No More Premature Collapse of Acid Wormholes: Extend Wells Productivity with Particulate Diversion Technique Modelling

Abstract

The main goal of matrix acidizing in carbonate reservoirs is to create wormhole and to remove the damage caused by drilling on the wellbore wall. The critical step in acidizing design is to optimize the design parameters for uniformly distributing the stimulation fluid. Non-engineered designed acidizing jobs will lead to softening the near wellbore rock and with time it will have a negative effect on the production. In this work, we present design and modelling of particulate diversion process using an integrated Geomechanical workflow for case histories from South America.

The model utilized petrophysical data of the formation, stresses near wellbore, wellbore flow, rock dissolution and physical model. The case history of 2 deviated wells from North and South America respectively were simulated with the stimulation fluid movement within wellbore and then it was coupled with transient flow. The primary analysis determines the distribution of reactive fluid along the well and predicted skin and wormhole evolution across the wellbore upon stimulation.

This work introduced an integrated engineering workflow to optimize and simulate carbonate matrix acidizing design using bio-degradable particulate diverters and demonstrate uniform stimulation with reduction in skin. In the presented case study, 2 jobs from North and South America were analyzed. The results demonstrate effectiveness of particulate diverters in reducing the wellbore damage, uniformly distributing the treatment fluid, increasing effectiveness of stimulation fluid, retarding the softening of rock and hence enhancing the production across the target zone.

This Geomechanics model for particle diversion permits a dependable prediction of stimulation fluid distribution across the reservoir section and identifies controlling parameters to maximize conductive reservoir volume (CRV), avoids premature collapse of wormhole, uniform distribution of the stimulation slurry and hence enhances production. The presented case study can assist in building a customized diversion strategy for Middle East carbonate formations.