Heatproof water invasion-resistant gel cement mortar

Abstract

The invention discloses a heatproof water invasion-resistant gel cement mortar. The heatproof water invasion-resistant gel cement mortar comprises G-grade oil well cement, a conditioning agent, a delayed coagulant, a dispersant and a filling material; the mass ratio of the G-grade oil well cement to the filling material is 1: 0.6-1; the mass sum of the G-grade oil well cement and the filling material is taken as a reference, the conditioning agent, the delayed coagulant and the dispersant account for 8-16%, 0-2% and 0-1% of mass percentage; a method for preparing the conditioning agent comprises the following steps: sodium hydroxide is dissolved in water, after heat dissipation, a monomer is added, after deoxygenation, an initiator is added, the materials are reacted for 3-4 h at the temperature of 50-65 DEG C, the material is cooled to room temperature; wherein the monomer is a mixture of a N,N dimethylacrylamide monomer, an acrylamide monomer, a 2-acrylamide-2-methylpropanesulfonic acid monomer and an acrylic acid monomer. The cement mortar has good water dilution-resistant capability under high temperature, cannot be easily dispersed in water, is not easily polluted by stratum water, can adjust the thickening time of the cement mortar according to construction time, and can plug a ground layer.

Description

technical field [0001] The invention belongs to the fields of petroleum drilling engineering and coalbed methane engineering, and in particular relates to a temperature-resistant water-invasion-resistant gel cement slurry. Background technique [0002] At present, the plugging agents used in oil fields for water plugging, profile control, and layer leakage mainly have the following problems: 1) The plugging slurry of organic plugging agents has poor strength after consolidation, insufficient temperature resistance, and short validity period; The plugging agent with good effect has high cost and is not suitable for large-dose plugging construction. 2) The milk of lime in the inorganic plugging agent has low cost and is the most common technology in China. However, milk of lime is easily washed out by water in water, has poor water intrusion resistance, and the reaction time is not easy to control. The particles are large and easy to settle at the bottom of the well. The laye...

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Problems solved by technology

[0002] At present, the plugging agents used in oil fields for water plugging, profile control, and layer leakage mainly have the following problems: 1) The plugging slurry of organic plugging agents has poor strength after consolidation, insufficient temperature resistance, and short validity period; The plugging agent with good effect has high cost and is not suitable for large-dose plugging construction

2) The milk of lime in the inorganic plugging agent has low cost and is the most common technology in China. However, milk of lime is easily washed out by water in water, has poor water intrusion resistance, and the reaction time is not easy to control. The particles are large and easy to settle at the bottom of the well. The layer is more harmful; the ultra-fine cement has the technical difficulties of small affected volume and poor construction safety, and cannot effectively stay in the plugging layer. The injection volume of plugging is large, and the construction time is long

Once the plugging fails, firstly, it will cause complicated drilling, and secondly, some underground rivers are connected with local water sources, which will cause pollution and cause environmental accidents

[0004] When cement plugging is used to block the target formation, the cement slurry is easily washed out and diluted during the pumping process due to the existence of formation water, brine layer or polluted water source underground, which may cause pollution to the cement slurry and cause the cement slurry to grow. Time does not freeze, it needs to be plugged twice, or even three times, to increase the construction period

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