Laboratory study of ideal packing approach applied to high permeability sandstones

Abstract: It is difficult for conventional temporary bridging methods to seal large pore throats, which usually make the dominant contribution to permeability. The reason is that the particle size of conventional bridging agents is optimized depending on the median pore size of target formation. High-permeability sandstone reservoirs have such features as wide permeability distribution range, high porosity, argillaceous cement, and wide distribution range of pore throat sizes. The key factors of reservoir damage are invaded particles and filtrate of drilling fluids, as well as the hydrate expansion and dispersion of clay. The KPAM polymer drilling fluids are optimized, and ideal packing approach is applied to the drilling fluids, and the instrument of dynamic fluid loss test is used to evaluate return permeability. The test results indicate that the ideal packing approach can reduce the dynamic fluid loss, improve the return permeability, and reduce breakthrough pressure. Key words: high-permeability reservoirs, formation damage, ideal packing, return permeability, formation damage control