Development and Introduction of Heavy Organic Compound Deposition Diagnostics, Prevention and Removing

Abstract

Abstract One of the major unsolved complex systems confronting the petroleum industry at present is the untimely depositions present in oil. Deposition of asphaltene, resin and paraffin at the formation bottom-hole zone refers to less controlled processes. The paper discusses a integratid approach to forecasting asphaltene, resin, paraffin precipitation in the formation bottom-hole zone, analysis of technological and economic efficiency of bottom-hole zone treatment using oil solvents carried out at the fields of Western Siberia and Volgo-Ural petroleum region. The method to evaluate the tendency of formation oil to deposit asphaltene, resin and paraffin under the conditions of a sharp change in thermo-baric conditions in the formation bottom-hole zone has been developed on the basis of physical-and-chemical properties of surface oil, namely viscosity, density, quantitative content of asphaltene and resin, refractive index, thermal effects of asphaltene flocculation with the account of geological properties of the petroleum reservoir. Correlation dependencies of oil heavy component composition upon its properties have been found. Maps of a number of fields have been built taking into account the risk of asphaltene, resin, and paraffin deposition. The developed method is used as the basis for choosing candidate-wells for bottom-zone treatment. To renew well productivity, it is considered optimal and efficient in the conditions of Western Siberia to carry out the bottom-hole zone treatment using hydrocarbon solvents. To date more than 1300 treatments have been carried out at 20 fields. The theoretical foundation for solvent selection to remove asphaltene, resin, and paraffin deposits in oil wells, pumps, storage vessels, transfer pipelines has been developed on the basis of modern concepts of structure, properties and reactivity of asphaltene and resin, as well as analysis of thermodynamic and kinetic aspects of solvents interaction with petroleum disperse systems.