川东北复杂压力体系气井固井技术

川东北地区普光、河坝、元坝等区块的海相天然气藏勘探取得了重大突破，该地区目的层埋藏深，地层压力和温度高，H2S和CO2含量高，属“三高”气田。陆相和海相地层有多套压力系统，长封固段和小间隙是固井工艺面临的主要挑战，H2S和CO2对气井长期安全造成威胁。2006年以前川东北探井的技术套管和生产套管固井的一次合格率仅为80 %和72 %。通过研究应用胶乳防腐防气窜水泥浆体系，紧密堆积高密度防气窜水泥浆体系，正注反挤工艺和分段压稳模型设计环空液柱结构等体系和工艺技术，固井质量较2006年前有大幅度提高。普光气田

Cementing technology of gas wells with complex pressure on Northwest Sichuan

Great achievements had been made on gas exploration on northwest Sichuan province with successful discovery of gas structures such as Puguang and Heba and Yuanba etc. High temperature and hiang pressure and high H2S are typical character of those gas fields. There have several sets of strata pressure systems in land sediment and sea sediment stratums, and the most challenge of cementing job is long cementing section and thin casing annular, and high concentration of H2S and CO2 in gas reservoir will threaten the safety of gas wells. The fair rate of bond quality of intermediate casing cementing and production casing cementing is only 80 % and 72 % separately. By researching and applying Latex anti-corrosion and anti-gas igration slurry and tightly packed heavy anti-gas migration slurry along with techniques such as pump directly with injection opposite for intermediate casing cementing and sector-by-sector surcharging model for designing annular liquid column structure. The bond quality increase highly comparing those before 2006. Referring to Puguang gas field the fair bond is 100 % and good bond 90 %, which has provided safeguard for the gas field putting into production.