On December 23, Zoranoc company completed the cementing operation of 177.8 + 184.15mm composite liner fine pressure control pressure balance method for double exploration well 6, and renewed the new cementing record of the deepest composite liner running in, the longest open hole section and the longest sealing section in Sichuan and Chongqing.

Shuang exploratory 6 well is located in Taiqing village, Xiuzhong Township, Jiange County, Guangyuan City. It is a rolling appraisal well deployed by Zoranoc company in the structure of shuangyushi hewanchang in Northwest Sichuan. The design depth of the well is 8205m. The drilling purpose is to evaluate the reservoir and its oil and gas bearing property of Qixia Formation and explore Maokou Formation.

This well is designed to use five unconventional well bore structures. This time, 241.3mm bit is used to sidetrack to 7833m, 177.8 + 184.15mm composite liner is put in to seal 3245-7833m, 443t empty weight (327t floating weight) is put into the well string, so it is very difficult to run the casing safely.

This cementing is mainly faced with such problems as simultaneous injection and leakage, narrow safety density window and large annular friction. The equivalent density of Maokou Formation gas reservoir is 1.98g/cm3 when the pressure is stabilized at 7605m, and the pressure bearing capacity of Maokou Formation leakage layer at 7811m is only 2.03g/cm3. It is difficult to stabilize and prevent leakage during the cementing process, and the cementing quality and construction safety are facing severe challenges.

Zoranoc company formulates corresponding technical measures according to the key points and difficulties in the construction process, and adopts fine pressure control cementing and "three condensate systems" to solve the problems of leakage and injection. At the same time, the reasonable selection of wiper string, optimization of cementing parameters, and further improvement of cement slurry performance.

After 5 hours of construction, Zoranoc company successfully completed 177.8 + 184.15 mm composite liner hanging cementing construction of double exploration well 6, laying a good construction foundation for subsequent drilling and testing operations, and providing technical support for subsequent well location deployment in the block.