Methodology of Studies for Optimum Clay Stabilizer Selection

Aiming at the problem of clay swelling existing in the development of low permeability reservoir, a series of methods are used to evaluate the interplanar crystal spacing of the calcium montmorillonite treated by variable concentrations of 5 Clay Stabilizers in 7 kinds of stability experiments, and the factors that affect the performance of clay stabilizers are analyzed comprehensively by testing the index such as the effective components and adsorptive capacity. With this process, the optimum clay stabilizer of the best compressive performance and its reasonable concentration are determined. Finally the results are examined by the laboratory fluid flowing experiments of cores. The process above forms a complete standard system for evaluation and selection of clay stabilizers at low permeability reservoirs. As a kind of Organic Polymer Quaternary Ammonium Salt of Potassium Ion, the selected clay stabilizer ST-04 has moderate adsorptive capacity under the optimum concentration; in the cases of variable concentrations, the ST-04 has excellent performance of anti-swelling and stability, and keep its damage rate low to pores of the rock.