Adaptability of a deep profile control agent to reservoirs: Taking the Lamadian Oilfield in Daqing as an example

Abstract

Lamadian Oilfield in Daqing is characterized by thick layers, complex facies combination, and serious interlayer heterogeneity, so influential factors of a deep profile control agent on deep profile control and oil production increase and its adaptability to reservoirs were studied using core flooding tests. The results show that the agent amount, intensity, and permeability variation coefficient (VK) of reservoir all influence the effect of oil production increase after profile modification. The larger the injected volume, the better the stimulation effect. The increment of recovery ratio showed an increase and then decrease trend when agent intensity increased. Larger VK resulted in better stimulation effect. Core flooding tests and instrument detection results show that, the profile control agent can flow in the pore only when the value of molecular group size and the medium value of pore throat radius are in the compatibility zone. Therefore, for a heterogeneous reservoir, the characteristics of high, middle, and low permeability layers and the match relations of agent molecular group size and medium value of pore throat radius of reservoir rock must be taken into consideration when designing the agent intensity and slug, so as to reduce the damage to middle and low permeable layers as much as possible. Key words: profile control agent, injected volume, intensity, permeability variation coefficient, molecular group size, stimulation effect after profile control, adaptability