The Study On Lost Circulation Controlling Technique In Kazakhstan North Buzachi Oilfield

Lost circulation result in very big bane which restricts development of superior quality, high efficiency safe drilling. It is important for us to know how to prevent lost circulation and lower its frequency of occurrence. Demand for having continuous increasing the technique of preventing lost circulation and lower the drilling cost can adapt the need of the development in oil field. The article make a summary about lost circulation controlling technique research and actuality of development both domastic and abroad, then introduce how to prevent and deal with it after lost circulation. It includes the well wall rock fracture mechanism while drilling and it also provided the methods of equivalent circulating density through the formation stress models. Making use of caculation method by well logging curve data. Draw a conclusion how to prevent and handle lost circulation by using optimum casing program, drilling assembly and technical measure including new type of lost circulation material and the drilling technique of the formation pressure releasing and gets a good result.