胶乳水泥固井技术在LG地区X井的应用

LG地区X井是一口开发井，属于大斜度定向深井，最大井斜为64.78°，完钻井深为6 990 m。该井127.0 mm尾管固井具有井底温度高、封固井段长、井斜大、间隙小、油气活跃、易漏失等难点，对固井水泥浆性能要求高，固井质量难以保证。针对上述固井难点，采用耐高温防气窜胶乳并结合新型聚合物缓凝剂，研发了一套适合高温长封固井段固井的胶乳防气窜水泥浆体系。实验和应用结果表明，该水泥浆流动性好、浆体稳定、滤失小、稠化时间易调、过渡时间短、顶部水泥强度发展快，综合性能良好。该套胶乳水泥浆体系结合相应的固井工艺措施，有效地解决了LG地区X井127.0 mm尾管固井过程中易出现的层间互窜、压漏地层、顶替效率差、顶部水泥浆超缓凝等固井难题。

Application of latex cementing in the well X at the LG area

The well X, one of an important exploratory well drilled in the LG structure by the PetroChina Southwest Oil & Gasfield Company, is a highly-deviated directional deep well with the maximum hole deviation of 64.78°and the total depth of 6990 m. The 127 mm-diameter liner cementing was challenged by many difficulties such as high bottom hole temperature, long cementing well section, large deviation, small clearance, active hydrocarbon movement, and lost circulation, etc., and so the quality of cement has to be highly required and the cementing quality is hard to be ensured. Therefore, a kind of gas-block latex cement slurry is developed adaptable for high-temperature and long well cementing section by adopting high-temperature resistant and gas-block latex integrated with a new polymer retarder. Laboratory and field test results show that this cement slurry has good advantages of good flow properties, steady thick liquid, less leakage, flexible thickening time, short transient time, quickly developed cement strength on the top liner and favorable overall performance. Combined with the corresponding cementing measures, this latex cement slurry has effectively solved many problems, such as interbed fluid flow, thief formation, low displacement efficiency, extremely slow set of top cement, which easily occurred in the process of cementing the well X by the 127 mm-diameter liner.