泡沫水泥浆固井工艺技术

CEMENTING TECHNOLOGY OF FOAM CEMENT SLURRY

花土沟油田是青海石油管理局 1个开发多年的主力油田 ,井深为 130 0m左右 ,现在所钻的井多为调整井 ,地层压力系数很低 ,仅为 0 .6～ 0 .8,油层分布特点是薄、散、多 ,且上部 80～ 15 0m还有浅气层 ,油层固井要求全井封固 ,水泥返至地面。该区块原来油层固井合格率为 92 % ,优质率仅为 48% ,固井质量严重影响了该油田的产能建设和合理开发。为了解决这一固井难题 ,对泡沫水泥浆固井技术进行了研究 ,并对 5口井进行了油层封固 ,固井施工顺利 ,未发现漏失现象 ,经声幅测井证实 ,5口井水泥均返至地面 ,油层固井优质率高达 10 0 %。实践证明 :这种新型的低密度化学泡沫水泥解决了低压易漏井、长封固段井和稠油热采井的固井难题 ,提高了固井质量 ,缩短了建井周期 ,节约了成本 ,经济效益十分显著。

Huatugou Oilfield has been developed for years, thus the formation pressure coefficient is extremely low, only of 0.6～0.8; moreover, shallow gas exists in the zone of 80～150m to the surface, therefore complete zonal isolation is required for the pay zone cementing, with cement top at the surface. Adjustment wells are drilled for further development, and most of the wells are around 1300m. Cementing quality was poor in this area, and it severely limited the development of this Oilfield. To solve this problem, the foam slurry cementing technology was studied and used in the pay zone isolation of 5 wells. The cementing operation was smooth and no lost circulation was found, and acoustic amplitude logging proved that the cementing qualities were excellent.. This novel lightweight cement solves such problems as cementing the low pressured and lost circulation well, long interval isolation and heat production well; furthermore, it improves the cementing quality, shortens the well construction period and cuts down the cost.