A low-density oil well cement slurry without floating beads

Abstract

The invention discloses floating-bead-free low-density oil well cement paste and belongs to the technical field of oil and gas well cementation. The cement paste is prepared from 10-30% of cementing material A, 15-50% of cementing material B, 2-48% of filling material, 1-3% of fluid loss agent, 1-4% of early strength agent and 0.5-1.5% of dispersing agent. The cementing material A is one of G-grade oil well cement, D-grade oil well cement and ordinary Portland cement. The cementing material B is superfine ordinary Portland cement. The cement paste has the advantages of being low in cost, low in density, and high in early strength, density stability and quality stability.

Description

technical field

[0001] The invention relates to a low-density oil well cement, in particular to a low-density oil well cement slurry without drift beads, which belongs to the technical field of oil and gas well cementing. Background technique

[0002] With the development of the drilling field, the underground pressure system is becoming more and more complex, and the number of special wells such as lost wells and heavy oil wells is increasing. The conventional cement slurry system can no longer meet the cementing requirements of such wells, especially in the high density and water loss. Too large, the early strength development of the system is too slow, and the thickening time is too long. In order to solve this series of special problems, people continue to develop cement slurry systems with different characteristics, such as low-density cement that meets different density requirements. system. The composition of the floating bead shell is very close to that of high alum...

Examples

Embodiment 1

[0032] A kind of floating bead-free oil well cement slurry, including the following raw materials by mass percentage: ordinary portland cement 18%, superfine portland cement 30%, fly ash 22.5%, micro silicon 22%, triethanolamine 3.8% , fluid loss reducer QS12S 2.5%, dispersant SXY 1.2%.

Embodiment 2

[0034] A kind of oil well cement slurry without drift beads, comprising the following raw materials in terms of mass percentage: 10% of G grade oil well cement, 41.5% of superfine portland cement, 24% of micro silicon, 18% of diatomite, and 4.0% of calcium chloride , fluid loss reducer QS12S 1.0%, dispersant SXY1.5%.

Embodiment 3

[0036] A kind of oil well cement slurry without bleaching beads, comprising the following raw materials by mass percentage: 15% of D grade oil well cement, 35% of superfine Portland cement, 20.5% of fly ash, 22% of bentonite, 2% of triethanolamine, chlorine Calcium 2%, fluid loss reducer G60S 3.0%, dispersant QS20S 0.5%.

[0037] The specific surface area of ​​the superfine portland cement of the present embodiment is 1200cm 2 / g.

technical field

[0001] The invention relates to a low-density oil well cement, in particular to a low-density oil well cement slurry without drift beads, which belongs to the technical field of oil and gas well cementing. Background technique

[0002] With the development of the drilling field, the underground pressure system is becoming more and more complex, and the number of special wells such as lost wells and heavy oil wells is increasing. The conventional cement slurry system can no longer meet the cementing requirements of such wells, especially in the high density and water loss. Too large, the early strength development of the system is too slow, and the thickening time is too long. In order to solve this series of special problems, people continue to develop cement slurry systems with different characteristics, such as low-density cement that meets different density requirements. system. The composition of the floating bead shell is very close to that of high alum...

Examples

Embodiment 1

[0032] A kind of floating bead-free oil well cement slurry, including the following raw materials by mass percentage: ordinary portland cement 18%, superfine portland cement 30%, fly ash 22.5%, micro silicon 22%, triethanolamine 3.8% , fluid loss reducer QS12S 2.5%, dispersant SXY 1.2%.

Embodiment 2

[0034] A kind of oil well cement slurry without drift beads, comprising the following raw materials in terms of mass percentage: 10% of G grade oil well cement, 41.5% of superfine portland cement, 24% of micro silicon, 18% of diatomite, and 4.0% of calcium chloride , fluid loss reducer QS12S 1.0%, dispersant SXY1.5%.

Embodiment 3

[0036] A kind of oil well cement slurry without bleaching beads, comprising the following raw materials by mass percentage: 15% of D grade oil well cement, 35% of superfine Portland cement, 20.5% of fly ash, 22% of bentonite, 2% of triethanolamine, chlorine Calcium 2%, fluid loss reducer G60S 3.0%, dispersant QS20S 0.5%.

[0037] The specific surface area of ​​the superfine portland cement of the present embodiment is 1200cm 2 / g.

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