Device and method for preparing nitrogen foam cement

Abstract

The invention discloses a device and method for preparing nitrogen foam cement. The preparing device comprises a foam cement producer, a liquid nitrogen evaporator, a liquid nitrogen plunger pump, a foam liquid plunger pump, a foam liquid tank, a heat exchange system, a liquid nitrogen pipeline, a high-pressure cement paste pipeline, a first pipeline, a foam cement discharge pipeline and a densitydetecting device. The heat generated by a power unit, a hydraulic system and other devices in a nitrogen foam well fixing device is recovered through the heat exchange system, the recovered heat is used as a heat source of the liquid nitrogen evaporator, energy conservation and environment protection are realized, the energy utilization rate is high, and equipment input is low. Liquid nitrogen and foam liquid are pressurized through a high-pressure liquid nitrogen plunger pump and a high-pressure foam liquid plunger pump, the mixing uniformity is increased, and the density of foam cement is reduced. The density of the foam cement is detected in real time through the density detecting device, the flow of the liquid nitrogen and/or foam liquid is adjusted according to the density, and the density is simply controlled. By arranging a clear water tank, after operation ends, the equipment and pipelines are flushed, and the service life is polonged.

Description

technical field [0001] The invention relates to the technical field of oil field cementing, in particular to a nitrogen foam cement preparation device and a preparation method thereof. Background technique [0002] In oil and gas field cementing operations, cement loss is one of the most common problems in the field of cementing. With the deepening of domestic oil and gas exploration and development, the proportion of cement leakage has increased sharply, seriously affecting the quality of cementing and increasing the risk of annular pressure. Compared with conventional cement, foamed cement slurry has the characteristics of low density, high strength, and good elastic-plasticity, and has significant advantages in preventing leakage, preventing channeling, and improving displacement efficiency. At present, the physical foaming method is often used to prepare foamed cement, that is, to form foamed cement by mixing the foam liquid prepared in advance with the cement slurry or...

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Problems solved by technology

At present, the existing air-filled foam cement preparation device cannot monitor the density of the foam cement in real time. If the density of the foam cement cannot meet the construction requirements, the cementing cost will increase or even the cementing will fail; and this method needs to set up a special heating device. Liquid nitrogen is used to heat up the temperature, which requires high energy consumption, high equipment investment and high operating costs

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