Abstract:

The Devonian reservoir in BEL structure in Algeria belongs to fractured tight reservoir with medium porosity and extralow permeability and has strong heterogeneity and fast facies change, which results in more difficulties in reservoir prediction. Based on the analysis of characteristics of sediment, structure and hydrocarbon-bearing property, it is considered that the sand body of Siegenian-Low reservoir is well developed and has better continuity, and can form favorable reservoir; the sand body of Siegenian-Med reservoir is less developed with poor continuity, and only several part can form reservoir; the sand body of Siegenian-Up reservoir is relatively developed with better continuity, and can form favorable reservoir. Based on seismic-sedimentary facies analysis, combined with techniques such as multi-attribute optimization, reservoir random simulation, pre-stack fracture prediction and pre-stack seismic attribute hydrocarbon detection, the favorable areas are comprehensively predicted, and appraisal well is proposed, in which good application results have been achieved. These techniques have been the key techniques for the reservoir prediction and description in Algeria, and even Libya and Tunisia.

Key words: water flooding development, dynamic variation, reservoir properties, influencing factors