Research on Matching Mechanism between Polymer Microspheres with Different Storage Modulus and Pore Throats in the Reservoir

Polymer microsphere profile control technology has been a promising new profile control technology in heterogeneous reservoirs. The matching between polymer microsphere and pore throat of the reservoirs is crucial for profile control treatment. In this paper, the matching mechanism between polymer microsphere and pore throat had been systematically studied by sand pack models and micro models. The optical microscope and laser particle size analyzer were used to analyze the morphology and particle size of polymer microspheres before and after injection. The matching factor was proposed to evaluate the compatibility. The long sand pack model was used to evaluate the migration rule of polymer microspheres. Three modes including the migration mode, blockage mode and seepage mode were concluded and five passing through patterns, which were deformable passing through, partition passing through, blockage, adhesion and direct passing through, were observed. The specific corresponding statistical data of matching factors and passing through patterns in different storage modulus was established. The long sand pack displacement experiment showed that polymer microspheres could migrate into the deep reservoir. The comprehensive correlation equation pin = 3.3072 x 10− 7G′ 2.6492R2.3882G′ −0.0568 was derived according to the laboratory physical simulation data and the stable injection pressure of polymer microsphere with different storage modulus in different matching factors was predicted. This research will provide theoretical support for the further EOR research and field application of polymer microspheres profile control system