Study On Impact Of Chemicals For Alkali-Surfactant-Polymer Compound Flooding On Environment In Accident Of Release

Alkali-surfactant-polymer(ASP) compound flooding is widely used in oilfields and plays a very important role in oil recovery.With the ASP flooding expanded application,alkali,surfactant,polymer and its compound in ASP is impossible avoid leaking to environment during the process of transport,preparation,storage and injection.Therefore,the widely ASP flooding application will bring the corresponding environmental problems.It is necessary to study and evaluate the pollutants environmental behaviors and impacts of ASP chemicals to provide the reliable technology guarantee for the next ASP large-scale application.In this paper,according to the existing domestic and overseas environmental standards and evaluation methods,the main environmental particular pollutants in ASP are identified as alkali(sodium hydroxide),surfactant(linear alkylbenzene sulfonates,unsulphonic oil) and polyacrylamide(acrylamide) by detecting the chemical compositions and contents of ASP chemicals,injection and flooding produced water in daqing oilfield.And the impact of main environmental particular pollutants in ASP on environment for accident of release are analyzed in detail.The alkali and unsulphonic oil in ASP can cause enormous harm to ecological environment and the harm show lasting and intractable features.The concentration of linear alkylbenzene sulfonates(LAS) is the key factor to measure its harm to the environment,when the concentration is less than a certain value,it is good to environment,but toxic enhanced with the increase of concentration.The polyacrylamide(PAM) is less environmental contamination and non-toxic to plants and animals,but its degradation product acrylamide(AM) can cause great harm to human beings and environment.Environmental behaviors of ASP chemicals in soil for accident of release is completed studied in this paper.The migration of unit pollutant(alkali,LAS,PAM)and ternary pollutants in different soils(black soil,loess soil,saline alkali soil) under natural and simulated rainfall conditions are studied by onsite sampling and soil column experiments in laboratory.Effect of time and amount on the law of pollutants transferring in soil is investigated and the vertical migration law in soil is found.Under normal circumstances,when ASP chemicals accident happened,the migration distance of alkali pollutants in soil does not exceed 15cm,migration distance of LAS not exceed 20cm,migration distance of PAM not exceed 15cm in period of time.Moreover,the adsorption and degradation of PAM and LAS on the environment are also studied in laboratory.LAS degradate fast in the environment.PAM has a high adsorptive affinity on soil and it is very difficult desorbed.Based on the comprehensive analysis of environmental behaviors of ASP pollutants in soil,we can conclude that most particular pollutants in ASP rested soil surface in the leaking accident.Even much more pollutants on soil surface under rainfall conditions,it will not affect groundwater in daqing.The study of the behavior and impact of ASP pollutants in soil will provide insight into the character of environmental behaviors,which is of great significance for improving the oil industry productivity together with eco-environmental protection and reducing environmental pollution.