低密水泥浆在塔里木油田深井超深井中的应用

塔里木油田深井超深井漏失性地层的固井特点是，井深一般在5000m以上，油层套管固井环空间隙小，封固段长。为解决其固井问题，室内对低密度水泥浆进行了研究。经对减轻以及对低密度水泥配方的优选，得到2套低密度水泥浆配方，（1）中高温；低密度G级水泥；DiaceL－D为100：35－100：45；悬池剂D149，缓凝剂D081，降失水剂D158，减阻剂D80A,消泡剂D047；（2）高温；低密度G级水泥：DiaceL－D为100：35－100：45，悬浮剂OMEX－51S，缓凝剂HR－13L，降失水剂DiaceL－FL（液），消泡剂CDF－901或NF－4，实验表明，在不岂温度下，2套配方的沉降稳定性能都过关，且悬浮剂用量不大；温度由80℃上升到125℃时，不限水质配浆，水泥浆的稠化，流变和失水性能均好，现场2口井的ψ177.8mm尾管固井应用表明，该低密度水泥浆体秒适合塔里木油田深的窄环窄隙，长裸眼段固井。

Application of lightweight cement in the deep and super-deep wells in Tarim

Most wells are over 5000 m of depth in Tarirn, and the small annular space (within 20 mm) and long isolation section (1000-2800 m) causes serve cementing problems in the lost formation of deep and super-deep wells. Studies are carried out on lightweight cement to resolve these problems, and 2 sets of lightweight cement slurry formulations are determined. One for medium to high temperature environment, which is consisted of lightweight Grade G cement, lighting agent DiaceL-D of 100:35-100:45, suspension agent D149, retardant D081, filtrate reducer D158, drag reducer and defoaming agent. The other for high temperature environment, which is consisted of lightweight Grade G cement, lighting agent DiaceL-D of 100:35-100:45, suspension a-gent OMEX-51S, retardant HR-13L, filtrate reducer DiaceL-FL, drag reducer and defoaming agent. Tests show that the setting stability of both formulations can all meet the standard under different temperature, and better performances on slurry thickening, rheology and fluid loss are achieved. Cementing for the 177. 8 mm liner in 2 wells shows that this system is suitable for the small annular and long section isolation in Tarim.