Acidified and consolidated plugging agent

Abstract

The invention discloses a plugging agent capable of being solidified through acidification. The plugging agent comprises the following components in parts by weight: 20-40 parts of shell powder, 30-40 parts of calcium chloride, 10-15 parts of superfine calcium carbonate powder, 0.1-0.5 part of polyanionic cellulose PAC, 0.1-0.2 part of sodium hydroxide, 0.1-0.5 part of XC biopolymer, 0.3-0.6 part of sodium silicate and 0.5-2 parts of potassium silicate. The preparation method comprises the following steps: orderly adding the substances to a reaction kettle according to the components and the content; stirring and mixing under the condition at 40-55 DEG C at normal peruse for 6-8 hours; putting into a dryer to dry for 4-6 hours; crushing into 0.01-0.3mm powdery product. The plugging agent is wide in raw material source, free of toxicity and pollution, good in acid solubility, and strong in sealing capacity, has certain coagulability, is widely applied to petroleum and geological drilling processes, and is especially applicable to application in a reservoir or a reservoir leakage stratum.

Description

technical field [0001] The invention relates to a drilling lost circulation agent, in particular to an acidified and consolidated lost circulation agent. Background technique [0002] There is a fast-setting cement plugging agent used in oil drilling, which is mainly based on cement slurry and various cement mixed thick slurries. Its formula is: 100 parts of oil well cement, 40-50 parts of water, and 5-30 parts of coagulation accelerator According to the lost circulation situation, carefully calculate the amount of cement, water, additives and drilling fluid displacement. This fast-setting cement plugging agent has played a role in the plugging project of oil drilling, but it has the following shortcomings or deficiencies at the same time: ①The cement density is high, the thickening time, solidification time and pumpable time are difficult to control, and it is easy to The rapid loss or rapid curing of cement slurry occurs, and the construction effect and safety are difficu...

AI Technical Summary

Problems solved by technology

This fast-setting cement plugging agent has played a role in the plugging project of oil drilling, but it has the following shortcomings or deficiencies at the same time: ①The cement density is high, the thickening time, solidification time and pumpable time are difficult to control, and it is easy to The rapid loss or rapid curing of cement slurry occurs, and the construction effect and safety are difficult to guarantee; ②It has a great safety risk; ③It will cause great damage to the reservoir, and the fast-setting cement slurry has low acid solubility, low viscosity, fast setting speed, and plugging After condensation, the volume shrinks, free water is easy to appear, and there is a danger of permanent plugging, which will damage the reservoir and reduce the permeability; ④ greatly reduce the oil recovery rate, increase the construction cost, and have no selectivity for the same layer of leakage storage

⑤It is easy to solidify quickly, causing downhole accidents or huge economic losses, directly affecting the plugging effect and drilling engineering