煤层气井空气造穴工艺的实践与认识

空气造穴完井是煤层气井所特有的一种行之有效的完井方式,目前在国内外一些地区已经得到有效应用,并取得一定效果,尤其是在美国的圣胡安盆地。但是这种技术也有其局限性,对地质和储层条件要求高,所以在采用该工艺时,不可完全照搬。我国的山西寿阳地区的煤层厚度较大,含气量较高,具有较好的渗透率,且完井深度较浅,使该工艺得以成功实施;而沈北地区虽然煤层较厚,但渗透率低,并受到煤层顶板油页岩物性的影响,空气造穴作业后的返出物体中有大量的顶板油页岩,说明该井的顶板坍塌很严重,这对完井后的排采工作带来极大的隐患和风险,因此,需考虑区内的特殊储层地质条件,对该项技术进行深入的研究,从而提出改进方法。

Study and Practice of Air-cavitation Technology for CBM Wells

Air-cavitation well completion technology is one kind of workable completion manners in CBM exploration.Nowadays,this technology has been successfully put into practice in some areas in China and abroad,especially in the San Juan Basin in America.On the other hand,this technology also has some limits,especially requiring good geological reservoir conditions.So it can＇t be applied in all coalmines in China.When this technology is used,we can＇t completely copy the experience from other countries.For example,the coal beds in Shouyang area of Shanxi Province are rather thick,with higher gas content and better permeability.Also,due to rather shallow well completion depth,it is favorable to successfully put it into practice.However,although the coal beds in Shenbei area are thicker than those in San Juan Basin,while permeability is rather low in this area.Therefore,considering the special geological considerations of the reservoir,further studies are supposed to carry out to improve this technology.