A Block Formation Drilling Resistance Strength And Borehole Wall Stability Study

A gas reservoir is the key of the developed in the recent years,the effective development of gas reservoir is to achieve the goal of construction of "twelfth five-year" capacity.The gas reservoir buried deep about 3400 meters,belongs to low pressure tight gas reservoir,the drilling speed is slow,single bit penetration,less to the borehole wall stability,drilling construction to bring very great challenge.For the drilling speed and safety drilling,carried out the block drillability,abrasive and borehole wall stability prediction research.Based on the above purpose,carried out:(1)the rock hardness,plasticity coefficient,drillability,abrasive test;(2)the formation drilling resistance characteristic parameters was established by mathematical statistics and correlation model of logging data,and the block 3 Wells in the drilling resistance profile prediction;(3)for directional well sidewall stability problem,from mechanics methods to analyze the stress distribution of the borehole wall,directional borehole wall stability mechanical model is established.Model takes into account the specific formation rock strength parameters,the in-situ stress state and borehole space position,improve the calculation precision of the formation collapse pressure and fracture pressure.For subsequent drilling speed and the production of the safety drilling construction,provides the basis.