Considering the strata characteristics of Hulun Lake,new piston sampling drilling tool and press-fitting sampling drilling tool were developed.

Based on lessons and experiences learned from the previous countermeasures dealing with drilling accidents, this study put forward a new type of safety joint while drilling which could treat sticking very well, while introducing in detail what the problem of sticking was like and the superiority and strength of this new safety joint.

However, there have been seven sticking accidents happened during the mid stage of development, which has great effect on the exploration and development of the region.

The sticking of the downhole string happened occasionally because great quantity of packers and other tools with slips are used.

Based on groping for and summarization of the processing method drilling failure,and according to the characteristic of drill pipe sticking,this paper proposed a new design for drilling safety joint,which can commendably deal with drill pipe sticking accidents.

In consideration of drill pipe sticking in production of limestone section, it is considered that the sticking is caused by uncleaning wellbore, thus the concept of releasing the sticking by acidizing is proposed.

These high pressures, combined with depleted zones, frequently induced differential pipe sticking.

Tech of Unstuck of Perforated Gun in Horizontal Well of Moxi Gas Field;

Soak diesel and releasing stuck agents were employed in site but no any effect.

When constituting releasing stuck program, we must analyze the stuck reasons and confirm the depth of the free point at first, as the essential prerequisite and basis.