致密砂岩气藏定量表征技术新进展OA

Tight sandstone gas reservoirs are characterized by low porosity,low permeability,and strong heterogeneity.The conventional reservoir characterization techniques suffer from limited spatial coverage,low resolution and weak quantitative capability,and thus fail to meet the requirements of fine development and enhanced gas recovery.To this end,this paper systematically reviews the domestic and international achievements in the quantitative characterization of tight sandstone gas reservoirs.Synthesis and analysis are carried out focusing on five core technologies,including thin-reservoir prediction,reservoir architecture characterization,fluid identification,geological modeling-numerical simulation integration,and intelligent characterization.Furthermore,the evolutionary features of characterization technology system are summarized,the technical bottlenecks are identified,and the next technical development directions are pointed out.The following results are obtained.First,the characterization of tight sandstone gas reservoirs in the past 10 years exhibit three major shifts,including the shift of research objects from simple to complex reservoirs like water-bearing gas reservoirs and deep thin reservoirs,the shift of technical methods from qualitative description to multi-parameter quantitative characterization,and the upgrading of research scales from single reservoir depiction to whole-gas-reservoir integrated dynamic characterization.Second,substantial progresses have been made in high-resolution facies-controlled seismic inversion,multi-scale reservoir architecture dissection,multi-source mud logging and wireline logging integrated fluid identification,hierachical-collaboration-based 3D modeling,and machine-learning-based intelligent prediction.Their application in the Sulige and Qingyang Gasfields of the Ordos Basin effectively improves sandbody identification accuracy and reservoir drilling rate of horizontal well.Third,the next research directions of characterization technologies mainly include applying a multi-level coupling model spanning from nano-scale pore throats,centimeter-scale cores,meter-scale well logs,to kilometer-scale seismic data to accurately characterize the differences and intrinsic relationships among multi-scale reservoir features,establishing a gas reservoir model integrating reservoir,wellbore,and pipeline network to achieve full-life-cycle dynamic characterization of tight sandstone gas reservoirs,and comprehensively applying data-driven intelligent characterization technologies throughout the entire life-cycle of tight gas reservoir exploration,development and production.In conclusion,the innovations in gas reservoir characterization technologies will drive the digital and intelligent transformation of tight gas development.With the deep integration of high-performance computing,Internet of Things(IoT)and artificial intelligence(AI),gas reservoir characterization technologies are expected to break through existing theoretical boundaries within the next 3 to 5 years,providing core support for the efficient development of unconventional resources and the energy security globally.