Abstract
One of the main concerns during the completion phase of the planned Andrew horizontal wells was sand production. Analytical models based on inputs from log details and core analyses preferred perforated, cemented liner completions to lessen the likelihood of sand production. To further strengthen this recommendation and to perform a risk analysis of formation failure at the time of underbalance perforation and expected producing conditions, 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 were flowed, while monitoring any sand production resulting from the effects of increasing rate, 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 10 B/D/perforation). When water cut was introduced transient sand production was observed, indicating the production of perforation-generated rock debris. As the percentage water cut was increased, the sand production declined. The core samples did not show any propensity for sand production during depletion testing. The wells were subsequently 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 prediction models in completion designs for sand prevention.
