深层页岩气钻井技术难点与对策

TECHNICAL DIFFICULTIES AND COUNTERMEASURES OF DEEP SHALE GAS DRILLING

深层页岩气埋藏深,岩石强度、温度和压力高,钻进中钻遇层系多,机械钻速低,周期长,成本高,制约了其经济有效开发。针对该问题,对国内外深层页岩气钻井技术进行了对比分析,总结了川东南深层页岩气地质特征和钻井面临的技术难点,结合前期深层页岩气钻井实践,从井身结构优化、钻井参数优化、提速工具优选、轨迹控制、控压降密度、高密度油基钻井液和套管柱设计等方面提出了深层页岩气钻井技术对策。

Deep burial depth,high rock strength,high temperature,high pressure and multiple formation systems leads shale gas drilling to low ROP,long drilling cycle and high drilling cost,which restricts the economic and effective development of the deep shale gas.In view of this problem,comparative analysis of the deep shale gas drilling technology at home and abroad is carried out,and the geological characteristics and the technical difficulties faced by drilling deep shale gas in southeast Sichuan is summarized.Technical countermeasures for deep shale gas drilling are put forward in aspects of casing program optimization,drilling parameters optimization,ROP-improving tool optimization,trajectory control,pressure control,high density oil-based drilling fluid and casing string design,etc.