Abstract
In 1993 and 1994, based on a large number of feasible studies, a pilot Alkaline-Surfactant-Polymer (ASP) field test was conducted in the west of the central area and in the central block of Xingwu area of Daqing oilfield, there being an increase of 21.4% and 25% as compared with water flooding respectively. In order to further investigate the displacement effectiveness of ASP flooding under the condition of the enlarged well spacing and groups, an extended field test was conducted in Beiyiduanxi of Daqing Oilfield on the basis of the two successful pilot field tests in 1997, further verifying the EOR magnitude of ASP flooding and the performance variation regularities from the injection-production capability and the chromatographic fractionation and technically being ready for the industrial popularization of ASP flooding. This paper focuses on the laboratory study, the formulation optimization, the numerical simulation, and the field test study in this field test, studies the performance variation regularities and features of ASP flooding by combining the geological data, the injection profile, the production profile, the detection of polymer, surfactant and alkaline concentration in the produced fluid, the analysis of various ions, and the dynamic and static data of the daily fluid production, the daily oil production and the water cut variation, and raises the solutions and the preventive measures for the emulsification and the scale formation and so on during ASP flooding, thus enhancing the ultimate recovery factor. At present, in the test area, injection according to the ASP system program has been completed, the stage of the subsequent water flooding has been entered, and the better test results has been obtained. At the peak response stage the water cut of the central wells reduced from 95.0% in water flooding to 54.4%, lowering by 40.6 percentage points, which lasted for 1 year, and the recovery factor increased by 20.49%.
An Extended field test of Alkaline-surfactant-polymer (ASP) flooding in Beiyiduanxi Area of Daqing Oilfield is a test with large well spacing, multi-well groups, and a large slug that is conducted on the basis of the laboratory study, the formulation optimization, and the numerical simulation study for acceleration of industral application. The test studies the performance variation regularities and features of the ASP flooding by combining the geological data, the injection profile, the liquid-production profile, the detection of polymer, surfactant and alkaline concentration in the produced liquid, the analysis of various ions, and the dynamic and static data of the daily liquid production, the daily oil production and the water cut variation, raises the solutions and the preventive measures for the emulsification and the scale formation and so on during ASP flooding, and the obvious responses to the incremental oil and water reduction are seen. At the peak response stage the water cut of the central wells reduced from 95.0% in water flooding to 54.4%, lowering by 40.6 percentage points; the daily oil production increased from 10t in water flooding to 68t, with the daily incremental oil production being 58t, which lasted for 1 year. At present, in the test area injection of ASP system has been completed, the stage of the subsequent water flooding has been entered, the recovery factor of ASP flooding has been 20.49% more than that of water flooding.
