Low-temperature early-strength salt-resistant well cement slurry system

Abstract

The invention discloses a low-temperature early-strength salt-resistant well cement slurry system comprising 100 parts of class-G oil well cement, 0.8-1 part of low-temperature salt-resistant fluid loss agent, 2-3 parts of compound early strength agent, 0-13.5 parts of hollow glass micro-beads, 0.2-0.5 part of dispersant, 3-4 parts of micro-silicon and 41-81 parts of salt water. The low-temperature early-strength salt-resistant well cement slurry system can realize well cementing in the density range from 1.50g / cm<3> to 1.90g / cm<3>, is good in low temperature resistance, strong in salt resistance, safe and convenient for on-site construction, good in well cementing quality, and provides a reliable and safe guarantee for well drilling and oil production.

Description

technical field [0001] The invention relates to a cement slurry system for well drilling and cementing in oil and gas fields, in particular to a low-temperature early-strength salt-resistant cement slurry system. Background technique [0002] In the surface casing cementing process of oil and gas fields, due to the low formation temperature and easy to see salt layer, the strength of cement stone develops slowly and the curing time is long, which leads to the increase of drilling cost and high risk of on-site construction. [0003] At present, latex is commonly used as fluid loss reducer and calcium chloride as composite early strength agent in low temperature salt-resistant cementing slurry system in oil fields. The disadvantage of latex as a fluid loss reducing agent is that it is added in a large amount, and the API water loss is too large, and it is easy to hang in the cement tanker and is difficult to clean, resulting in higher maintenance equipment costs. Although cal...

AI Technical Summary

Problems solved by technology

The disadvantage of latex as a fluid loss reducing agent is that it is added in a large amount, and the API water loss is too large, and it is easy to hang in the cement tanker and it is difficult to clean, resulting in higher maintenance equipment costs.

Although calcium chloride is used as composite early-strength agent, the early strength can be improved, but the chloride ions will seriously corrode the casing after cementing.

[0004] Using the existing cementing materials to design low-temperature cementing slurry system is difficult and has high risks in site construction. Therefore, it is necessary to develop supporting low-temperature cementing cement slurry system with low-temperature fluid loss reducing agent and composite early strength agent.

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