
Cementing technology of gas wells with complex pressure on Northwest Sichuan
Zhou Shiming、Zeng Yijin
Strategic Study of CAE ›› 2010, Vol. 12 ›› Issue (10) : 50-55.
Cementing technology of gas wells with complex pressure on Northwest Sichuan
Zhou Shiming、Zeng Yijin
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.
complex strata pressure / thin annular / gas migration / pretermission / latex / sector-by-sector surcharging model
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