浅层气处理技术在哈萨克斯坦蒙泰克地区M-3A井中的应用

哈萨克斯坦国蒙泰克地区普遍存在浅层气,该地区M-3井因浅层气井喷导致勘探失败。为了尽快开采早白垩世和侏罗纪油层,在M-3井相邻位置重新部署M-3A井,充分利用国内成熟的浅层气处理技术,保证成功完钻。浅层气在二开中出现,对浅层气的预防处理是该井勘探成败的关键。开钻前需要根据当地地质特征设计出合适的钻井液,预防二开浅层气可能造成的井喷与井漏,同时制定出一套完整的浅层气处理预案。钻探落实浅层气出现于293 m深度处。钻遇浅层气时,钻时减小、循环钻井液气测值增大,出口钻井液密度减小,通过停钻循环、增加钻井液密度等措施成功控制了浅层气。在钻井过程中采取短起下等操作疏通井眼,通过倒划眼操作解决了起钻过程中出现的拔活塞现象,有效控制了浅层气。为同类油井的施工提供了经验。

Shallow gas controlled technology used in the well M-3A Mynteke area of Kazakstan

The shallow gas was widely consisted in the Mynteke area of Atyrau Oilfield,Kazakstan,and very difficult to control and deal with due to it's very soft surface formation.And the well No.M-3 was failed to drill and explore because of the blowout.But the well No.M-3A which was reset out near the well No.M-3 was aimed to prove up the reservoirs in the Cretaceous and Jurassic.And expected to drill out to the TD depending on the Chinese ripe technology and plenty of experience in Shallow gas controlled.The shallow gas will be encountered while drilling the second section after set the surface casing,and it was the key point to control and deal with the shallow gas in the drill operation.At the first,designing the proper mud weight according to the geologic data to overbalance the formation pressure.And second,setting down the emergency well control procedures to prevent the blowout if happened.As the fact,the shallow gas was encountered while drilling to 293 m.The drilling crew found that the bit break down,return mud weight decrease,and LEL increase,and stopped drilling immediately to increase the mud weight to kill the well,and then circulate out the gas influx in mud.Conditioned the open hole by wipe trip to avoid the surge pressure while tripping.The shallow gas was killed successfully and the well was completed smoothly.