Assessment Methodology for Treatment Fluid Efficiency in Modifying Filtration Properties of Porous Rocks

One of the main application areas for treatments modifying the filtration properties of porous rocks, besides improving the sealing of landfills, reducing water hazards in mine workings, and eliminating water permeability in geoengineering works, is hydrocarbon exploitation. Among the available solutions, chemical methods are considered most effective, using treatment fluids injected into water-bearing layers. The decision to perform a modification treatment using a particular treatment fluid must, in each case, be preceded by a laboratory simulation of its technological effectiveness. This article presents research aimed at developing a methodology for reliable evaluation of treatment fluids used to modify the filtration properties of porous rocks. In addition to standard flood tests, additional methods were applied, notably X-ray computed tomography, which enabled non-destructive visualization of gel barriers in rock pores. Microscopic analysis of thin sections also supported pore space characterization. Research conducted on sandstone samples with the Multizol treatment fluid, developed at the Oil and Gas Institute—National Research Institute, confirmed the outcomes of flood tests and Residual Resistance Factor (FRR) calculations. Integration of all the results enhanced the reliability of the effectiveness assessment, which may be crucial for optimizing performed treatments, especially under the variable geological conditions and petrophysical parameters of rocks of the near-wellbore zone.