巴喀油田固井工艺技术研究与应用

RESEARCH AND APPLICATION OF CEMENTING TECHNOLOGY IN BAKE OILFIELD

吐哈巴喀油田地层压力低、易垮塌、井底温度低，固井时易诱发井漏，污染油气层；水泥凝固时间长，强度发展慢；候凝时加不上回压，固井后管外冒油冒气。经室内试验，优选出低密度导浆、缓凝水泥浆和速凝水泥浆的三凝水泥浆配方体系，并采取了相应的措施，经12井次试验，未发生井漏、憋泵、管外冒油气现象。技术套管固井优质率83．3％，油层套管固井优质率100％，分别比试验前提高了47．7和48．8个百分点，不仅提高了固井质量，更重要的是防止了产层的污染。

Bake oilfield of Tuha has a low formation pressure and bottom hole temperature, its formation is easy to collapse. So lost circulation easily occurred during cementing to pollute oil/gas formation; And back pressure can not be applied when cement solidifies so that oil/gas emits outside casing after cementing. After laboratory experiment, the formulation system of lightweight conduct cement slurry, retarded cement and accelerated cement were optimized and corresponding measures were taken. No lost circulation, large flow resistance and oil/gas emitting outside casing occurred after experiment in 12 wells. The high grade rate for intermediate casing is 83.3%,for production casing is 100 %, increased 47. 7% and 48. 8% compared to pre - experiment respectively. Not only was cementing qualityimproved, but more important, prevented payzone from belng polluted,