二连油田水平井钻井液技术

二连油田砂岩油层薄,产状变化较大,水平井段钻进存在携砂困难、摩阻控制难度大、易产生岩屑床等技术难点,优选出了有机黑色正电胶聚合物混油钻井液,以期利用其较强的抑制性、悬浮携屑能力、稳定性和低摩阻的特点,达到实现安全快速钻井的目的。现场应用结果表明:该钻井液携砂效果好,抑制能力和润滑防卡性能强,钻井液性能稳定,维护处理简单;蒙平1、林4平1和林4平2三口水平井都没有发生与钻井液有关的井下复杂事故;林4平2井地层产状变化较大,整个水平段为波浪型,但水平段井身质量和固井质量均达到了设计要求;蒙平1井钻井周期为35d,同时伴有水侵发生,施工中未出现垮塌现象,表明该钻井液能满足二连油田水平钻井施工的需要。

Study and Application of Horizontal Drilling Fluids in Erlian Oilfield

The hydrocarbon reservoirs in Erlian Oilfield are mostly sandstone. The reservoir formations are thin, and diverse in attitudes. Solids "sag"in horizontal wells and the friction between drill pipes and borehole wall impose difficulties on drilling operation. An organic black MMH-polymer drilling fluid, mixed with oil, was developed to deal with the said problems. Field operation showed that the MMH drilling fluid performed much better in terms of solids carrying capacity, shale inhibition, lubricity, rheological stability and mud maintenance. No mud-related downhole problems had occurred in well Mengping-1, well Lin-4-ping-1 and Lin-4-ping-2, which were drilled with the MMH drilling fluid. Well Lin-4-ping-2 had a diverse attitude, and the well path waves up and down along the horizontal section, while the well bore quality and cement job quality all met the design requirement. Well Mengping-1 was drilled in 35 days with water kick, while no shale formation sloughing occurred.