古深3井非目的层井段气体钻井设计与实践

Design and Practice of Gas Drilling in Non-target Zone Section of Well Gushen-3

古深3井是部署在松辽盆地西部断陷区古龙断陷敖南凹陷的一口风险预探井,目的层为营城组,在3180～4460 m非目的层井段实施气体钻井,层位为泉一段～登一段,总进尺1208.72 m。通过地层出水预测,结合气体钻井的特点,对井身结构设计、钻具组合设计、钻头及参数优选以及注气排量设计等进行了优化设计,同时优化钻井工艺,采用气液转换,机械钻速达6.36 m/h,比邻井古深1井同层位常规钻井平均机械钻速1.40 m/h提高了4.54倍,缩短了钻进周期43.56天,提速效果明显。同时创造了气体钻井单只钻头进尺674.87 m和单只钻头使用时间101.88 h的新纪录。

Well Gushen - 3 is a risk wildcat well in Gulong faulted zone of the rift area in the western part of Songliao ba- sin, the target layer is Yingcheng group. The gas drilling was used in the non-target zone section of 3180 - 4460 m, that was Quantou formation - Denglouku formation, the total footage was 1208.72 m. By the effluent prediction and according to the features of gas drilling, optimizations were made to well structure design, BHA design, bits and parameters as well as gas injection rate; drilling by gas-liquid conversion, the mechanical drilling speed reached 6. 36 m/h, which was 4. 54 times increasing than the adjacent well Gushen 1 （average ROP of 1.40 m/h） ; and the drilling cycle was shortened 43.56 days. The new records of gas drilling were created that footage and service life reached 674. 87 m and 101.88 h with a sin- gle bit.