diff --git a/petropy/log.py b/petropy/log.py
index a714f89..1cf809d 100755
--- a/petropy/log.py
+++ b/petropy/log.py
@@ -492,7 +492,7 @@ def fluid_properties(self, top = 0, bottom = 100000, mast = 67,
         rmf = (rmft + 6.77) / (form_temp + 6.77) * rmfs
 
         rw68 = (rwt + 6.77) / (68 + 6.77) * rws
-        rmf68 = (rmft + 6.77) / (68 + 6.77) * rws
+        rmf68 = (rmft + 6.77) / (68 + 6.77) * rmfs
 
         ### weight percent total disolved solids ###
         xsaltw = 10 ** (-0.5268 * (np.log10(rw68) ) ** 3 - 1.0199 * \
@@ -1254,7 +1254,7 @@ def multimineral_model(self, top = None, bottom = None,
 
             e &= \\frac{c}{RESDEEP\_LOG}
 
-            SW &= ((d^2 + e)^2 - d)^{\\frac{2}{n}}
+            SW &= (\sqrt{d^2 + e} - d)^{\\frac{2}{n}}
 
         III. Modified Simandoux
 
@@ -2113,7 +2113,7 @@ def multimineral_model(self, top = None, bottom = None,
                 c = (1.0 - vclay) * a * self['RW'][i] / (phis ** m)
                 d = c * vclay / (2.0 * rt_clay)
                 e = c / self['RESDEEP_N'][i]
-                sw_simandoux = np.clip(((d**2 + e) ** 0.2 - d) ** \
+                sw_simandoux = np.clip(((d**2 + e) ** 0.5 - d) ** \
                                                          (2 / n), 0, 1)
 
                 ### modified Simandoux ###
@@ -2251,8 +2251,8 @@ def multimineral_model(self, top = None, bottom = None,
         ### since parameters depend on calculated values ###
 
         if buckles_parameter < 0:
-            buckles_parameter=np.mean(self['PHIE'][depth_index] * \
-                                      self['SW'][depth_index])
+            buckles_parameter=np.nanmean(self['PHIE'][depth_index] * \
+                                         self['SW'][depth_index])
 
             ir_denom = (self['PHIE'][depth_index] / \
                        (1 - self['VCLAY'][depth_index]))