组合式滑套分段压裂管柱研究及现场应用

Development and field application of combined sliding sleeve staged fracturing string

为了实现无限制、大排量体积压裂和复杂层段生产控制的高效改造和开采目标,提出了一种在下部产层稳定层段安放投球滑套、在上部需要生产控制层段安放开关滑套组合应用的分段压裂技术。施工中,依次投球逐级打开并压裂投球滑套段,然后投入隔离球封隔下部已压裂段;再下入连续油管开关工具,根据地层需要有选择性地开关各开关滑套层段,实现个性化压裂。后期开采阶段,如果开关滑套层段出现问题,可再次下入连续油管开关管柱关闭问题段,实现其他层段的正常开采。组合式滑套分段压裂技术在苏75-60-34H井进行了3段开关滑套和7段投球滑套整体10段现场应用,施工排量达到9.2 m^3/min,施工压力达到72 MPa,日产气20×10~4 m^3,施工效果超过预期,为复杂油气藏各段一对一压裂和生产控制提供技术借鉴。

In order to realize high-effciency stimulation and production of high-displacement unrestricted volume fracturing and complex interval production control, a combined staged fracturing technology was developed to set the ball-actuated sliding sleeve at lower stable intervals and the switch sliding sleeve at upper production control intervals. First, the balls are dropped to open ball-actuated sliding sleeves successively and the corresponding intervals are fractured. Then, the separating spheres are thrown to isolate the intervals that have been fractured in the lower part. Finally, switch tools of coiled tubing are run in hole to conduct specifc fracturing by switching on or off each switch sliding sleeve selectively according to the formation conditions. If any problem occurs in the interval with switch sliding sleeve in the process of later exploitation, another switch string of coiled tubing should be run in hole to isolate the interval in problem while the other intervals are kept in normal production. This combined sliding sleeve staged fracturing technology was applied in Well Su 75-60-34H with three switch sliding sleeve intervals and seven ball-actuated sliding sleeve intervals. The fracturing effect is better than the expectation with displacement rate of 9.2 m3/min, fracturing pressure of 72 MPa and daily gas production 20×104 m3. It provides the technical reference for the one-to-one fracturing and production control of each interval in complex oil and gas reservoirs.