Changes

  | part    = Predicting the occurrence of oil and gas traps

  | part    = Predicting the occurrence of oil and gas traps

  | chapter = Predicting reservoir system quality and performance

  | chapter = Predicting reservoir system quality and performance

  | frompg  = 9-1

  | frompg  = 9-36

  | topg    = 9-156

  | topg    = 9-37

  | author  = Dan J. Hartmann, Edward A. Beaumont

  | author  = Dan J. Hartmann, Edward A. Beaumont

  | link    = http://archives.datapages.com/data/specpubs/beaumont/ch09/ch09.htm

  | link    = http://archives.datapages.com/data/specpubs/beaumont/ch09/ch09.htm

==Converting lab capillary pressure data==

==Converting lab capillary pressure data==

Follow the steps in the table below to convert P_c to [[buoyancy pressure]], pore throat size (''r''), or hydrocarbon column height (''h''′). Assume water-wet conditions in the reservoir (γ = interfacial tension, Θ = contact angle).

Follow the steps in the table below to convert P_c to [[buoyancy pressure]], pore throat size (''r''), or [[hydrocarbon column]] height (''h''′). Assume water-wet conditions in the reservoir (γ = interfacial tension, Θ = contact angle).

{| class = "wikitable"

{| class = "wikitable"

| 1

| 1

| Rescale P_c from one lab system to a common technique (i.e., air–brine to air–mercury).  

| Rescale P_c from one lab system to a common technique (i.e., air–brine to air–mercury).  

| <math>P_{\text{c system1}} = P_{\text{c system2}} (\frac{\gamma \cos \Theta \text{ of system1}}{\gamma \cos \Theta \text{ of system2}})</math>

| <math>P_{\text{c system1}} = P_{\text{c system2}} \left ( \frac{\gamma \cos \Theta \text{ of system1}}{\gamma \cos \Theta \text{ of system2}} \right )</math>

|-

|-

| 2

| 2

| Convert lab P_c to reservoir P_c (i.e., air– mercury to water–oil).

| Convert lab P_c to reservoir P_c (i.e., air– mercury to water–oil).

| P_c_res = P_c_lab (γcosΘ_res /γcosΘ_lab )

| <math>P_{\text{c res}} = P_{\text{c lab}} \left ( \frac{\gamma \cos \Theta_{\text{res}}}{\gamma \cos \Theta_{\text{lab}}} \right )</math>

|-

|-

| 3

| 3

| Convert reservoir P_c to height ( ''h'' ′).

| Convert reservoir P_c to height ( ''h'' ′).

| h′ = P_c_res /(water gradient – hydrocarbon gradient) <break> </break> Typical gradients in psi/ft: Water = 0.433 – 0.45, Oil = 0.33, Gas = 0.07 (range = 0.001–0.22)

| <math>h' = \frac{P_{\text{c res}}}{(\text{water gradient } - \text{ hydrocarbon gradient})}</math><br>

Typical gradients in psi/ft:

: Water = 0.433 – 0.45,  

: Oil = 0.33,  

: Gas = 0.07 (range = 0.001–0.22)

|-

|-

| 4

| 4

| Convert lab P_c to pore throat radius ( ''r'' ) in microns.

| Convert lab P_c to pore throat radius ( ''r'' ) in microns.

| r = –2γcosΘ/P_c_lab or C(γcosΘ_lab )/P_c_lab where C is the constant 0.29

| <math>r = \frac{-2 \gamma \cos \Theta}{P_{\text{c lab}}} \text{ or } \frac{C ( \gamma \cos \Theta_{\text{lab}})}{P_\text{c lab}}</math><br>  

where C is the constant 0.29

|}

|}

[[Category:Predicting the occurrence of oil and gas traps]]  

[[Category:Predicting the occurrence of oil and gas traps]]  

[[Category:Predicting reservoir system quality and performance]]

[[Category:Predicting reservoir system quality and performance]]