添加锰矿低密度高强度陶粒支撑剂的制备及作用机制研究

PREPARATION AND MECHANISMS OF LIGHT-WEIGHT HIGH-STRENGTH CERAMISITE PROPPANT WITH MANGANESE MINERAL ADDITIVE

低密度高强度支撑剂的开发与应用不仅有利于非胶化压裂液的使用,尤其对提高低渗透油气藏的开发效率有显著作用。以铝矾土为主要原料,添加5%锰矿,在1350℃下无压烧结,制备高强度低密度陶粒支撑剂,并讨论了锰矿掺量及烧成温度对支撑剂诸性能的影响。根据支撑剂的显微结构和孔结构分析发现:掺入5%锰矿有利于生成均匀分布的直径为0.2～1μm棒状莫来石,棒晶发挥纤维或晶须的强韧化作用,显著提高了支撑剂的强度,抗破碎能力达到69MPa闭合压力下破碎率为4.1%;在烧结后期,棒晶的生长速度过快未能有效排除气孔,导致大量晶粒间闭气孔生成,有效降低了支撑剂的密度(体积密度为1.78g/cm3,视密度为3.22g/cm3)。

The preparation and application of light-weight high-strength proppant make it benificial to the use of slick water, especially, to the development of low-permeability oil and gas reservoir. The light-weight high- strength proppant was prepared by adding 5wt% manganese mineral into bauxite and sintering at 1350℃ pressurelessly and the influences of the weight ratio of manganese mineral and sintering temperature on the properties of the proppant were discussed. The microstructure and pore were studied, and the results show that platelike mullite grains with the diameter of 0.2-1μm can be formed homogeneously by adding 5wt% manganese mineral, which play a remarkable role in the increment of fracture toughness, the breakage ratio is only 4.1% under 69MPa closure pressure. In addition, many intergranular closed pores were formed as a result of the grain growth which was too speedy to eliminate pores in late sinering phase, and the density of proppant reduced（bulk density was 1.78g/cm^3, apparent density was 3.22 g/cm^3）.