OIL WELL CEMENT SLURRY HIGH-TEMPERATURE SUSPENSION STABILIZER PREPARED FROM OIL-BASED SHALE DRILLING CUTTINGS

Abstract

An oil well cement slurry high-temperature suspension stabilizer prepared from oil-based shale drilling cuttings is provided. The high-temperature suspension stabilizer is reasonable in principle, inexpensive and easily available in raw materials, high in product uniformity and good in chemical stability. Meanwhile, waste is changed into wealth. Therefore, the high-temperature suspension stabilizer is environment-friendly and has a broad industrial application prospect.

Claims

1. An oil well cement slurry high-temperature suspension stabilizer prepared from oil-based shale drilling cuttings by a method comprising the following steps: (1) performing preliminary pyrolysis on the oil-based shale drilling cuttings in a shale formation in a pyrolysis furnace under a heating program in the air atmosphere in which the temperature is raised from room temperature to 350-400 C., the heating time is 30-45 min; the temperature is preserved at 350-400 C., and the heat preservation time is 75-90 min; grinding the oil-based shale drilling cuttings after the preliminary pyrolysis and controlling a specific surface area of particle size after grinding to 200-300 m.sup.2/Kg; and (2) placing the oil-based shale drilling cuttings after preliminary pyrolysis and grinding in a corundum crucible and putting the corundum crucible in a resistance furnace, and performing heat treatment for the second time under conditions as follows: the temperature is raised from room temperature to 800 C., the heating time is 45-60 min; the temperature is preserved at 800 C., and the heat preservation time is 60-75 min; the temperature is continuously raised to 1000 C., and the heating time is 30-45 min; the temperature is preserved at 1000 C., and the heat preservation time is 60-90 min; then, cooling in a quenching and shock cooling manner, drying at 60 C. for 24 h, and grinding to obtain powder having a specific surface area of 400 m.sup.2/Kg, that is, the oil well cement slurry high-temperature suspension stabilizer is prepared.

2. The oil well cement slurry high-temperature suspension stabilizer prepared from oil-based shale drilling cuttings according to claim 1, wherein the oil-based shale drilling cuttings are drilling cuttings produced when natural gas is extracted by drilling in an oily drilling fluid environment in a shale formation.

3. The oil well cement slurry high-temperature suspension stabilizer prepared from oil-based shale drilling cuttings according to claim 2, wherein the oil-based shale drilling cuttings are taken from black shale of the Silurian Longmaxi Formation.

4. The oil well cement slurry high-temperature suspension stabilizer prepared from oil-based shale drilling cuttings according to claim 1, wherein, in the quenching and shock cooling process, water or liquid nitrogen is used as a quenching medium.

Description

DETAILED DESCRIPTION

[0020] The present invention will be further described in detail with reference to the specific embodiments.

Embodiment 1

[0021] An oil well cement slurry high-temperature suspension stabilizer is prepared from oil-based shale drilling cuttings by a method comprising the following steps: [0022] (1) 400 g of oil-based shale drilling cuttings brought back from the site are placed in a pyrolysis furnace for pyrolysis to remove most of oily hydrocarbons, wherein the temperature in the pyrolysis furnace is raised from room temperature to 400 C., the heating time is 30 min, and the heat preservation time is 90 min; at this time, no droplets are generated in a condensation device behind the pyrolysis furnace, and no ignitable gas is generated in the exhaust gas; and the drilling cuttings in the pyrolysis furnace are cooled along with the furnace. The cuttings subjected to preliminary pyrolysis are grounded, and the specific surface area of the powder after grinding is controlled to about 200 m.sup.2/Kg; [0023] (2) the pyrolysis drilling cuttings after grinding are heat treatment for the second time, and the heating and heat preservation programs are controlled strictly (the temperature is raised from room temperature to about 800 C. again, and the heating time is 45 min; the temperature is preserved at 800 C., and the heat preservation time is 75 min; the temperature is continuously raised to 1000 C., and the heating time is 30 min; the temperature is preserved at 1000 C., and the heat preservation time is 90 min). The heat-treated material after the heat preservation is immediately poured into a quenching medium for quenching treatment, and water or liquid nitrogen is used as the quenching medium during the quenching process. After the quenching is completed, the powder is placed in an oven at 60 C. and dried for 24 hours; the powder is then taken out and ground; and the specific surface area of the ground powder is controlled to be 400 m.sup.2/Kg to obtain a microparticle suspension stabilizer.

Embodiment 2

[0024] An oil well cement slurry high-temperature suspension stabilizer is prepared from oil-based shale drilling cuttings by a method comprising the following steps: [0025] (1) 600 g of oil-based shale drilling cuttings are placed in a pyrolysis furnace for pyrolytic ignition loss, wherein the temperature in the pyrolysis furnace is raised from room temperature to 400 C., the heating time is 45 min, and the heat preservation time is 75 min; at this time, no droplets are generated in a condensation device behind the pyrolysis furnace, and no ignitable gas is generated in the exhaust gas; and the drilling cuttings in the pyrolysis furnace are cooled along with the furnace. The cuttings subjected to preliminary pyrolysis are grounded, and the specific surface area of the powder after grinding is controlled to about 300 m.sup.2/Kg; [0026] (2) the pyrolysis drilling cuttings after grinding are subjected to heat treatment for the second time, and the heating and heat preservation programs are controlled strictly during the treatment process (the temperature is raised from room temperature to about 800 C. again, the heating time is 60 min; the temperature is preserved at 800 C., and the heat preservation time is 60 min; the temperature is raised to 1000 C., and the heating time is 45 min; the temperature is preserved at 1000 C., and the heat preservation time is 60 min). The heat-treated material after the heat preservation is immediately poured into a quenching medium for quenching treatment, and water or liquid nitrogen is used as the quenching medium during the quenching process. After the quenching is completed, the powder is placed in an oven at 60 C. and dried for 24 hours; the powder is then taken out and ground; and the specific surface area of the ground powder is controlled to be 400 m.sup.2/Kg to obtain a microparticle suspension stabilizer.

Embodiment 3

[0027] An oil well cement slurry high-temperature suspension stabilizer is prepared from oil-based shale drilling cuttings by a method comprising the following steps: [0028] (1) 1 kg of oil-based shale drilling cuttings brought back from the site are placed in a pyrolysis furnace for pyrolysis to remove most of oily hydrocarbons, wherein the temperature in the pyrolysis furnace is raised from room temperature to 400 C., the heating time is 45 min, and the heat preservation time is 90 min; at this time, no droplets are generated in a condensation device behind the pyrolysis furnace, and no ignitable gas is generated in the exhaust gas; the drilling cuttings in the pyrolysis furnace are cooled along with the furnace and are grounded; and the specific surface area of the powder after grinding is controlled to about 250 m.sup.2/Kg; [0029] (2) the pyrolysis drilling cuttings after grinding are placed in two crucibles respectively and subjected to heat treatment for the second time, and the heating and heat preservation programs are controlled strictly (the temperature is raised from room temperature to about 800 C. again, the heating time is 50 min; the temperature is preserved at 800 C., and the heat preservation time is 70 min; the temperature is continuously raised to 1000 C., and the heating time is 40 min; the temperature is preserved at 1000 C., and the heat preservation time is 80 min). The heat-treated material after the heat preservation is immediately poured into a quenching medium for quenching treatment, and water or liquid nitrogen is used as the quenching medium during the quenching process. After the quenching is completed, the powder is placed in an oven at 60 C. and dried for 24 hours; the powder is then taken out and ground; and the specific surface area of the ground powder is controlled to be 400 m.sup.2/Kg to obtain a microparticle suspension stabilizer.