Research On Small Cationic Clay Anti-Swelling Agent Application Performance

In low permeability reservoir, clay content is high, pore throat radius is small and penetration is low generally. With the stability of clay in low permeability reservoir, using high molecular weight cationic polymer clay stabilizing agent deal with low-permeability reservoirs are able to achieve purpose of anti-clay expansion, but the polymer adsorption at the pore wall will reduce or block the pore throat of low permeability, reservoir permeability is reduced, increasing the damage to the reservoir, therefore, development and use of low permeability reservoir adapted to small molecular weight of clay stabilizer to become a top priority.Relative molecular mass of small cationic compounds, commonly referred to as the small cations, it mainly refers to the short-chain quaternary ammonium small cations under normal circumstances do not have surface activity, but also that they are cationic surfactants active agents.The small cationic compounds, stabilizers, anti-swelling clay is mainly used in low-permeability reservoir drilling, water injection, fracturing, acidizing, and perforation, in the protection of reservoir permeability, cationic compounds with relative molecular larger mass of the cationic polymer can not be compared, unique fine performance, the use of small cations in low permeability reservoirs as clay anti-inflation stabilizer is a not only a long period of stable clay particles while protecting an effective way of reservoir permeability.2-chloroethyl trimethyl ammonium chloride, or CETA, is an organic quaternary ammonium cationic compounds, the positive charge density is high, relative molecular mass is smaller, when added to water, ionization of the organic cation can adsorption protective film formed of a layer of organic cationic compounds in the surface of the clay particles by electrostatic adsorption on the surface of the clay particles, clay particles protected to prevent hydration swelling of clay particles and dispersed migration play a stabilizing clay particles the role, very suitable for use as a low permeability reservoir clay anti-swelling stabilizer.In a large number of home and abroad clay stabilizer anti-expansion literature, this paper intends to expand the experiment from the following aspects:1) High water sensitivity characteristics of the reservoir and its water sensitivity in the water injection development process damage, choose a smaller relative molecular mass of quaternary ammonium cationic compounds2-chloroethyl trimethyl ammonium chloride (CETA), anti-swelling clay stabilizer, and comprehensive use of advanced modern technology to analyze the test means to prevent the clay from2-chloroethyl trimethyl ammonium chloride (CETA) and formation water compatibility of the best use concentration2chloroethyl trimethyl ammonium chloride (CETA), anti-swelling clay stability, persistence, the recovery rate of cuttings, core crushing rate and core permeability of the expansion effect of a comprehensive evaluation, better to prevent clay swelling effect, proved that the2chloroethyl trimethyl ammonium chloride (CETA) as a very broad application prospects of anti-clay swelling stabilizer;2) For low permeability reservoirs can easily water lock harm in the problem,2-chloroethyl trimethyl ammonium chloride (CETA) surfactant compound developed waterproof lock damage agent, TA-2Series and interfacial tension experiments, the core flow tests and core scroll experimental analysis evaluated2-chloroethyl trimethyl ammonium chloride (CETA) in the TA-2Series waterproof lock damage agent application performance, the results show that:TA-2Series waterproof lock agent has a good waterproof locking effect;3) Aim to clay hydration swelling caused by sidewall instability,2chloroethyl trimethyl ammonium chloride (CETA) in order to improve the suppression of the drilling fluid to the drilling fluid, the basic properties of the CETA/montmorillonite system was investigated by ζ, potential changes, the relative wetting contact angle, adsorption and X-ray diffraction methods, confirmed the feasibility of CETA can be applied to the inhibition water base drilling fluid.