Acoustic and electrical methods are commonly used to evaluate hydrate saturation based on P-wave velocity(Vp)and resistivity,respectively.We evaluate hydrate saturation using petrophysical parameters directly related ...Acoustic and electrical methods are commonly used to evaluate hydrate saturation based on P-wave velocity(Vp)and resistivity,respectively.We evaluate hydrate saturation using petrophysical parameters directly related to the presence of hydrates.Five petrophysical parameters sensitive to hydrate saturation were first analyzed using the equivalent medium rock physical model,logging intersection plots,and petrophysical parameter inversion.The simulated annealing global optimization method was then used to estimate the hydrate saturation profile in the Shenhu Area,China.The petrophysical parameters Vp,λρ,andλμ,which are associated with the rock elastic and shear moduli,are highly sensitive to hydrate saturation for an estimated saturation range of 0.1-0.44.This range is consistent with that obtained from the original well diameter curves.However,the parameters Vs andμρ,which are only related to the rock shear modulus,yield high hydrate saturation estimates of 0.22-0.43 and exhibit some deviations from the real-time data.Owing to its sensitivity,the Poisson’s ratio is least desired for hydrate evaluation among the studied parameters.The sensitivity of hydrate saturation depends on the petrophysical model used for studying hydrate physical properties and storage analysis.展开更多
基金The study is supported by the National Natural Science Foundation of China(Nos.91958206,41876053)the National Key Research and Development Plan(2017YFC0307401,2018YFC1405901)+1 种基金the Fund of Acoustics Science and Technology Laboratory(GK2050260214,GK2050260217,GK2050260218,KY10500180084,KY10500190031,6142108200202)Fundamental Research Funds for the Central Universities(HEUCFJ180503,201964016).
文摘Acoustic and electrical methods are commonly used to evaluate hydrate saturation based on P-wave velocity(Vp)and resistivity,respectively.We evaluate hydrate saturation using petrophysical parameters directly related to the presence of hydrates.Five petrophysical parameters sensitive to hydrate saturation were first analyzed using the equivalent medium rock physical model,logging intersection plots,and petrophysical parameter inversion.The simulated annealing global optimization method was then used to estimate the hydrate saturation profile in the Shenhu Area,China.The petrophysical parameters Vp,λρ,andλμ,which are associated with the rock elastic and shear moduli,are highly sensitive to hydrate saturation for an estimated saturation range of 0.1-0.44.This range is consistent with that obtained from the original well diameter curves.However,the parameters Vs andμρ,which are only related to the rock shear modulus,yield high hydrate saturation estimates of 0.22-0.43 and exhibit some deviations from the real-time data.Owing to its sensitivity,the Poisson’s ratio is least desired for hydrate evaluation among the studied parameters.The sensitivity of hydrate saturation depends on the petrophysical model used for studying hydrate physical properties and storage analysis.
