Horizontal well-cementation expandable cement mortar and preparation method thereof

Abstract

The invention discloses horizontal well-cementation expandable cement mortar and a preparation method thereof, and belongs to the technical field of oil and gas well cementation cement. The horizontal well-cementation expandable cement mortar comprises 100 parts of cement, 30-45 parts of a high-temperature stabilizing agent, 1-10 parts of a high-temperature expanding agent, 0-3 parts of a suspending agent, 4-10 parts of a filtrate-loss reducer, 0-2 parts of a dispersant, 0-5 parts of a retarder, 40-50 parts of water and 0.2 parts of an antifoaming agent. The cement is oil well G-grade cement satisfying the API standard. The high temperature stabilizing agent comprises one or two of micro-silicon and silica powder having purity greater than 98%. Indoor research and test prove that the horizontal well-cementation expandable cement mortar has excellent integrated performances. The cement stone prepared from the horizontal well-cementation expandable cement mortar has good settlement stability and slight expansion characteristics at a high temperature. The horizontal well-cementation expandable cement mortar satisfies requirements on high-temperature and superhigh-temperature horizontal well or high-inclination solid well cementation and has on-site operation feasibility.

Description

technical field [0001] The invention relates to a horizontal well cementing expansion cement slurry and a preparation method thereof, and belongs to the technical field of oil and gas well cementing cement injection. Background technique [0002] The main purpose of the operation is to effectively isolate the annular space outside the casing, prevent formation fluid channeling during drilling, stimulation operations and production of oil and gas wells, provide effective support and protection for the casing, and reduce and alleviate the impact of surrounding rock on the casing. It can improve the stress condition of the casing, prolong the life of oil and gas wells, and ensure the normal production of oil and gas. [0003] In the cementing of high-temperature deep wells and horizontal wells, cement slurry particles may settle due to the failure of some admixtures at high temperatures, resulting in free water and high-edge water zones; or due to the volume shrinkage of cement...

AI Technical Summary

Problems solved by technology

It is mainly reflected that the admixture that can produce suspension at room temperature degrades and loses the suspension at high temperature, the cement slurry settles in the horizontal section to form a high edge water zone, and the expansion agent that can slightly expand the cement stone at medium and low temperatures The expansion effect is not obvious or loses its effect at 110°C, and its use in high-temperature deep well cementing is limited

In addition, adding these expansion agents to the cement will increase the volume fraction of crystals at the interface between the cement sheath and the casing, making the original weak interface bonding quality worse and unable to improve the interface bonding quality

Moreover, the addition of these substances increases the compressive strength of the cement stone, and at the same time increases the elastic modulus of the cement stone, making the cement stone brittle and adversely affecting the later production operations.

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