Studies On Synthesis And Application Of New Clay Stabilizers For More Vulnerable Well Killing Fluid

Clay minerals is widespread in the formation, there are three principal types of Clay minerals, for example kaolinite, montmorillonite, illite and so on. In this paper, clay mineral particles because of hydrated expansion and dispersed migration give rise to the peoblem of permeability declining of the reservoir. Three clay stabilizers have been synthesized using 1,2-propanediol(1,4-butanediol, glycerol), epichlorohydrin, ammonia, etc by ring-opening polymerization and amination. Meanwhile, the most effective syhthetic condition of the three clay stabilizers was obtained experimentlly. Lop-1, Lop-2 and Lop-3 were recorded as the most effective syhthetic condition of the three clay stabilizers. Lop-1 and Lop-2 were screened because of higher raw material utilization. Antiswelling resistance, temperature resistance, acid and alkali resistance, long term efficiency, compound with inorganic salts,compatibility with the killing fluid and core flooding etc of the two clay stabilizers were evaluated comparing with a commercial organic amine clay stabilizer, Bop-3 by using anti-swelling ratio as an important indicator.When 1,2-propanediol and 1,4-butanediol are made use of as the initiator, the best ratio of the amount of substance of them and epichlorohydrin are 1:8, the best amount of sodium ethylate as catalyst is 5% of the amount of substance of these two diatomic alcohol, the optimum conditions for the amination reaction is that the best reaction temperature is 110 ℃, the best reaction time is 6 hours, the best ratio of the amount of substance of ammonia and chloromethyl is 5:1; when glycerol is used as the initiator, the best ratio of the amount of substance of glycerol and epichlorohydrin is 1:9, the best amount of sodium ethylate as catalyst is 5% of the amount of substance of glycerol, the optimum conditions for the amination reaction is that the best reaction temperature is 130 ℃, the best reaction time was 8 hours, the best reaction time is 6 hours, the best ratio of the amount of substance of ammonia and chloromethyl is 5:1.When costing 2% of Lop-1 and Lop-2, the anti-swelling of them can reach 83.67% and 80.93%, so the anti-swelling effect is better. The anti-swelling of these two clay stabilizers can change a little as the varieties of temperature and p H at a certain concentration, that is to say, temperature resistance, acid and alkali resistance of these two clay stabilizers are good. The results showed that the two clay stabilizer with good long-term stability of clay and anti-swelling agent at different concentration, the rate of resistance to washing can be reach above 90% comparing with Bop-3. The anti-swelling effect of Lop-1 and Lop-2 two-mixed or three-mixed with inorganic salt potassium chloride, ammonium chloride are better than used on its own. Lop-1 and Lop-2 mixed evenly with the scene well killing fluid, the mixture can be transparent, no precipitation, no stratification, thus Lop-1 and Lop-2 with well killing fluid in construction site have a good compatibility. Furthermore, natural coer was polluted by the two clay stabilizers and K3 / K2 value can reach 93.97%-95.09% with excellent reservoirprotection effect in core experiments.