Chelate blocking remover suitable for complicated scaling reservoir layers, and preparation method of chelate blocking remover

Abstract

The invention provides a chelate blocking remover suitable for complicated scaling reservoir layers, and a preparation method of the chelate blocking remover. The chelate blocking remover is prepared from the following components by mass percent: 5-20% of a chelating agent, 0.5-1% of a scale inhibitor, 1-5% of an activator, 0.5-2% of a penetrant and the balance of distilled water. The chelate blocking remover can remove most of complex blockages, formed by complex inorganic scale such as carbonate scale and sulphate scale, and organic scale at immediate vicinity of wellbore zones with scaled oil reservoir, can inhibit the growth of the scale, and prolongs the action time. The chelate blocking remover is mainly used for removing complex scale blockages such as calcium carbonate, calcium sulfate, barium strontium sulfate scale and iron sulfide; the scale blockages are removed by means of saturated dispersion, chelating solubilization and crystal nucleus distortion; the chelate blocking remover can be used for dredging seepage channels of shafts and stratum, reducing oil gas water flow resistance, increasing the yield of an oil-gas well and reducing the injection pressure of a water injection well; furthermore, the chelate blocking remover has certain corrosion inhibition property and dissolution property, thus meeting the blockage removing conditions of the complicated scaling reservoir layers.

Description

technical field

[0001] The present invention relates to a kind of chelating blockage-removing agent suitable for complex scaling reservoirs and its preparation method, in particular to reservoirs containing scales of various complex components, such as carbonate scale, sulfate scale, refractory Silicate, iron sulfide, etc., through strong chelation solubilization and removal of blockages, can effectively expand the radius of blockage removal, reduce the water injection pressure of water wells, and prolong the stable production period of oil wells. Background technique

[0002] Scaling is an unavoidable problem in the development of oil and gas fields. In the process of oil and gas extraction, formation fluid passes through perforation holes, wellbore, and wellhead, and the pressure and temperature of the environment where the fluid is located changes. The original chemical balance of scale ions in formation water is broken, resulting in the deposition of inorganic salts and ...

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