Sensitivity Characteristics of the Ultradeep Carbonate Gas Reservoir

Abstract

AbstractReservoir sensitivity is a key factor that cannot be ignored in the development of oil and gas reservoirs, because it is directly related to formation damage and affects oil and gas production and recovery factor. Precipitation, swelling, or migration of clay particles occurs in the pore throats when the external fluid is incompatible with the reservoir minerals, thereby blocking pore throat channels and causing formation damage. Therefore, reservoir sensitivity is defined as the sensitivity degree of oil and gas reservoirs to various types of formation damage, including velocity sensitivity, water sensitivity, salinity sensitivity, alkali sensitivity and acid sensitivity. These five conventional sensitivities and stress sensitivity are the main factors causing formation damage during the exploration and exploitation. Formation damage will inevitably lead to changes in reservoir pore structure and fluid percolation characteristics, thereby indirectly affecting the production capacity and recovery factor of oil and gas reservoirs. Systematic evaluation and analysis of reservoir sensitivity characteristics are the basis for revealing reservoir damage mechanism and influencing factors. Developing appropriate reservoir protection and damage prevention measures is the key to maintaining efficient development of oil and gas reservoirs.