Study On Preparation And Properties Of High Temperature Gel Used In The Oil Field Production

Water flooding method is generally adopted in oil filed across our country. In the oil production tail, water content increases rapidly and geologic parameter is getting complicated in the middle and terminal time. For big thickness and the major serious heterogeneity oil pool, after the long-term injected water scouring, the pore structural features of reservoirs have changed greatly. Most injection grout penetrates along the high permeability zone of each sedimentary unit of thick reservoir, which will cause the chemicals circle invalid and limit the mount of oil extracted from reservoirs, resulted in the water thickness basically unchanged. There was a serious phenomenon, which is inefficient and invalid circulation, so as to restrict improvement of oil production. Therefore, Profile control is required in the water plugged wells.In this report, we mainly chose konjac powder (KGM) which source is extensive as a gel lord agent, and prepared high temperature resistant konjac gel by using a cross-linking agent called M and a delayed cross-linking called N as cross-linking agent. We also added a tiny amount of polyacrylamide (PAM) and conditioning agent called J into the gel. The resin gel formation time, strength and shape were showed affected by the contents of the essential various additives. The optimized compound design was obtained through the experiment analysis as:KGM 4.7g/L+ PAM 0.094g/L+ conditioning agent J 0.118g/L+ cross-linking agent M 0.23 vol% + delayed cross-linking agent N 0.47 vol%. The modality of gel is very stable and the strength is high in range of 90 and 155℃. And the strength of high temperature gel is also high after 15 days under environmental temperature of 90℃. The gel has good salt resistance performance. The strength of the gel is high and the modality of gel is very stable, in the range of concentration of NaCl 10000～80000mg/L, concentration of CaCl2 400～1000mg/L and concentration of MgCl2 400～1200mg/L.The results from the core displacement test showed that the blocking rate of cores and the breakthrough pressure are both high in different permeability core tubes; The blocking rate of cores and the breakthrough pressure of this gel gradually increased with the increasing of injected volume of gel adjustable profile control agent. With the increasing of water-flood injection rate, the blocking rate of cores reduced, while the breakthrough pressure increased. This profile control agent has good salt resistance performance. After 20PV water injection profile control agent, the blocking rate of cores of this gel still reached 92.15%. It has very good resistance to erosion performance. This gel's residual resistance factors were more than 130. Through parallel cores simulation experiment, we can see that the gel firstly reached the high permeability pore area, and reduced the permeability of big porosity area. Using this gel as adjustable profile control agent for profile homework, it will effectively ameliorate water-injecting profile of stratum. So it can improve the recovery of crude oil.