Cementing Technology Research and Application for Gas Wells with' High Pressure, High H2 S and High Risk' in Chuanyu Area

摘要

In order to continuously increase the cementing quality of complex formations in gas wells with " HP, High H2S and High Risk", and prevent delay pressure on the casing annulus, research and development into cementing technologies, including cementing techniques, slurry systems and cementing tool accessories, has been undertaken. Such technologies include preparations technology of deep wellbore, swirl displacement technology, dry wellbore ce menting technology, prestressed cementing technology, and -pollution technology of slurry, primary and reserved cementing technology, shaking pulse cementing technology, rotating casing, etc. Slurries, such as gas block slur ry with large differential temperatures ranging from 70℃ to 130℃, fiber lost circulation slurry, and high early strength low density slurry have been developed. Furthermore, cementing tools such as a controlled liner hanger, liner packer, and build -in float collar have been produced, and specialized serial cementing technology for wells with "HP, High H2S and High Risk" have been created. Field trials indicate that this series of specialized tech nologies not only has improved cementing quality, but also prevented cementing accidents from occurring. There fore, these technologies have solved the difficulties of cementing in complex formation in gas well with " HP, High H2S and High Risk" in Chuanyu area.