Recent fracture conductivity testing in the laboratory has achieved a new degree of realistic simulation of reservoir fracture conditions. Many investigators are now attempting to develop more accurate testing procedures. At least two laboratories have published data where conductivity tests have simultaneously included the effects of gel filter cakes, formation core effects, and extended test times at representative reservoir stress and temperatures. In this paper, work published in 1986 and 1987 is reviewed, and additional conductivity data with gel filter cakes are presented. Data showing the result of varying the proppant concentration inside the fracture from 0.75 up to 2.8 lb/ft2 are presented for the first time, showing that the effect of proppant concentration can not be neglected.
The economic success of hydraulic fracturing treatments depend on obtaining sufficient fracture conductivity within the proppant bed. This is illustrated by using a fracture design simulator to model the resultant propped fracture geometry and proppant distribution. By incorporating laboratory measured conductivity values (where gel filter cakes are present) these simulations show the importance of having realistic conductivity data when trying to optimize the treatment design.