CN103880359B - Silica alumina composite ceramics microballon prepares oil well cementing cement briquette method - Google Patents

Abstract

The invention provides silica alumina composite ceramics microballon and prepare oil well cementing cement briquette method, comprise the preparation of silica alumina composite ceramics closed pore cenosphere, batching, mixing, stirring is sized mixing, die trial, strength trial, by G level oil well cement 40 ~ 50wt%, particle diameter 13 μm of superfine cement 10 ~ 15wt%, particle diameter is the composite ceramics closed pore cenosphere 25 ~ 35wt% of 5 ~ 50 μm, flyash 5 ~ the 7wt% of loss on ignition 1.1%, purity 99.9% calcium oxide 1.5 ~ 2wt%, sodium sulfate 0.5 ~ 1.0wt% and SILICA FUME 1 ~ 3wt% mixing and stirring, with 0.5 ~ 0.6(W/C) water cement ratio stir in stirrer and size mixing 40 seconds, pour die trial into, maintenance 24 hours in the water-bath maintaining box of constant temperature 52 DEG C, 48 hours, soak 1 hour in cold water after the demoulding, carry out performance test.

Description

Method for preparing oil well cementing cement test block with silica-alumina composite ceramic microbeads

technical field

The invention relates to a method for preparing an oil well cementing cement test block with silica-alumina composite ceramic microbeads, and belongs to the field of material technology.

Background technique

At present, the domestic oil well cementing lightening agent uses floating beads in fly ash, including sinking beads and floating beads in fly ash, and the density of sinking beads is between 1.1 and 2.8g/cm ³ 70%, floating beads are glass beads in fly ash that are less dense than water. The floating beads mainly include aluminosilicate glass beads and porous carbon particles. After removing the carbon particles, the floating beads mainly include thin-walled aluminosilicate glass beads. Smooth surface, large volume, is a round, light weight, closed-cell hollow, wear-resistant, high temperature resistance, small thermal conductivity, high strength, the amount of floating beads accounts for 0.5 to 1% of the total fly ash, aluminum silicon Glass beads are hollow spherical spheres.

Among them, the floating beads in the fly ash are when the pulverized coal is burned at 1100-1500°C in the boiler of the thermal power plant, the clay substance melts into micro-droplets, and spins at a high speed under the action of the turbulent hot air in the furnace to form round silicon particles. Aluminum spheres, gases such as nitrogen, hydrogen and carbon dioxide produced by combustion and cracking reactions, expand rapidly in the molten high-temperature aluminum-silicon spheres, and form hollow glass bubbles under the action of surface tension, and then enter the flue to cool rapidly and harden , become high-vacuum glassy hollow microspheres, that is, fly ash floating beads.

Put the fly ash into the water and stir it, let it stand for a period of time, because the density of the floating beads is less than that of the water, take out the floating beads on the water surface and dry them, that is, the floating beads. The floating beads in the fly ash are off-white, and the main components are SiO ₂ accounts for 70% and AI ₂ O ₃ accounts for 13%, the loss on ignition is 0.40%~0.574%, the density is 0.475~0.574g/cm ³ , the wall thickness is 1.44~5.41μm, and the particle size range is mainly distributed in 147~84μm. However, the particle size of floating beads is large and the compressive strength is low.

In recent years, due to the influence of smoggy weather in the north, my country's large and medium-sized thermal power plants have adopted environmentally friendly desulfurization technology, and the fly ash does not contain floating beads, resulting in tight supply. Only small and medium thermal power plants and small boilers have not adopted desulfurization technology. Supply a small amount of floating beads, the shortage of floating beads causes the price to rise, and the floating beads are impure and mixed with fly ash, which affects the quality of cementing. The price of floating beads is at least 10,000 yuan per ton, and the maximum compressive strength is 20MPa, so it is used Composite ceramic materials make hollow microspheres instead of fly ash floating beads, which are not restricted by environmental conditions, have great economic benefits, and have good market prospects.

In the field of oil field cementing, oil and gas layers are widely distributed, and there are more and more long-sealed wells. The long-sealed wells are mainly cemented with low-density cement, and the long-sealed wells are mainly used for low-density cement slurry. If the density of the cement slurry is 1.0g /cm ³ ～1.5g/cm ³ , the density of non-floating bead lightening materials (composed of inorganic mineral materials and organic synthetic materials) must be between 0.5g/cm ³ ～0.8g/cm ³ in order to prepare low density The cement slurry (G grade oil well watertight density is 3.1g/cm ³ , the density of the lightening agent must be less than 1g/cm ³ , in order to prepare cement slurry with a density between 1.0g/cm ³ and 1.5g/cm ³ , the prerequisite is The amount of lightening agent added should not exceed 40% of the total, otherwise it will affect the compressive strength of the cement test block).

According to different cementing depths, oil wells below 2,000 meters are usually called low-temperature wells, and low-temperature oil wells are cemented with high-density cement slurry (the temperature in the oil well is between 70 and 90°C, that is, the cement slurry density is 1.8g/cm ³ ～1.9g/cm ³ ); between 2000 and 4000 meters is called medium temperature well, medium temperature oil well cementing with medium density cement slurry (the temperature in the oil well is between 90～150℃, that is, the cement slurry density is 1.6g/cm3 cm ³ ～1.7g/cm ³ ); while those with a depth of more than 4,000 meters are high-temperature wells, high-temperature oil wells are cemented with low-density cement slurry (the temperature in the oil well is between 150 and 240°C, that is, the cement slurry density is 1.0 g/cm 3 ). cm ³ ~1.5g/cm ³ ).

Due to the gradual reduction of oil and gas resources in low-temperature oil wells on land, the development of low-temperature oil wells on land has gradually shifted from low-temperature oil wells on land to deep land and ocean deep layers. The traditional cementing material floating beads cannot meet the needs of deep high-temperature oil wells. Meet the requirements of deep high pressure and high temperature oil wells..

Silica-alumina composite ceramic materials are used to prepare closed-cell hollow microspheres, which are sintered at high temperature to form a silicon-aluminum composite. The silica content is as high as 70%, and it has the property of not deforming or cracking under long-term high temperature conditions.

Contents of the invention

The purpose of the present invention is to overcome the current situation of the existing fly ash floating beads technology, replace the fly ash floating beads with composite ceramic hollow microspheres, provide a low cost, excellent performance, so that the density change rate of the cement test block is less than 0.02, To achieve the cementing design density, the closed-cell hollow microspheres are prepared with silica-alumina composite ceramic materials. After high-temperature sintering, the performance indicators such as compressive strength and flexural strength exceed those of fly ash floating beads, and the production is not affected by other conditions. , the density range of composite ceramic closed-cell hollow microspheres is controllable from 0.5g/cm ³ to 0.8g/cm ³ , and then the preparation method of low-density cement test blocks for oil well cementing with 1.0g/cm ³ to 1.5g/cm ³ is configured to meet the 4,000-7,000 meters deep oil well long sealing and cementing material requirements.

Its technical scheme is.

Including the preparation of silica-alumina composite ceramic closed-cell hollow microspheres, batching, mixing, stirring and slurry mixing, mold testing, and strength testing. %, 25-35wt% silica-alumina composite ceramic beads with a particle size of 5-50μm, 5-7wt% fly ash with a loss on ignition of 1.1%, 1.5-2wt% calcium oxide with a purity of 99.9%, 0.5% sodium sulfate ～1.0wt% and microsilica fume 1～3wt% are evenly mixed, and the water-cement ratio of 0.5～0.6 (W/C) is mixed in the mixer for 40 seconds, and some samples are taken for cement slurry performance test, including Silica-alumina composite ceramic closed-cell hollow microspheres are used for determination of hydrostatic pressure resistance, cement slurry density determination, compressive density test, settlement stability, free liquid precipitation, water loss reduction, thickening time, fluidity index, pouring Put into the test mold (a group of two pieces with length, width and height respectively 53mm*53mm*53mm), and cure them in a water bath curing box with a constant temperature of 52°C for 24 hours and 48 hours, and soak them in cold water for 1 hour after demolding to carry out compression resistance Performance Testing.

In the method for preparing oil well cementing cement test block with silica-alumina composite ceramic microbeads, the silica with a particle size of 1-30 μm, the alumina with a particle size of 5-50 μm, and the binder are 92-94% by weight: 1-5%: 1-3% mixed powder is stirred evenly, pressed into a press, dried and molded, fired at 600-800°C for 8-12 hours, kept and sintered at 1000-1350°C in a vacuum furnace for 12 hours, and the carbon dioxide The silicon oxide sintered body is processed into microbeads of 10-50 μm in the spheroidizing machine.

In the method for preparing oil well cementing cement test block with silica-alumina composite ceramic microbeads, the weight percentage of the silica-alumina composite ceramic microbead slurry is composed of: 10-50 μm silica-alumina composite ceramic microbeads 70-80wt%: 20-30wt% water.

In the method for preparing oil well cementing cement test block with silica-alumina composite ceramic microbeads, the foaming agent is added to the slurry of silica-alumina composite ceramic microbeads, which is light calcium carbonate, potassium sulfate or sodium sulfate A kind of, the concentration used is 1～3g/L.

The method for preparing the oil well cementing cement test block with silica-alumina composite ceramic microbeads comprises fully stirring and filtering the slurry of silica-alumina composite ceramic microbeads, and adopting a high-pressure jet high-speed centrifugal rotary spraying method to form microspheres, In the four-zone electric furnace, the dehydration expansion temperature is 800-850°C, the drying and sintering temperature is 1400-1600°C, the surface melting temperature is 1700-1800°C, and the ball forming temperature is 1400-1500°C. After classification, 10-50μm silica alumina is obtained. Composite ceramic closed-cell hollow microspheres.

In the method for preparing an oil well cementing cement test block with silica-alumina composite ceramic microspheres, the floating rate of silica-alumina composite ceramic closed-pore hollow microspheres is greater than 95%.

According to the method for preparing oil well cementing cement test block by silica-alumina composite ceramic microbeads, the 8-hour compressive strength of the prepared cement test block is greater than 15MPa, and the 24-hour compressive strength is greater than 20MPa.

According to the method for preparing oil well cementing cement test blocks with silica-alumina composite ceramic microbeads, the water loss reduction of cement stones is less than 50ml/30min.

According to the method for preparing oil well cementing cement test block with silica-alumina composite ceramic microbeads, the density change rate of the cement test block is less than 0.02.

In the method for preparing oil well cementing cement test block with silica-alumina composite ceramic microbeads, the hydrostatic pressure resistance of silica-alumina composite ceramic closed-cell hollow microspheres is 60-100 MPa.

The present invention has the following advantages.

1. It can change the dependence on floating beads in fly ash in long-term cementing, and use composite ceramic materials to make lightening materials required for oil well cementing. The production process of ceramic microbeads such as density, wall thickness, and sintering temperature can be controlled.

2. The technology has advanced technology, mature technology, stable product performance, low production cost, high output and good performance, opening up a new way to synthesize new cementing materials.

3. The density of silica-alumina composite ceramic microbeads can be controlled at 0.5g/cm ³ ~0.8g/cm ³ , adding 13μm ultra-fine cement can increase the early strength of the cement stone test block, and adding micro-silica powder for filling according to the packing theory The gap between the particles increases the silica content and the suspension stability of the cement slurry. The high temperature resistance of the cement stone. The G-grade oil well cement, ultra-fine cement, and ceramic microbeads have high activity after sintering at a high temperature above 1000 ° C. The hydration reaction Fast, gel-forming, improves early strength.

4. Using a vertical four-zone high-temperature beading furnace, high-pressure spraying and high-speed centrifugal rotary spraying method is adopted. The aperture of the spray sheet determines the size of the particles. The temperature is related to the concentration of the foaming agent, and then sintered, melted, and finally formed into a ball. In order to increase the output and prevent the wall from forming, a thermal cycle exhaust system is adopted, and the fan adopts a frequency conversion speed regulating fan.

5. Due to the small particle size of silica-alumina composite ceramic microbeads, it has a strong affinity with cement slurry and strong stability of cement slurry.

6. Spheroidization technology is that the material is blown up by the fan, and the material moves and rubs against each other to form round or nearly round particles.

Detailed ways.

Example 1.

(1) Preparation of silica-alumina composite ceramic closed-cell hollow microspheres ① Batching and firing: silica with a particle size of 1-10 μm, alumina with a particle size of 5-20 μm and a binder at 92wt%: 5wt%: 3wt% mixed powder is stirred evenly, compacted in a press, dried and molded, fired at 600°C for 10 hours, kept and sintered in a vacuum furnace at 1150°C for 12 hours, and the silica alumina sintered body is processed in a spheroidizer into 10~ 20 μm microbeads, ② liquid preparation: 10 ~ 20 μm silica alumina composite ceramic microbeads 75wt%: water 25wt%, add light calcium carbonate foaming agent to the slurry, the concentration is 1g/L, ③ filter: put Large particles and impurities are removed, ④ Firing: high-pressure jet high-speed centrifugal rotary spray method is used to form microspheres, which are dehydrated and expanded on a vertical four-zone electric furnace, dried and sintered, surface melted, and formed into balls, and dehydrated on a four-zone electric furnace The expansion temperature is 800°C, the drying and sintering temperature is 1400°C, the surface melting is 1700°C, and the ball forming temperature is 1400°C. After wind cleaning and grading, 5-15μm silica-alumina composite ceramic closed-cell hollow microspheres are obtained.

(2) Take 50g of 5-15μm silica-alumina composite ceramic closed-cell hollow ceramic microbeads, put them into a beaker filled with water, stir with a glass rod for 1 minute, let stand for 5 minutes, and observe the silica-alumina composite. The suspension state of ceramic closed-cell hollow microspheres in a beaker, the floating beads and sinking beads in the beaker were taken out, dried and weighed, and the floating rate was calculated.

(3) Take 100g of composite ceramic closed-pore hollow micro-beads with a thickness of 5-15 μm and put them into a hydrostatic pressure gauge. Water enters the pressure chamber from a hydraulic pump through a capillary pressure tube, and the breakage rate of floating beads increases with the increase of hydrostatic pressure. When the test is over, take out the pressure chamber, pour the sample of composite floating beads into a beaker filled with water, float the intact floating beads in the beaker, and the broken floating beads sink to the bottom of the beaker , Take out the floating beads and sinking beads in the beaker, dry them and weigh them, and calculate the broken rate and static pressure resistance, which can be repeated 2 to 3 times.

(4) Use a laser particle size analyzer to analyze the particle size distribution of 5-15 μm silica-alumina composite ceramic closed-cell hollow microspheres, and classify the silica-alumina composite ceramic closed-cell hollow microspheres obtained by wind cleaning. Weigh 50 g and pour Add 100g of water into the beaker, stir with a glass rod, pour into the test tank of the laser particle size analyzer, observe and record the particle size distribution of the sample.

(5) Low-density oil well cementing cement test block ingredients: 40wt% of G-grade oil well cement, 15wt% of 13μm ultra-fine cement, 35wt% of silica-alumina composite ceramic closed-cell hollow microspheres with a particle size of 5-15μm, 5wt% fly ash with a loss on ignition of 1.1%, 1.5wt% calcium oxide with a purity of 99.9%, 0.5wt% sodium sulfate and 3wt% silica fume.

(6) Mixing: Take 40wt% of G-grade oil well cement, 15wt% of 13μm superfine cement, 35wt% of silica-alumina composite ceramic closed-cell hollow microspheres with a particle size of 5-15μm, and pulverized coal with a loss on ignition of 1.1% Ash 5wt%, purity 99.9% calcium oxide 1.5wt%, sodium sulfate 0.5wt% and microsilica fume 3wt% were put into a mixer and mixed evenly.

(7) Take a small amount of uniformly mixed sample in (6), pour it into a beaker, prepare cement slurry at a water-cement ratio of 0.5 (W/C), stir it evenly with a glass rod, and pour it into a mud hydrometer to measure the density.

(8) At a temperature of 28°C±1°C, pour it into a corrugated mixer with a water-cement ratio of 0.5 (W/C), mix it all within 20 seconds at a uniform low speed, then cover the lid of the mixer, and continue Stir for 40 seconds at a speed of 4000r/min, and stand for 5 minutes to observe the uniformity of the cement slurry.

(9) Pour the well-mixed cement slurry into a set of two test molds. The specifications of the test mold are 53mm in length, 53mm in width and 53mm in height.

(10) Observe, weigh and record the amount of free liquid precipitation, reduced water loss, thickening time, and fluidity indicators.

(11) Curing in a water bath curing box at a constant temperature of 52°C for 24 hours, soaking in cold water for 1 hour after demoulding, and performing compressive strength and flexural strength tests and density change rate tests according to the provisions of the national standard GB/T 177.

(12) Curing in a water bath curing box at a constant temperature of 52°C for 48 hours, soaking in cold water for 1 hour after demoulding, and performing compressive strength and flexural strength tests and density change rate tests according to the provisions of the national standard GB/T 177.

Example 2.

(1) Preparation of silica-alumina composite ceramic closed-cell hollow microspheres ① Batching and firing: silica with a particle size of 10-20 μm, alumina with a particle size of 20-35 μm and a binder at 95wt%: 3wt%: 2wt% mixed powder is stirred evenly, briquetted in a press, dried and formed, fired at 700°C for 10 hours, kept and sintered in a vacuum furnace at 1250°C for 12 hours, and the silica alumina sintered body is processed in a spheroidizer into 20~ 30 μm microspheres, ② Liquid preparation: 20-30 μm silica-alumina composite ceramic microbeads 72wt%: water 28wt%, add light potassium sulfate foaming agent to the slurry, the concentration is 2g/L, ③ Filtration: put Large particles and impurities are removed, ④ Firing: high-pressure jet high-speed centrifugal rotary spray method is used to form microspheres, which are dehydrated and expanded on a vertical four-zone electric furnace, dried and sintered, surface melted, and formed into balls, and dehydrated on a four-zone electric furnace The expansion temperature is 820 °C, the drying and sintering temperature is 1500 °C, the surface melting temperature is 1750 °C, and the ball forming temperature is 1450 °C. After wind cleaning and classification, 20-30 μm silica-alumina composite ceramic closed-cell hollow microspheres are obtained.

(2) Take 50g of closed-pore hollow microspheres of 20-30μm silica-alumina composite ceramics, put them into a beaker filled with water, stir with a glass rod for 1 minute, let stand for 5 minutes, and observe the silica-alumina composite ceramics For the suspended state of closed-cell hollow microspheres in a beaker, take out the floating beads and sinking beads in the beaker, dry them and weigh them, and calculate the floating rate.

(3) Take 100g of 20-30μm silica-alumina composite ceramic closed-pore hollow microspheres and put them into the hydrostatic pressure instrument. The water enters the pressure chamber from the hydraulic pump through the capillary pressure tube. When the pressure increases, write down the hydrostatic pressure value. After the test is over, take out the pressure chamber, pour the sample of floating beads into a beaker filled with water, float the intact floating beads in the beaker, and sink the broken floating beads. At the bottom of the beaker, take out the floating beads and sinking beads in the beaker, dry them and weigh them, and calculate the breakage rate and static pressure resistance, which can be repeated 2 to 3 times.

(4) Use a laser particle size analyzer to analyze the particle size distribution of 20-30 μm silica-alumina composite closed-cell hollow ceramic microbeads, and classify the silica-alumina composite ceramic closed-cell hollow microspheres obtained by wind cleaning. Weigh 50 g and pour Add 100g of water into the beaker, stir with a glass rod, pour into the test tank of the laser particle size analyzer, observe and record the particle size distribution of the sample.

(5) Low-density oil well cementing cement test block ingredients: 45wt% of G-grade oil well cement, 15wt% of 13μm ultra-fine cement, 30wt% of silica-alumina composite ceramic closed-cell hollow microspheres with a particle size of 20-30μm, 6wt% fly ash with a loss on ignition of 1.1%, 2wt% calcium oxide with a purity of 99.9%, 1wt% sodium sulfate and 1wt% silica fume.

(6) Mixing: Take 45wt% of G-grade oil well cement, 15wt% of 13μm ultra-fine cement, 30wt% of silica-alumina composite ceramic closed-cell hollow microspheres with a particle size of 20-30μm, and pulverized coal with an ignition loss of 1.1% 6wt% ash, 2wt% calcium oxide with a purity of 99.9%, 1wt% sodium sulfate and 1wt% silica fume were put into a mixer and mixed evenly.

(7) Take a small amount of uniformly mixed sample in (6), pour it into a beaker, prepare cement slurry with a water-cement ratio of 0.6, stir it evenly with a glass rod, and pour it into a mud hydrometer to measure the density.

(8) At a temperature of 28°C±1°C, pour it into a corrugated mixer with a water-cement ratio of 0.6 (W/C), mix it all within 20 seconds at a uniform low speed, then cover the lid of the mixer, and continue Stir for 40 seconds at a speed of 4000r/min, and stand for 5 minutes to observe the uniformity of the cement slurry.

(9) Pour the well-mixed cement slurry into a set of two test molds. The specifications of the test mold are 53mm in length, 53mm in width and 53mm in height.

(10) Observe and record the amount of free liquid precipitation, water loss reduction, thickening time, and fluidity indicators.

(11) Curing in a water bath curing box at a constant temperature of 52°C for 24 hours, soaking in cold water for 1 hour after demoulding, and performing compressive strength and flexural strength tests and density change rate tests according to the provisions of the national standard GB/T 177.

(12) Curing in a water bath curing box at a constant temperature of 52°C for 48 hours, soaking in cold water for 1 hour after demoulding, and performing compressive strength and flexural strength tests and density change rate tests according to the provisions of the national standard GB/T 177.

Example 3.

(1) Preparation of silica-alumina composite ceramic closed-cell hollow microspheres ①Batching and firing: Silica with a particle size of 20-30 μm, alumina with a particle size of 35-50 μm and a binder according to 94wt%: 5wt%: 1wt% mixed powder is stirred evenly, compacted in a press, dried and formed, fired at 800°C for 10 hours, kept and sintered in a vacuum furnace at 1350°C for 12 hours, and the silica alumina sintered body is processed in a spheroidizer into 40~ 50μm microbeads, ② Liquid preparation: 40-50μm silica-alumina composite ceramic microbeads according to 80wt%: water 20wt%, add light sodium sulfate foaming agent to the slurry, the concentration is 3g/L, ③filter: Remove large particles and impurities, ④ Firing: Use high-pressure jet high-speed centrifugal rotary spray method to form microspheres, dehydrate and expand on a vertical four-zone electric furnace, dry and sinter, surface melt, and form balls, and pass through four-zone electric furnace The dehydration expansion is 850°C, the drying and sintering temperature is 1600°C, the surface melting temperature is 1800°C, and the ball forming temperature is 1500°C. After wind cleaning and classification, 35-50 μm silica-alumina composite ceramic closed-cell hollow microspheres are obtained.

(2) Take 50g of closed-pore hollow microspheres of 35-50μm silica-alumina composite ceramics, put them into a beaker filled with water, stir with a glass rod for 1 minute, let stand for 5 minutes, and observe the silica-alumina composite ceramics For the suspended state of closed-cell hollow microspheres in a beaker, take out the floating beads and sinking beads in the beaker, dry them and weigh them, and calculate the floating rate.

(3) Take 100g of 35-50μm silica-alumina composite ceramic closed-pore hollow microspheres and put them into the hydrostatic pressure instrument. The water enters the pressure chamber from the hydraulic pump through the capillary pressure tube. When the pressure increases, write down the hydrostatic pressure value. After the test is over, take out the pressure chamber, pour the sample of floating beads into a beaker filled with water, float the intact floating beads in the beaker, and sink the broken floating beads. At the bottom of the beaker, the floating beads and sinking beads in the beaker were taken out, dried and weighed, and the broken rate and static pressure resistance were calculated.

(4) Analyze the particle size distribution of 35-50 μm silica-alumina composite ceramic closed-cell hollow microspheres with a laser particle size analyzer, and classify the silica-alumina composite ceramic closed-cell hollow microspheres obtained by wind cleaning and classification, weighing 50g into the Add 100g of water to the beaker, stir it with a glass rod, pour it into the test tank of the laser particle size analyzer, observe and record the particle size distribution of the sample.

(5) Low-density oil well cementing cement test block ingredients: 45wt% of G-grade oil well cement, 12wt% of 13μm ultra-fine cement, and 33wt% of silica-alumina composite ceramic closed-cell hollow microspheres with a particle size of 35-50μm , 7wt% fly ash with 1.1% loss on ignition, 1.5wt% calcium oxide with a purity of 99.9%, 0.5wt% sodium sulfate and 1wt% silica fume.

(6) Mixing: Take 45wt% of G-grade oil well cement, 12wt% of 13μm ultra-fine cement, 33wt% of silica-alumina composite ceramic closed-cell hollow microspheres with a particle size of 35-50μm, and pulverized coal with an ignition loss of 1.1% 7wt% of ash, 1.5wt% of calcium oxide with a purity of 99.9%, 0.5wt% of sodium sulfate and 1wt% of silica fume were put into a mixer and mixed evenly.

(7) Take a small amount of uniformly mixed sample in (6), pour it into a beaker, prepare cement slurry at a water-cement ratio of 0.55 (W/C), stir it evenly with a glass rod, and pour it into a mud hydrometer to measure the density.

(8) At a temperature of 28°C±1°C, pour it into a corrugated mixer with a water-cement ratio of 0.55 (W/C), mix it all within 20 seconds at a uniform low speed, then cover the lid of the mixer, and continue Stir for 40 seconds at a speed of 4000r/min, and stand for 5 minutes to observe the uniformity of the cement slurry.

(9) Pour the well-mixed cement slurry into a set of two test molds. The specifications of the test mold are 53mm in length, 53mm in width and 53mm in height.

(10) Observe and record the amount of free liquid precipitation, water loss reduction, thickening time, and fluidity indicators.

(11) Curing in a water bath curing box at a constant temperature of 52°C for 24 hours, soaking in cold water for 1 hour after demoulding, and performing compressive strength and flexural strength tests and density change rate tests according to the provisions of the national standard GB/T 177.

(12) Curing in a water bath curing box at a constant temperature of 52°C for 48 hours, soaking in cold water for 1 hour after demoulding, and performing compressive strength and flexural strength tests and density change rate tests according to the provisions of the national standard GB/T 177.

Note: Grade G oil well cement is Shandong Qiyin Cement Factory, Shandong Zibo Xinya Calcium Industry with a purity of 99.9%, and fly ash Huaneng Xindian Power Plant with a loss on ignition of 1.1%.

Claims (6)

1. silica alumina composite ceramics microballon prepares oil well cementing cement briquette method, comprise the preparation of silica alumina composite ceramics closed pore cenosphere, batching, mixing, stirring is sized mixing, die trial, strength trial, it is characterized in that: by particle diameter 1 ~ 30 μm of silicon-dioxide, particle diameter 5 ~ 50 μm of aluminum oxide and binding agent stir by weight 92 ~ 94wt%:1 ~ 5wt%:1 ~ 3wt% mixed powder, above constituent mass per-cent sum is 100%, at pressing machine briquetting, drying and moulding, burn 8 ~ 12 hours at 600 ~ 800 DEG C, 1000 ~ 1350 DEG C of heat preservation sinterings 12 hours in a vacuum furnace, silicon-dioxide oxidation and sinter body is processed into 10 ~ 50 μm of microballons at balling machine, the weight percent of silica alumina composite ceramics microballon liquid slurry consists of 10 ~ 50 μm of silica alumina composite ceramics microballons 70 ~ 80wt%: water 20 ~ 30wt%, in silica alumina composite ceramics microballon liquid slurry, add whipping agent is one in light calcium carbonate, potassium sulfate or sodium sulfate, and the concentration of use is 1 ~ 3g/L, silica alumina composite ceramics microballon liquid is starched abundant agitation and filtration, adopt high pressure spraying high speed centrifugation rotary spraying technique, form microballoon, expansion temperature that four district's electric furnaces dewater 800 ~ 850 DEG C, dry sintering temperature 1400 ~ 1600 DEG C, melt surface temperature 1700 ~ 1800 DEG C, become bulb temperature 1400 ~ 1500 DEG C, obtain 10 ~ 50 μm of silica alumina composite ceramics closed pore cenospheres through classification, by G level oil well cement 40 ~ 50wt%, particle diameter 13 μm of superfine cement 10 ~ 15wt%, particle diameter is the silica alumina composite ceramics closed pore cenosphere 25 ~ 35wt% of 5 ~ 50 μm, flyash 5 ~ the 7wt% of loss on ignition 1.1%, purity 99.9% calcium oxide 1.5 ~ 2wt%, sodium sulfate 0.5 ~ 1.0wt% and SILICA FUME 1 ~ 3wt% mixes, water cement ratio with 0.5 ~ 0.6 stirs in stirrer sizes mixing 40 seconds, get aliquot and carry out cement slurry property test, comprise the mensuration of silica alumina composite ceramics closed pore cenosphere resistance to hydrostatic pressure intensity, cement slurry density measures, withstand voltage density test, sedimentation stability, free liquid amount of precipitation, fluid loss falls, thickening time, the liquidity scale, pour one group of two block length into, wide, height is respectively in 53mm*53mm*53mm die trial, difference maintenance 24 hours in the water-bath maintaining box of constant temperature 52 DEG C, 48 hours, soak 1 hour in cold water after the demoulding, carry out compressive property test.

2. silica alumina composite ceramics microballon according to claim 1 prepares oil well cementing cement briquette method, it is characterized in that: silica alumina composite ceramics closed pore cenosphere its floatability is greater than 95%.

3. silica alumina composite ceramics microballon according to claim 1 prepares oil well cementing cement briquette method, it is characterized in that: the cement briquette 8 hours ultimate compression strength of preparation is greater than 15MPa, and within 24 hours, ultimate compression strength is greater than 20MPa.

4. silica alumina composite ceramics microballon according to claim 1 prepares oil well cementing cement briquette method, it is characterized in that: the fluid loss that falls of cement briquette is less than 50ml/30min.

5. silica alumina composite ceramics microballon according to claim 1 prepares oil well cementing cement briquette method, it is characterized in that: cement briquette rate of change of the density is less than 0.02.

6. silica alumina composite ceramics microballon according to claim 1 prepares oil well cementing cement briquette method, it is characterized in that: silica alumina composite ceramics closed pore cenosphere resistance to hydrostatic pressure intensity 60 ~ 100MPa.