The method for preparing high-temperature and high-pressure oil well cementing test blocks with niobium carbide ceramic beads includes the preparation, batching, mixing, stirring and slurry adjustment, mold testing, and performance testing of niobium carbide closed-cell hollow ceramic beads. The bead performance test includes the measurement of floating rate, density, hydrostatic pressure resistance, determination of slurry density, sedimentation stability, thickening time, water loss, pressure density test, fluidity index, pressure resistance test; here is the focus Introduce the preparation of niobium carbide closed-cell hollow ceramic beads,
It includes the following steps:
Step 1. ingredients: take the niobium pentoxide powder with a particle size of 1-10 µm and phenolic resin in a weight ratio: 1.0wt%: 0.2～0.5wt%;
Step 2. blanking: mix the niobium pentoxide powder with a particle size of 1-10 µm and phenolic resin according to the weight percentage of the first step to obtain the mixed powder, stir it evenly, and cure at 50-100°C to cure The body is pulverized in a powder mill to obtain a mixed powder with a particle size of 1-10 µm. The mixed material is placed in a mold, and a pressure of 1 to 3 MPa is applied on the press to form a blank;
Step 4.the production of niobium carbide solid beads: the third step is to crush the niobium carbide block into large particles, and process them on a spheroidizing machine to produce a particle size of 5-10μm Niobium carbide spherical solid particles;
Step 5. the preparation of niobium carbide slurry: the composition of the niobium carbide slurry by weight is: the particle size is 5-10 µm, niobium carbide 65-70 wt%: water 30-35 wt%;
Step 6. Adding foaming agent: Add foaming agent, one of calcium carbonate, potassium sulfate or sodium sulfate, to the niobium carbide slurry produced in step 5, with a concentration of 1 to 3 g/L;
Step 7. the sixth step, the mixed slurry is fully stirred and filtered, and the high-pressure jet high-speed centrifugal rotary spray method is used to form microspheres, which are expanded, high-temperature sintered, surface melted and vitrified, and balled on a zone-controlled oxygen-enriched gas furnace , After wind selection and classification, 5-50μm niobium carbide closed-cell hollow ceramic beads, niobium carbide closed-cell hollow ceramic beads have a wall thickness of 10-20µm, and a compressive strength of 120-300 MPa.
