涪陵平桥与江东区块页岩气水平井优快钻井技术

涪陵地区平桥与江东区块页岩气水平井钻井过程中经常出现井下故障，导致机械钻速低、钻井周期长，为此根据钻遇地层的特点，对导管和技术套管下深进行了优化，形成了双导管井身结构；根据页岩气水平井的特点，将井眼轨道优化为渐增式变曲率井眼轨道；根据不同井段对井身质量的要求，研究形成了高陡构造直井段及微增斜段井眼轨迹控制技术；根据不同井段钻遇地层的特点，通过分析钻井速度与钻进方式的关系，优选了钻井方式；针对钻遇地层的岩性、可钻性和研磨性对钻头性能的要求，研制了抗冲击牙轮钻头、斧形齿PDC钻头及混合钻头；优选了?285.8 mm低速大扭矩螺杆、?171.5 mm全金属水力振荡器等提速工具；为解决钻井过程中的漏失，选用了BT-100低密度强抑制钻井液和油基胶凝堵漏材料。通过上述研究，形成了适用于平桥与江东区块页岩气水平井的优快钻井技术。截至目前，该钻井技术已在涪陵地区平桥与江东区块应用了32口井，平均钻井周期由应用优快钻井技术前的128.00 d缩短至76.25 d，提速效果好，为平桥与江东区块钻井提速提供了技术支撑。 

Optimized and Fast Drilling Technology for Horizontal Shale Gas Wells in Pingqiao and Jiangdong Blocks of Fuling Area

Downhole problems and failures are often encountered while drilling the shale gas horizontal wells in Pingqiao and Jiangdong blocks of Fuling Area,which result in low ROP and long drilling cycles.Consequently,we studied the latest technologies for optimizing drilling and increasing the rate of penetration in shale gas wells.We focused first on conductive and technical casing,which could be optimized to the point that it turned into a double conductor program.We could also optimize the wellbore trajectory using incrementally variable curvature.In addition,the trajectory control technology of vertical well section and small build-up section was developed for drilling high-steep structures according to the requirement of well quality on different well sections.The relationship between ROP and drilling method is analyzed and the drilling methods was optimized according to the characteristics of different formations in different sections.Furthermore anti-shock roller bit,axe tooth PDC bit,and hybrid drill bit are studied and developed to meet requirement from bit performance on lithology,drillability,and abrasiveness of drilled formation.The ?285.8 mm low-speed and high-torque motor and ?171.5 mm all-metal hydraulic oscillator are optimized for ROP enhancment.BT-100 low-density and high inhibiting drilling fluid and oil-based gel plugging materials are selected to solve the problem of circulation loss.Hence,the guidelines for optimized and fast directional drilling technology for shale gas wells in Pingqiao and Jiangdong blocks could be established through those studies.The technology was applied in 32 wells in Pingqiao and Jiangdong blocks of Fuling Area.By using this technology,the average drilling cycle was decreased from the previous 128.00 days to 76.25 days with excellent ROP increasing effect,which provided reference to enhance ROP in Pingqiao and Jiangdong blocks well drilling.