Method for transforming and injecting gas by using old shaft

• Main Authors: WANG ZHIGUO, TAN JUNLING, XUE JIANQIANG, YANG FEITAO, MENG XIN, ZHANG WENXING, ZHAO GUANGMIN, GUI JIE, SHI CHENG'EN, WANG ZAIQIANG
• Format: Patent
• Language: Chinese; English
• Published: 27.10.2020
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

The invention provides a method for transforming and injecting gas by using an old shaft. The method comprises the steps that after a novel hermetic sealing oil pipe is lowered to an artificial well bottom of the target old shaft, secondary well cementation and re-perforation are sequentially carried out, a novel gas injection well mouth is installed, the long-term sealing performance of a well completion structure after transformation is ensured, an existing water injection well or an existing oil production well is fully utilized, the problem of high cost caused by rebuilding a novel well inconventional old shaft transformation is solved, gas injection tools such as a hermetic seal packer, a shear ball seat and a guiding shoe do not need to be lowered, the tool cost is saved, and a pipecolumn is simpler and more reliable. The method is particularly suitable for the situation that during gas injection development of oil reservoirs for carbon dioxide flooding, oxygen-reduced air foamflooding, natural gas floo