Permeability evaluation method of tight glutenite reservoir based on NMR dynamic cutoff theory
The tight glutenite reservoir of Qingshuihe Formation in deep southern margin of Junggar Basin is an important exploration area,and permeability is a key parameter to evaluate tight glutenite reservoir.In order to improve this kind of reservoir permeability calculation accuracy,this article is based on nuclear magnetic resonance experiment,analyse saturated water of tight glutenite core and centrifugal state nuclear magnetic resonance(NMR)transverse relaxation time(T2)spectrum,made clear occurrence pattern of fluid and fluid seepage rule in tight glutenite pore,put forward the deficiency of conventional NMR permeability calculation method,and propose the concept of dynamic cut-off value of NMR.Based on the NMR dynamic cut-off value,the reservoir pore space was divided into three parts:free fluid pore,capillary semi-bound pore and complete bound pore.Analyze the correlation of permeability and different pore types.The permeability of tight glutenite reservoirs is positively correlated with the free fluid porosity,the total porosity of nuclear magnetic,the geometric mean of T2 in capillary semi-bound pores,and negatively correlated with the fluid saturation of completely bound pores.A permeability model based on different pore types was constructed,and the relative error between the calculated permeability and the permeability of the core experiment was less than 9.0％.This method improves the accuracy of the permeability calculation of tight glutenite reservoirs,and has wide application prospects in the evaluation of tight glutenite reservoirs of Qingshuihe Formation in deep southern margin of Junggar Basin.
Junggar Basindeep southern margintight glutenitenuclear magnetic resonancedynamic cutoff valuepermeability
万方数据
维普
