High temperature and high pressure resistant organic compound oil layer protection fluid and preparation method thereof

Abstract

The high temperature and high pressure resistant organic compound oil layer protection fluid and the preparation method thereof of the present invention relate to the technical field of oil field chemical industry, and are composed of 3 to 6 parts of polyacrylamide, 2 to 5 parts of oxidative crosslinking agent, and 2 parts of inorganic coagulant accelerator. ~8 parts, 63~88 parts of water and 5~18 parts of 98% ethanol. The preparation method is to dissolve polyacrylamide in water, then add ethanol solution of oxidative crosslinking agent, and stir at 35~60℃ for 1~ After 5 hours, finally cool the mixture to 20-30°C, add 2-8 parts of inorganic coagulant, and stir for 30 minutes to obtain the finished product. The high temperature and high pressure resistant organic composite oil layer protection fluid of the present invention has a density range of 1.05g / cm3 to 1.35g / cm3, a long action period of the inorganic anti-swelling component, a chloride ion content of less than 300mg / L, no heavy metal ions, With low viscosity and low fluid loss, good thermal stability.

Description

technical field [0001] The invention relates to the field of oilfield chemical technology, in particular to a high temperature and high pressure resistant organic composite oil layer protection fluid and a preparation method thereof. Background technique [0002] In the process of oil and water well construction, the correct selection of oil layer protection fluid can not only protect the formation, tubing, casing and downhole equipment from secondary damage or damage, but also prevent formation voids from being blocked, avoid downhole equipment from being corroded, and effectively prolong Formation and well life. In recent years, during the construction and operation of ordinary oil-water wells and gas wells, a large number of protective fluids with chlorides as weighting agents have been used in large quantities. Reduce the permeability of the bottom layer; second, it is easy to interact with formation water to form precipitated insoluble matter and reduce porosity; third...

AI Technical Summary

Problems solved by technology

In recent years, during the construction and operation of ordinary oil-water wells and gas wells, a large number of protective fluids with chlorides as weighting agents have been used in large quantities. Reduce the permeability of the bottom layer; second, it is easy to interact with formation water to form precipitated insoluble matter and reduce porosity; third, it is easy to corrode the relevant downhole casings and equipment, causing a large amount of surface corrosion and pitting corrosion on the surface, which affects the service life. Especially in some gas wells and gas testing operations, the protection fluid has seriously corroded the oil casing, and the protection fluid poured back into the formation during the well killing process.

In addition, protective fluids with conventional densities are likely to cause construction resistance during construction, especially for low-permeability, low-pressure, and low-abundance "three-low" oil and gas reservoirs. Protective fluids that do not match the formation will cause permanent damage to the formation. harm