A Case Study of ASP Multi-well Groups’ Development Characteristics in Daqing Oil Field

Abstract

Alkali-Surfactant-Polymer (ASP) pilot and enlarged field tests are all successful in Daqing Oil Field, demonstrating ASP process can greatly enhance oil recovery by 20% OOIP and bring more economic benefits. But the previous tests were all carried in one group of wells which couldn't reflect performances and adaptability of ASP industrial application. Therefore, the commercial field test in multi-well groups with homemade surfactant has been carried out to study performances, scaling characteristics and matching adjusting technologies and to accelerate industrial generalization of ASP flood. The test shows that ASP flood is suitable for the reservoir whose connecting proportion of river channel sand is above 70%, and permeability is over 0.3um2. The larger the well space is, the longer time alkali takes to transfer in reservoir, which results in serious chromatographic separation, scaling, and decrease of injecting-producing capability. Development result can be improved by fracturing on injectors and producers, ceramsite fracturing proppant being the best choice, and by low-carbon mixed organic acid on heavily scaled producers during the late development stage to remove blockage, but the influence of scale can't be totally eliminated. Due to lateral and inter-layers’ heterogeneity in the reservoir, less recovery has been achieved than in the pilot test. We can know from the test that if the well-space is shortened in industrial application, and anti-scaling method is optimized, oil recovery will be further improved.