Ultra-Short Liner Cementing Technology for Highly Deviated Wells in the Chenghai Oilfield

In the Chenghai Oilfield’s highly deviated wells, the intermediate casing cannot be run to the correct depth, so that the water layers cannot be isolated. During the remedial cementing with ultra-short liners, there are such problems in the highly deviated segments as low hang weight, difficulty in releasing and its identification, an active water layer susceptible to channeling, a poor centralization grade of the liner, and low displacement efficiency. For that reason, the ultra-short liner cementing technology for highly deviated wells was investigated. A hold-down sub installed under the parker-type liner hanger could increase the hang weight of the liner. The expanding cement slurry system was used to prevent the formation water from channeling. The centralizer position was optimized with PVI to raise the centralization grade of liner, and the structure and rheological properties of cementing slurry column were optimized to improve displacement efficiency. The ultra-short liner cementing technology for highly deviated wells was then developed. The technology was applied in two highly deviated wells in Chenghai Oilfield, with a high downward force of the hold-down sub, successful liner releasing and evident identification of it, and well isolated oil-water layers. In the later production rounds, stable and high oil flow was obtained. The research demonstrates that the ultra-short liner cementing technology for highly deviated wells solves the problem of ultra-short liner cementing for highly deviated wells in the Chenghai Oilfield, and also provides a technical reference for cementing in other similar complex situations.