Drilling Fluid Technology of Complicated Formation in Zheng 11 Well
QIU Chun-yang;WU Xiao-wen;WEN Shou-yun;ZHANG Hai-qing;CHEN Er-ding;WANG Bao-tian;Drilling Engineering Technology Corporation,Shengli Petroleum Engineer Co. ,LTD;
Zheng 11 well was an important exploration well,and was located in the first oilfield in Junggar Basin. The total depth was 4 540 m. The petrography character was very complicated in down formation in the area. Blockage tripping easily occurred because hydrous disintegration of argillutite in Tuguluqun formation. Crisp collapse often occurred in Xishanyao formation because compressive strength and rupture strength of coal bed was poor. Stress collapse about hard and crisp mudstone occurred usually in Sangonghe formation. The wellbore was very instabile because barefoot interval was long and drilling term was long. The target stratum was drilled after poly-amine formation sealing and anti-caving drilling fluid was used. With the help of onsite drilling fluid maintenance and handling technics,and technology measure of dealing with the complex situation,the demand of drilling operation was met.
【CateGory Index】： TE254