:py:mod:`rockphypy.Perm` ======================== .. py:module:: rockphypy.Perm .. autoapi-nested-parse:: Recreation and modifcations of the Permeabilities models in Rock physics handbook matlab tools. .. !! processed by numpydoc !! Module Contents --------------- Classes ~~~~~~~ .. autoapisummary:: rockphypy.Perm.Permeability .. py:class:: Permeability Different permeability models. .. !! processed by numpydoc !! .. py:method:: Kozeny_Carman(phi, d) :staticmethod: Describe the permeability in a porous medium using Kozeny-Carman equation assuming the turtuosity tau=sqrt(2), 1/B=2.5 for unconsolidated monomodal sphere pack. :param phi: porosity :type phi: float or array-like :param d: pore diameter in m. :type d: float .. rubric:: Examples >>> phi= np.linspace(0.01,0.35,100) >>> d= 250 >>> k= Kozeny_Carman(phi, d) >>> plt.semilogy(phi, k ) :returns: *float or array-like* -- k (m^2): the resulting permeability is in the same units as d^2 .. !! processed by numpydoc !! .. py:method:: Kozeny_Carman_Percolation(phi, phic, d, B) :staticmethod: The Kozeny−Carman relations incorporating the percolation effect :param phi: porosity :type phi: float or array-like :param phic: percolation porosity :type phic: float :param d: pore diameter :type d: float :param B: geometric factor that partly accounts for the irregularities of pore shapes. :type B: float :returns: *float or array-like* -- k (m^2): the resulting permeability is in the same units as d^2 .. !! processed by numpydoc !! .. py:method:: Owolabi(phi, Swi) :staticmethod: Estimate the permeability in uncosonlidated sands of Pleistocene to Oligocene age in Eastern Niger Delta from log derived porosityand irreducible water saturation. :param phi: porosity :type phi: float or array-like :param Swi: irreducible water-saturation from welllogs :type Swi: float or array-like :returns: *float or array-like* -- k_oil, k_gas: permeabilities in mD for oil and gas sand reservoir, respectively .. !! processed by numpydoc !! .. py:method:: Perm_logs(phi, Swi) :staticmethod: Various empirical correlations of between permeability, porosity and irreducible water-saturation from welllogs. Models includs Tixier, Timur, Coates and Coates-Dumanoir. :param phi: porosity :type phi: float or array-like :param Swi: irreducible water-saturation from welllogs :type Swi: float or array-like :returns: * *float or array-like* -- k_tixier, k_Timur , k_coates, k_coates_Dumanoir: different permeability estimations, in the unit of mD * *Assumptions* * *-----------* * *- The functional forms used in these equations have to be calibrated, whenever possible, to site-specific data.* * *- The rock is isotropic.* * *- Fluid-bearing rock is completely saturated.* .. !! processed by numpydoc !! .. py:method:: Panda_Lake(d, C, S, tau, phi) :staticmethod: Modified Kozeny-carman relation incorpating the contribution of grain size variation and sorting using Manmath N. Panda and Larry W. Lake relation. :param d: mean particles size in um. :type d: float :param C: coefficient of variation of particles size distribution :type C: float :param S: skewness of particles size distribution :type S: float :param tau: tortuosity factor :type tau: float :param phi: porosity :type phi: float or array-like :returns: *float or array-like* -- k (md): permeability .. rubric:: References - Estimation of Single-Phase permeability from parameters of particle-Size Distribution, Manmath N. Panda and Larry W. Lake, AAPG 1994. .. !! processed by numpydoc !! .. py:method:: Panda_Lake_cem(phi, d) :staticmethod: Quantify the effects of cements on the single phase permeability estimate of unconsolidated sand using Panda & Lake model :param phi: porosity :type phi: float or array-like :param d: mean particles size in um :type d: float :returns: *float or array-like* -- k (md): permeability .. !! processed by numpydoc !! .. py:method:: Revil(phi, d) :staticmethod: Estimate permeability in very shaly rock using Revil et al. 1997 :param phi: porosity :type phi: float or array-like :param d: mean particles size in um :type d: float :returns: *float or array-like* -- k (md): permeability .. !! processed by numpydoc !! .. py:method:: Fredrich(phi, d, b) :staticmethod: Compute permability considering Pore Geometry and Transport Properties of Fontainebleau Sandstone :param phi: porosity>10% :type phi: float or array-like :param d: _description_ :type d: float :param b: shape factor b is equal to 2 for circular tubes and equal to 3 for cracks. :type b: float :returns: * *float or array-like* -- k (md): permeability * *References* -- ---------- * *- Fredrich, J. T., Greaves, K. H., & Martin, J. W. (1993, December). Pore geometry and transport properties of Fontainebleau sandstone. In International journal of rock mechanics and mining sciences & geomechanics abstracts (Vol. 30, No. 7, pp. 691-697). Pergamon.* .. !! processed by numpydoc !! .. py:method:: Bloch(S, C, D) :staticmethod: Predict porosity and permeability in sandstones prior to drilling using Bloch empirical relations obtain in Yacheng field. :param S: Trask sorting coefficient :type S: float :param C: Rigid grain content in frac :type C: float :param D: Grain size in mm :type D: float :returns: *float or array-like* -- phi, k: porosity (frac) and permeability (mD), respectively .. !! processed by numpydoc !! .. py:method:: Bernabe(phi, crf, w, r) :staticmethod: Bernabe models permit to compute the permeability and porosity of strongly pressure dependent pores such as cracks and approximately constant pores associated with tubes and nodal pores. :param phi: total porosity :type phi: float or array-like :param crf: crack fraction in pore volume :type crf: float :param w: width or aperture of the equivalent crack in um :type w: float :param r: radius of the tube in um :type r: float :returns: * *float or array-like* -- k (md): total permeability * *References* -- ---------- * *- Bernabe, Y. (1991). Pore geometry and pressure dependence of the transport properties in sandstones. Geophysics, 56(4), 436-446.* .. !! processed by numpydoc !!