Non-floating bead low-density cement mortar

Abstract

The invention relates to a non-cenosphere light weight cement slurry, which mainly solves the problem that the cement slurry cannot keep the density thereof under a high pressure condition. The non-cenosphere light weight cement slurry is characterized by comprising the following components in portion by weight: 100 portions of cement, 116 to 321 portions of water, 52 to 136 portions of fly ash, 14 to 38 portions of silica fume, 14 to 38 portions of superfine cement, and 6 to 11 portions of early strength agent, wherein the particle diameter of the silica fume (of which the SiO2 content is more than 90 percent) is more than 0 and less than 0.5 mu m, the particle density of the silica fume and the fly ash is 2.0 grams per cubic meter, and the particle diameter of the superfine cement is more than 0 and less than 2 mu m. The light weight cement slurry forms a set of incompressible light weight cement slurry system of which the density is between 1.40 and 1.55 grams per cubic meter through preferentially selecting external additives and applying a grain composition principle, wherein the flowability and the sedimentation stability of the cement slurry are good, the set cement strength is more than 15 MPa and cannot decline at a temperature of 150 DEG C so as to satisfy the technical requirements on oil field exploration and development.

Description

Technical field: [0001] The invention relates to a cement used in the field of oil field drilling and cementing, in particular to a non-floating bead low-density cement slurry. Background technique: [0002] In the field of oilfield drilling and cementing, the oil and gas layers are widely distributed, and there are more and more long-sealed wells. One of the main methods used in long-sealing well cementing is to use low-density cement slurry for well cementing. At present, low-density cement slurry with floating beads is widely used in oil fields, but due to the existence of floating beads, the cement slurry cannot maintain its properties under high pressure conditions. Design density, as the pressure rises, the density of cement slurry increases, and the fluidity of cement slurry also deteriorates greatly, which brings unsafe factors to the cementing construction of deep wells in oil fields; and because floating beads are industrial by-products of power plants, With the ...

AI Technical Summary

Problems solved by technology

[0003] The present invention is to overcome the problem that the cement slurry in the background technology cannot maintain its design density under high pressure conditions, and provides a kind of non-floating pearl low-density cement slurry, The density of the non-floating bead low-density cement slurry is incompressible in the range of 1.40-1.55g / cm3, and the price is low, and the cementing cost is low, so as to meet the technical requirements of oilfield exploration and development

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