COMPLETION METHOD AND CEMENTING TECHNICAL MEASURES OF SEA COAST AREA MULTI-TARGETS EXTENSION WELLS WITH GREAT DISPLACEMENT

The cementing quality of se coast area multi-targets extenslon wells with great displacement was assured through application of a series of technological measures such as rational locatlon of casing centrallzers, optimized selection of cement and cement addltives with assistance of weighing and torque measurement of liner-small size drill pipe, prolong lng thlckening effect of cement slurry, adjusting injection and return velocity of cement slurry. The technological process of cementing of φ339.7 mm surface casing, φ273 mm and φ177.8 mm technical casing and pressurized cementing of φ127 mm liner were analyzed and the design of casing string and casing centralizers and compatibility tests of G 601 filtra tion control agent, G 602 cross-linking agent and H 88 retarder were also studied in this paper. The experiences of cementing of great size technical casing, great depth regular size technical casing, deep well pressurized liner cementing in multi-targets wells with great dis placement and massive extra tension of casing were summarized.