Synthesis And Performance Evaluation Of An Acidic Spin Direction Agent

In our country, heterogeneous reservoir is abundant. Conventional acidification technique is used to transform this kind of reservoir, and the acid solution can be used to refer to the large channel or high permeability part of heterogeneous reservoirs. For this kind of reservoir, it is need to use the steering acidification technology to achieve the purpose of uniform transformation. Viscoelastic surfactant self steering acidizing technology is a new technology to transform heterogeneous formation.It is easy to prepare,easy to break.In the interior from erucic acid and N, N-dimethyl propylene diamine by amidation, quaternization reaction synthesized acidization self steering agent erucic acid amide propyl betaine. The optimal reaction conditions were obtained by optimizing the synthesis conditions. Optimal experimental conditions for amidation of reaction temperature of 150°C, potassium hydroxide catalyst dosage was 0.6wt%, erucic acid and 3-dimethylamine propyl ammonia molar ratio was 1:1.3, reaction time was 7.5 hours. Optimal experimental conditions quaternization reaction is 80°C,ratio of tertiary amine and sodium chloroacetate of substance ratio of 1:1.2, the reaction time is 7 hours. Through the infrared spectrometer on the product was analyzed by infrared spectrum, confirm the compositions of erucic acid amide propyl betaine.Erucic acid amide propyl betaine concentration, temperature, pH, shear, Fe3+ concentration, ferric ion stabilizer, corrosion agent effect on the viscosity of the acid were measured. The spin direction agent has good temperature resistance and shear thinning property. Turning acid by pH value, when the pH=4 viscosity reached the maximum value.Through the core experiment to simulate the acid liquid turning, adding the self steering agent to improve the effect of the steering effect is obvious.Double low permeability core permeability was increased by 40.67 percent, triple the low permeability core permeability was increased by 29.02%。It can effectively improve low permeability core.Self-steering acid has good compatibility energy, able to adapt to a variety of acid formulations. Kerosene, water was used to simulate formation hydrocarbon and formation water for gel breaking experiment. The use of kerosene at high temperature conditions to break the gel time is shorter, the gel breaking effect is better. The residual acid system can break the rubber at high shear rate. However, in the case of no shear or shear rate is very low, even for a long time it is very difficult to break the glue, then need to join the gel breaker.