高温高压和高含硫气井固井水泥浆设计

Cement Slurry Design for HTHP Gas Wells with Rich H_2S

川东高温、高压和高含硫气井具有多压力系统且密度安全窗口窄、裂缝发育等特点,导致固井期间又漏又喷,固井后期出现窜槽、微间隙,大大增加了固井水泥浆的设计难度。介绍了"三高"气井固井水泥浆设计时应注意的问题,包括平衡压力设计、材料选择、干混监控、复核实验、组织协调以及某井水泥浆设计的教训与经验。

HTHP gas wells with rich H2S, which are similar to ones in eastern Sichuan Basin, are featured by various pressure systems, a little scale of safety window for gas density, and developed fracture. So, lost circulation and blowout may occur during cementing whereas channeling and micro gap may occur during later cementing, further to increase a difficulty to design cement slurry. In this paper, some problems which should be paid attention to in this design are firstly presented, for example, balanced-pressure design, chemicals selection, solid chemical, fluid and compound monitoring, rechecking experiment and organization coordination. Some design experience from one well is obtained; meanwhile it can provide guidance for new cementing design.