Drilling in fluid technology for the sidetracking Well Xing A6-6 in Jilin Oilfield

Well Xing A6-6 is a sidetracked hole in Shuangyang area of Jilin Oilfield, and its penetrating formation is Ee section of the lower Tertiary system, which is mainly consisted of mudstone and sand stone. The testing results of system optimization show that the silicon-based polymer drilling fluid has such ad-vantages as good stability and inhibition, adjustable rheology and minimum formation damage, and it can fully meet the requirements of drilling operation in this area. Organic silicon based polymer drilling fluid, as well as completion fluid mainly composed of organic silicon and polymer were used. At a hole depth of 1803. 30 m after sidetracking, 3 % of crude oil was added into to improve the lubricity, rheology and mud cake quality. Field using showed that the drilling fluid has better cuttings transportation, better inhibition, stability and lubricity. Later test production showed that the completion fluid is very effective for reservoir protection, it dramatically improved the production rate of this well. The drilling period of this well was 15. 96 d, ROP was 2. 53 m/h, and no stuck pipe and lost circulation were encountered.