Experimental Study on Conductivity of Regional Sand and its Field Application

Hydraulic fracturing is the most commonly used stimulation method at present. The improvement effect and validity period mainly depend on the fracture conductivity. Carbo proppant is widely used worldwide for its excellent performance in increasing the conductivity of fracture support. The proppant used in the fracturing development of the Karamay oilfield in Xinjiang is also mainly Carbo proppant, but Karamay has abundant regional sand resources due to its special geographical location and geological conditions. Compared with the high cost and transportation cost of the Carbo proppant, the available regional sand becomes cheaper and reduces the development cost. According to the evaluation standard of flow conductivity of proppant in petroleum and natural gas industry, Firstly, the basic physical properties of the regional sand in Xinjiang were evaluated through the laboratory experiment system, and compared with the Carbo proppant. Secondly, the effect of sand placement concentration (8kg, 10kg, 16kg) and mesh number of proppant (30/50, 40/70) on regional sand conductivity was studied based on the conductivity evaluation system. Finally, the effect of the combination of regional sand and Carbo proppant on the conductivity was studied, under the same sand placement concentration and mesh number of proppant. The results of laboratory experiments show that the hardness and density of regional sand are higher than that of Carbo proppant, but the sphericity of regional sand is smaller than that of Carbo proppant. Under the same sand placement concentration, the regional sand conductivity of 30/50 meshes was higher than that of 40/70 meshes. As the concentration of sand placement increases, the ability of regional sand conductivity increases. The conductivity of a 1:1 mixture of regional sand and Carbo quartz is comparable to that of all Carbo quartz. According to the application examples of adjacent Wells A and B in block X of Xinjiang oilfield, the project that the ratio of regional sand to Carbo proppant is 1:1 can guarantee stable and effective flow conductivity and save fracturing cost.