Preparation And Anti-swelling Properties Of The Composite Ion Tannin

Exploitation of low permeability oil fields, for China’s oil industry, has a pivotal position. Clay reservoir with low permeability has water sensitivity characteristics, therefore, inhibiting hydration expansion in oil production process becomes more necessary, and during drilling, borehole stability is the prepare conditions of ensuring the drilling’s smooth progress, so rational use of anti-sloughing agent is very important. So the research on clay stabilizers and anti-sloughing agent becomes the content which experts and scholars continue to delve into in the field. This article was used tannin as a raw material to prepare complex ion tannin, used as the clay stabilizer, as well as their use in the field of horizontal well drilling fluid.In this paper, tannin extract, as raw materials, reacts with epichlorohydrin, dimethylamine, concentrated sulfuric acid and diethylenetriamine by using three different methods, namely first cationized then sulfonated, sulfonated and cationized then polymerized, the third one, first suffocated and then cationized. In using these three methods for preparing complex ions tannin, the optimal experimental conditions were carried out, the result is, optimal reaction conditions of first cationized then sulfonated product: temperature is 60°C, the reaction time is 6h, pH value is 8. The optimum condition of the product obtained by the second method is: temperature 50°C, reaction time 5h, pH value 8. The optimal reaction conditions for the third product is: temperature 55°C, the reaction time 5h, pH value 8.In the anti-swelling compound ions tannin performance study, compatibility test verifies the feasibility of the three products as a clay stabilizer, the experimental data of core recovery suggests that the stability of complex ion tannin polymer3 is better than 1 and 2. At a concentration of 0.5%, the expansion of complex ion tannin polymer 1 and 2 are 2% and at 0.7% concentration, the expansion of 3 is 2.2%. Results using the centrifugal method are, at 0.7% concentration, the stability of complex ion tannin polymer 3 is the best at 0.5% concentration, the stability of tannin complex ion tannin 1 and 2 is the best, and the product stability of 3 is better than 1 and 2. The complex experiments, stability of after complex is better than before, and the ratio of complexion with KCl are: 1:2.5,1:2,1:3; and the complex results of Al5(OH)3 are:1:3,1:3,1:3.The core flow experiments determines the stability of tannin product 3, which was prepared by first sulfonated and then cationized process, is the best, and in this moment, the reaction condition is: temperature 45°C, concentration0.7%, the reducing value of anti-swelling rate is lower 20.53%. In the complex ion tannin study of the anti-collapse of horizontal well drilling, the leaching loss rate testing is conducted, the anti-collapse of polymer 3 is better than 2 and 1, the value that leaching loss rate less than polymer 1 is8.26%, less than polymer 2 is 2.52%. By experiments of flexural capacity and compressive strength, polymer 3 has a strong resistance to fracture and compression capabilities.