One of the main concerns during the completion phase of the planned Andrew
horizontal wells was sand production. Analytical models based on inputs fro
m log details and core analyses favoured the use of perforated, cemented li
ner completions to lessen the likelihood of sand production. To further str
engthen this recommendation and to perform a risk analysis of formation fai
lure at the time of underbalance perforation and expected producing conditi
ons, laboratory experiments were conducted on three reservoir core samples
selected from two pilot wells. The core samples were perforated with shaped
charges under simulated downhole conditions. The perforated core samples w
ere flowed, while monitoring any sand production resulting from the effects
of increasing rate (change in drawdown), onset of water cut and depletion
(increasing effective stress).
The core samples did not show any propensity to produce sand during single-
phase oil flow rates of up to 20 cm(3)/s/perforation). When water cut was i
ntroduced, transient sand production was observed, indicating the productio
n of perforation-generated rock debris. As the percentage water cut was inc
reased, the sand production declined. The core samples did not show any pro
pensity for sand production during depletion testing. The wells were subseq
uently completed with perforated cemented liners with no sand control. Now,
into two years of production no sand problems have been encountered. These
experiments are presented as a means of complimenting existing sand predic
tion models in completion designs for sand prevention.