Understanding Production Performance Rock Behavior By Using DifferentDiversion Techniques in Carbonate Matrix Acidizing Process

摘要

In stimulated carbonate formations,one damage mechanism is the loss of near wellbore rock compressivestrength upon matrix acidizing.Improper designed acidizing jobs may excessively soften the rock andnegatively impact the mechanical response of near wellbore rock during production.In this work,anintegrated geomechanical workflow is presented and applied to optimize acid placement and fluid diversiontreatment in a Middle East carbonate reservoir.The model consists of petrophysical characterization of the formation,coupled wellbore flow model,rock dissolution model,rock physical model,wellbore stress analysis and lastly production prediction.Themodel first simulates stimulation fluid movement within wellbore and couples it with transient flow inreservoir.The primary analysis determines the distribution of reactive fluid along the well and predictsporosity evolution across the reservoir domain upon stimulation.Then,the developed geomechanical enginesimulates the mechanical behavior (compressional or shear failure) of stimulated rock under different stressconditions during production stage.This paper introduces an integrated geomechanical workflow to stimulate matrix acidizing and describedynamic reservoir compaction and its influence on production performance,which varies significantly withthe stress condition,formation types and design strategy.In the presented case study,various diversiontechniques are analyzed,and overall production are compared to assess the stimulation efficiency byconsidering the effect of rock failure.The comparative analysis identifies an optimized diversion techniqueand design,which can minimize near wellbore rock failure and sustain production for a longer term.This model enables a reliable prediction of acidic fluid distribution and identification of key controllingparameters to maximize conductive reservoir volume and mitigate premature wormhole collapse.Depending on the diversion technique and reservoir conditions,the workflow can provide a proactivesolution to improve matrix acidizing design to enhance overall recovery.The presented case study can aidto build a customized and optimized strategy for matrix acidizing for middle east carbonate formations.