关键词: 柴西地区, 探井, 胶凝酸多级注入酸压技术, 水力加砂+返排技术, 醇酸酸化技术, 油基压裂技术

Abstract: The reservoir in the western region of Qaidam Basin in Qinghai Province is a typica lmarlstone reservoir with low porosity and low permeability, in which ca rbona te rock, cla stic rock a nd mudstone account for the same proportion respectiv ely. It is difficult to improv e such a kind of reservoir for its difference from pure carbonate rock reservoirs a nd pure sa ndstone rock reservoirs. By a pplying the techniques of gel acid fracturing, hydraulic sand a nd flowback, alkyd a cidizing, and oil base fra cturing, 43 times of technical tra nsformation ha ve been carried out in various exploration wells of the region including 12 times of acidizing, 20 times of acid fracturing, and 11 times of sand fracturing. The success rate of acid-fracturing and acidizing operation is far higher than that of sand fracturing, a nd the field operation parameter and the design coincidence ra te a re both kept a t more than 85 percent. The results show that 80 percent of the explora tion wells see an increasing fluid production ba sed on the reservoir reconstruction, with the avera ge fluid flowback rate being 65 percent

Key words: the western region of Qaidam Basin, exploration well, multiple injection acid-fracturing technique in gel acid, hydraulic sa nd and flowback technique, alkyd acidizing technique