Experimental study of the matching ability between inorganic particles plugging agent and formation pore constriction

In order to meet inorganic particle plugging agents injecting into the different radial depth of formation for plugging needs, in-depth study of the matching relations between inorganic particles and formation pore is the key work . This article examines not only the ratio (b) of the plugging agents particle size (d50) and the formation pore diameter (Dc), but also the introduction of the solid content (C) of inorganic particles plugging agent to control the match relations,which is the first time. Firstly, it determined ultra-fine cement as the plugging agent particles ,which the value of d50 = 25.1 μm, and chosen three different size range of reservoir sand as filling unconsolidated sand, converted the corresponding pore throat diameter dc and b value. Secondly, it used advection pumps stable the displacement q, injecting into the unconsolidated sand, simulated inorganic particles plugging into the sandstone formation process. By measuring the difference (b, C) combination with the corresponding injection pressure pz of the advection pump, it used the curve diagram (contain b, C, pz) represent the matching relations. Currently, the research results have been successfully applied to particle plugging agents injecting into the loose sandstone formation near the block wall, and is guiding the inorganic particle plugging agents injecting into deep pore formation of Dagang Oilfield plugging test.