CQ-IGS水平井一体化地质导向技术——以在长宁-威远国家级页岩气示范区的应用为例

Integrated geosteering technology for CQ-IGS horizontal wells and its application in the Changning-Weiyuan National Shale Gas Demonstration Area

地质导向技术是页岩气水平井钻进的核心技术之一,但是仅根据单一随钻测量参数的常规地质导向方法已无法满足页岩气快速商业化开发的需要。为了精准控制水平井轨迹,采用三维地震数据体高分辨率处理技术,结合自主研发的水平井一体化地质导向软件平台,建立精细三维地质导向模型,通过该软件平台对三维地震、随钻测井、综合录井一体化处理解释,应用岩屑识别和成分分析技术,实现了对水平井轨迹的精确控制,形成了水平井一体化地质导向技术。2011-2018年在四川盆地长宁-威远国家级页岩气示范区187口井的应用结果表明,采用该技术后每口水平井水平段钻进时间从原来的35 d缩短为2018年的25 d;平均单井靶体钻遇率达到96.7%,最优地质甜点的平均单井钻遇率由2014年的35.3%提高到2018年的91.0%;威远页岩气区块单井测试日产量从原来平均每口井11.5×10^4m^3提高到15.5×10^4m^3;长宁页岩气区块单井测试日产量从原来平均每口井14.0×10^4m^3提高到18.5×10^4 m^3。结论认为,该技术合理优化了钻井轨迹、缩短了钻井周期、节约了钻井成本,显著地提高了储层的钻遇率和单井产量。

Geosteering technique is one of the core technologies in the drilling of shale-gas horizontal wells,but the conventional method only based on logging while drilling data cannot meet the needs of rapid commercial development of shale gas.To control the trajectory of horizontal wells accurately,this paper established a fine 3 D geosteering model using the high-resolution 3 D seismic data volume processing technique,combined with the independently developed Chuanqing-Integrated Geo-Steering(CQ-IGS)software platform.In this software platform,integrated processing and interpretation was carried out on 3 D seismic,logging while drilling and compound mud logging.The horizontal well trajectory was controlled accurately by means of cuttings identification and component analysis technique.In this way,a horizontal well integrated geosteering technique was developed.Its application in 187 wells in the Changning-Weiyuan National Shale Gas Demonstration Area of the Sichuan Basin during 2011-2018 shows that the drilling time of the horizontal section of each horizontal well is shortened from 35 d to 25 d in 2018;the average target drilling rate per well is 96.7%;the average optimal geological sweet spot drilling rate per well is increased from 35.3%in 2014 to 91.0%in 2018;the average daily production per well is increased from 11.5×10^4 m^3 to 15.5×10^4 m^3 in the Weiyuan Shale Gas Block and from 14.0×10^4 m^3 to 18.5×10^4 m^3 in the Changning Shale Gas Block.In conclusion,this technique reasonably optimizes drilling trajectory,shortens drilling cycle,reduces drilling cost,and remarkably improves target-encountered drilling rate and single-well production rate.