges in medium-basic volcanic reservoirs characterized by rapid lateral lithological changes and vertical multi-period stacking. In such environments, tuffs and sedimentary tuffs exhibit similar logging and geophysical responses, complicating the distinction of lithology and physical properties of volcanic rocks through pre-stack simultaneous inversion. To address these challenges, qualitative analyses were conducted on the seismic response characteristics of volcanic reservoirs using convolutional model forward modeling. Additionally, well rock physics was employed for physical analyses of lithology and sensitive parameters pertinent to volcanic reservoirs. Comparative analyses of six binomial and trinomial pre-stack inverse algorithms, aimed at approximating the Zoeppritz equation in the specific area, were conducted through model calculations and actual data assessments. Based on these comprehensive analyses, the approximate algorithms developed by SMITH & GIDLOW and FATTI were identified as preferable choices. These algorithms use the reflection coefficients of P-wave impedance, S-wave impedance, and density as inputs for pre-stack inversion. The inversion results for P-wave impedance were utilized to predict the presence of local tuff, while the inversion outcomes for density were employed to ascertain the effective reservoir physical properties. The efficacy of this approach was validated through the deployment of an evaluation well and a horizontal well, which yielded predicted compliance rates of 76.0% and 84.6%, respectively.

Key words: pre-stack inversion, volcanic rock, seismic response, rock petrophysic, petrophysical property prediction

CLC Number: 

  • TE122