Novel Approach in Deploying Filter Cake Breaker Post Open Hole Gravel Pack with Non-Aqueous Gravel Pack Carrier Fluid in Reservoir with Reactive Shales

Non-aqueous gravel pack carrier fluids (GPCF) have been introduced into the industry to eliminate the risks associated with the water-based carrier fluids in the presence of reactive shale interbeds in the reservoir. However, non-aqueous GPCF pose a significant barrier to the effective deployment of post-gravel pack filter cake breaker (FCB) application because all FCB systems are water-based. Therefore, a novel approach was developed for FCB application in non-aqueous GPCF environment to improve the efficiency of the FCB and the overall well performance. The non-aqueous GPCF was redesigned from ground up to promote the better diffusion of the FCB. This was accomplished by introducing a reversible emulsifier package into the non-aqueous GPCF design which allows the gravel to change wettability from an oil-wet state to a water-wet state when a low pH solution i.e., breaker is spotted inside the sand screens after the open hoel gravel pack (OHGP). To complement this, the FCB design was deconstructed, and the in-situ breaker component was blended with the gravel. The concept was to incorporate the in-situ breaker component into the gravel pore space which would promote better diffusion of FCB through the reversible non-aqueous GPCP. The in-situ breaker component is inert to the carrier fluid until it is activated by the temperature and water posing no threat to the stability of the carrier fluid while pumping. The innovative approach was tested in the laboratory setting using ceramic disks and return to flow method to prove the concept before conducting an elaborate return permeability testing with the reservoir core plugs for the final validation. Return to flow method indicated that the novel approach could improve the results by at least 10% compared to the baseline test with no breaker application. In the return permeability tests with reservoir core plugs, the novel approach resulted in 76% of the initial permeability whereas the baseline test was only 50%. Both the tests with ceramic disks and full-sequence formation damage tests with actual reservoir cores highlighted the benefits of the novel approach for gravel packing with non-aqueous GPCF and post-gravel pack FCB scenario. Non-aqueous GPCFs are relatively new to the industry and no record of the filter cake breaker application in such environment exists. This novel approach makes the filter cake breaker application possible in non-aqueous environment and pushes the existing boundaries of filter cake breaker chemistries.