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.