Method for preparing fluid loss agent

Abstract

The invention provides a method for preparing a fluid loss agent. The method comprises the following steps of: a) mixing phenol, sulphuric acid, trimethylamine and a first solvent, and reacting to generate cation phenol; b) mixing an alkaline aqueous solution, lignite and a second solvent, and reacting to obtain sodium humate slurry; and c) mixing the sodium humate slurry with cation phenol, sodium sulfite and a third solvent, and carrying out polymerization to obtain the fluid loss agent. The fluid loss agent provided by the invention is obtained by firstly carrying out cationization on phenol, mixing with the sodium humate slurry and carrying out polymerization, both a humic acid group and a sulfonated phenol group are contained in the molecule of the fluid loss agent, a molecular chainis longer, and a sulfonic acid group has strong inhibition and tolerance effects to various metal ions in soil, thus mud viscosity can not be improved, a mud cake formed by a drilling fluid and soil is compact and is difficult to collapse. Besides, a benzene ring exists, thus the fluid loss agent prepared by the preparation method provided by the invention also has the characteristics of high-temperature resistance and high-pressure resistance.

Description

technical field [0001] The invention relates to the field of polymer synthesis, in particular to a preparation method of a fluid loss reducer. Background technique [0002] In oil exploration or drilling operations, the drill bit is easily damaged under the action of huge pressure and friction, so drilling fluid is used to protect the drill bit during drilling operations, but the drilling fluid will seep into the formation soil under pressure and cause loss , this process is commonly referred to as "dehydration". A large amount of water loss entering the soil will not only induce wellbore instability, but also cause damage to oil and gas layers. The current solution to this problem is to add fluid loss reducers to drilling fluids, which can block all directions The capillary channels in the mud cake formed by drilling fluid and soil make it smooth and dense; increase the negative charge density of the mud cake to form a strong polarized water layer; the molecules of the flu...

AI Technical Summary

Problems solved by technology

[0003] Currently widely used fluid loss reducers use aqueous solution polymerization or inverse emulsion polymerization. Taking aqueous solution polymerization as an example, water-soluble raw materials are dissolved in water to form an aqueous solution, which is directly polymerized with oil-soluble monomers. complete, the reaction efficiency is low, and the reaction heat of aqueous solution polymerization is unevenly distributed, resulting in local overheating in the aqueous solution. Local overheating will cause crosslinking of the polymer and increase the viscosity, which cannot be used as a fluid loss reducer; while the inverse emulsion polymerization method It is to dissolve the water-soluble raw material in the aqueous solution and then disperse it in the non-polar liquid through the emulsifier to form a water-in-oil type emulsion, which avoids the local overheating during the polymerization process, but the reduction in the preparation of the inverse emulsion polymerization method The dehydration agent is unstable, and the dehydration agent obtained by inverse emulsion polymerization will be separated or even collapsed after being placed for a long time or under high temperature and high pressure, which will affect the performance of the dehydration agent

[0004] In addition to the functions of conventional treatment agents, the anti-high temperature anti-slump and fluid loss agent also has a strong ability to inhibit shale expansion and dispersion, so as to meet the needs of stabilizing the well wall, preventing collapse, and controlling formation slurry. It is easy to cause mud viscosity increase, so its application is greatly restricted

Images