Subsurface Laboratory Methods 



301 



culate the volume of clean oil that will be produced before bottom water 

 cones into the sand face.^^ 



Research has determined that the presence of more than one fluid in 

 the formation affects the flow of the other fluids.^*^ The apparent perme- 

 ability to one particular phase of saturation in a mixture of fluids is 

 called the "effective permeability." Permeability tests using highly saline, 



Figure 127. Tabulated core data and interpretation for well B. The presence of a 

 gas cap and bottom water presented a problem in completion, particularly as 

 vertical permeability exists at both of the fluid contacts. This well was squeezed 

 three times in an attempt to shut off the gas; however, it is still producing with 

 a high gas-oil ratio. The residual-oil saturation is somewhat low for normal-ratio 

 production. 



synthetic brines apparently give results which reflect the effective perme- 

 ability of the formation.®^ 



The ratio of the effective permeability to the specific permeability is 

 termed the "relative permeability" and is usually expressed as a percentage 



^^Muskat, M., and Wykoff, R. D., Am. Inst. Min. Met. Eng. Trans., 1935. 



"' Muskat, M., Performance of Bottom-Water Drive Reservoirs: Am. Inst. Min. Met. Eng. Tech. Pub. 

 2060. Sept. 1946. 



*' Bolset, Hw G., Flow of Gas-Liquid Mixtures Through Consolidated Sand: Am. Inst. Min. Met. 

 Eng. Trans., 1940 



