川渝地区煤岩气水平井安全钻井技术探索——以JT1H井为例  

Safe drilling technologies for horizontal wells of coal-rock gas in Sichuan-Chongqing area and their application to JT1H well

作　　者：邓开建 敬婧 余星颖 卓云 张杰[1] 李高文 张钰 DENG Kaijian;JING Jing;YU Xingying;ZHUO Yun;ZHANG Jie;LI Gaowen;ZHANG Yu(Chuandong Drilling Company,CNPC Chuanqing Drilling Engineering Company Limited,Chongqing 401147,China;Chongqing Transportation Co.,Ltd.,CNPC Chuanqing Drilling Engineering Company Limited,Chongqing 401147,China)

机构地区：[1]中国石油川庆钻探工程有限公司川东钻探公司,重庆401147 [2]中国石油川庆钻探工程有限公司重庆运输总公司,重庆401147

出　　处：《天然气技术与经济》2024年第4期37-43,共7页Natural Gas Technology and Economy

摘　　要：为了安全有效开发四川盆地二叠系龙潭组煤岩气藏,保障川渝地区天然气能源供应的有效接替,需对龙潭组煤岩气井的开发难点进行研究,解决易发生的故障复杂等问题。为此以中国石油西南油气田公司重点探井JT1H井为研究对象,分析了该井面临的煤岩段裂缝发育、岩性复杂可钻性差、井眼轨迹变化大、钻井液性能控制困难等工程地质难点,从井眼轨迹、钻井液体系、钻井参数、精细操作防卡等方面开展复杂处理技术研究。研究结果表明:①采用五段式井眼轨迹设计,有效降低了狗腿度,满足了长度1000 m以上水平段安全钻井需要;②充分发挥地质工程一体化优势,做好煤层厚度、井下岩性、地层倾角等预测,为工程措施优化提供支撑,减少复杂;③建立煤岩气水平段钻压、转速、排量等关键钻井参数控制方法,减少煤层冲刷,降低地层垮塌程度;④应用地层岩性元素分析技术,及时发现高密度、高硬度的煤矸石,精细操作防卡。结论认为:①优选高效PDC钻头+旋转导向工具+螺杆复合钻井提速,保障了储层钻遇率,JT1H井水平段安全穿越二叠系龙潭组6套煤层,累计厚度为209 m,水平段长达1160 m;②优化钻井参数异常变化处理技术,充分使用好振动筛、一体机、离心机,探索形成煤灰机械消泡技术,减少了阻卡;③推广应用川渝地区煤岩水平段安全钻井技术,对于后续深入开展煤岩气开发技术研究具有指导意义。In order to safely and efficiently develop coal-rock gas reservoirs of the Permian Longtan Formation in Sichuan Basin and ensure the effective substitute of natural gas in Sichuan-Chongqing area,it is necessary to ascertain development difficulties in coal-rock gas wells with this formation as the target and to solve frequent accidents and complexities.Thus,taking JT1H well,a key exploration one deployed by PetroChina Southwest Oil&Gasfield Company as an objective,we discussed its sticking points in engineering and geology,including fractures developed within coal rocks,poor drillability resulted from complex lithology,large variation in wellbore trajectory,and inconvenient control on drilling-fluid performance.Then,complexity treatment was analyzed from four aspects of wellbore trajectory,drilling-fluid system,drilling parameters,and precise sticking prevention.Results show that(i)the five-stage trajectory is adopted,which reduces the dogleg degree with effect to satisfy the need of safe drilling for a horizontal interval over 1000 m long;(ii)giving full play to the geology-engineering integration and predicting coalbed thickness,downhole lithology and formation dip can help optimize engineering measures and lesson complexities;(iii)a method which may control the key drilling parameters in horizontal intervals like weight on bit(WOB),rotation speed and displacement is established to diminish coalbed scour and formation collapse;and(iv)lithologic elements are analyzed to detect high-density and high-hardness coal gangue in time and avoid sticking.In conclusion,the compound drilling technologies of efficient PDC bit+rotary steering tool+screw improve the rate of penetration and ensures the drilling rate.With the cumulative thickness of 219 m and the horizontal interval of 1160 m,there are 6 coalbeds of Longtan Formation safely drilled in JT1H well by virtue of these technologies.To deal with abnormality in drilling parameters,to adopt shale shaker,all-in-one machine and centrifuge with effect,and to develop coal-a

关 键 词：川渝地区 煤岩气 水平井 安全钻井 龙潭组 

分 类 号：TE28[石油与天然气工程—油气井工程]