致密油储层试油分布式光纤传感监测技术

Monitoring technique involving distributed optical fiber sensor for well testing in tight oil reservoirs

分布式光纤传感监测技术利用光纤系统配合模块化井下工具,实时监测井筒中气/液体运动及井筒和地层之间的物质交换。该项技术可用于监测生产层段的温差、流体性质变化,计算单段、单簇的产能贡献率等参数,对水平井压后分段产能进行评价,为压裂参数设计及后期作业等措施提供参考依据。松辽盆地A井采用蓄能式体积压裂工艺进行了改造,应用连续油管式光纤测试技术对该井在不同生产制度下的温差变化进行监测。通过拟合模拟生产曲线与实测生产曲线,获得各产层对压裂后产能贡献率。监测分析发现,泉四段的57小层的第六、七、八段为主力生产层,产量贡献占全井的64%~68%;第九、十段在4 mm油嘴工作制度下表现出高产量,但含水率极高,可实施堵水作业以降低含水率。该技术在国内油气田监测中应用较少,应加大在致密油储层改造、储气库和高压气井中的推广力度。

The monitoring technique involving distributed optical fiber sensor can monitor the gas/liquid movements in wellbore and the mass exchange between wellbore and formation in real time by using the optical systems together with modularized downhole tools.The technique can be deployed to monitor temperature differences and fluid properties in producing intervals,calculate the contribution to deliverability for individual intervals and clusters,and evaluate the deliverability of horizontal wells after staged fracturing,so as to provide reliable data for fracturing parameter design and subsequent operations.The CT-conveyed optical fiber monitoring technique was used to monitor the temperature differences under different production systems in Well A of the Songliao Basin,which was fractured by energy-storage volume fracturing.Through fitting simulated production curves and actual production curves,the contributions of pay zones to post-fracturing deliverability were determined.Monitoring results show that Interval 6,7 and 8 in Sublayer 57 of Quan-4 Member are major pay zones,which contribute 64%– 68% of the total well deliverability,and Intervals 9 and 10 reveal high productivity when producing 4 mm nozzle,but with high water cut.Water-plugging should be performed to reduce the water cut in Intervals 9 and 10.The proposed technique is worthy of popularization in stimulation of tight oil reservoirs,gas storages and high-pressure gas wells.