新型高密度清洁复合盐水完井液

A New High Density Solid-free Clear Saltwater Completion Fluid

为了研究一种价格低廉的新型高密度清洁复合盐水完井液,对常见的无机盐氯化钙和氯化锌使用增溶剂,提高其在水中的溶解量,来达到在不增加完井液固相含量的同时提高完井液密度的目的。通过室内实验筛选出2种增溶剂,得出2种增溶剂在2%LAS-30+2%SLF-4的用量下增溶效果最好,在该用量下2种无机盐复配后所配制的清洁盐水体系的最大密度可以达到1.926 g/cm^3,此时氯化钙的溶解量为160 g/100 m L水,氯化锌的溶解量为98 g/100 m L水。新型完井液的表观黏度为33 m Pa·s,抗温可达140℃,渗透率恢复值高达96%,保护储层性能良好。

In laboratory studies, solubilizing agent was used to increase the solubility of commonly used inorganic salts such as CaCl2 and ZnCl2 to formulate a new cost-efficient high density solid-free clear saltwater completion fluid. The addition of inorganic salts in a completion fluid increases the density of the fluid while not increasing its solids content. Two solubilizing agents were selected through laboratory experiments, which performed best in a solution containing 2%LAS-30＋2%SLF-4. A clear saltwater completion fluid prepared with the said solution can have density of 1.926 g/cm3 with compounded inorganic salts. At this density, the concentration of CaCl2 is 160 g/100 m L water, and the concentration of ZnCl2 is 98 g/100 m L water. The new completion fluid has apparent viscosity of 33 m Pas, temperature tolerance of 140 ℃, and recovery of damaged permeability as high as 96%. This completion fluid performed very well in reservoir protection.