Filtrate reducer for oil field well drilling fluid

Abstract

The invention relates to an oil field fluid loss additive for drilling liquid and its producing method and the application of the treating agent in the process of producing drilling liquid system. The treating agent utilizes the cation monomer dimethyl diallyl ammonium chloride can make the sodium lignin sulfonate and the sulfonated-methyl brown coal graft induced by FeCl3 so as to produce a new fluid loss agent with the resistance to salt and collapse at high temperature. The composed product integrates the brown coal and lignin. The cation introduction improves the resistance to collapse. The weak crosslinking function of the Fe3+ makes the heat resistance improved further based on the brown coal. Therefore, the product can be widely applied in different complicated conditions such as high temperature deep well, gypsum / slat bed, stratum with a bad water sensitivity, fragility stratum and etc. and has a good prospect.

Description

technical field [0001] The invention relates to an additive for oilfield drilling fluid, more specifically, to a fluid loss reducer for oilfield drilling fluid. The treatment agent has the ability to resist high temperature and salt intrusion. technical background [0002] In oil drilling operations, when the drilling fluid flows through the permeable formation under pressure, it will infiltrate, causing the liquid phase of the drilling fluid to infiltrate into the formation. This process is collectively called "water loss". If water loss cannot be well controlled, a large amount of water loss entering the formation will not only induce wellbore instability, but also cause damage to oil and gas formations. At present, the effective way to solve this problem is to add fluid loss control agent in the drilling fluid. [0003] The fluid loss control agents used in oilfield drilling fluid mainly include the following types: [0004] (1) Special ultrafine particle materials, suc...

AI Technical Summary

Problems solved by technology

However, field use shows that iron-chromium salts will lose their effectiveness at temperatures above 130°C, and irreversible degradation will occur when the temperature exceeds 177°C

Therefore the synergistic effect of sulfomethyl lignite and lignosulfonate is limited

Especially in the case of high temperature and high salt, the two will not be able to play a role due to their own shortcomings.

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