延长油田罗庞塬区水平井钻井液防塌技术研究

Research on Anti-collapse Technology of Horizontal Well Drilling Fluid in Luopangyuan Block of Yanchang Oilfield

延长油田罗庞塬区块部分层段由于泥页岩、碳质泥岩和油页岩发育突出,在钻井施工中常出现定向托压、掉块普遍和地层垮塌严重等现象,针对这些技术难题进行了该区块钻井液体系研究,确定4%KCl、5%聚合醇和0.6%~0.8%SI-150作为抑制性防塌处理剂主体防塌,选择1%氧化沥青、3%超细碳酸钙(1%2000目+2%3000目)和1%弹性石墨作为封堵性防塌处理剂协助防塌,形成了适合延长油田罗庞塬区块防塌钻井液体系。该钻井液体系封堵性和抑制性良好,页岩滚动回收率保持在93%以上,极压润滑系数控制在0.07以下。该钻井液体系在罗平16井和蒲平48井2口水平井成功进行了现场应用,取得了良好效果。

Due to the development of mud shale, carbonaceous mudstone and oil shale in some sections of Luopangyuan block in Yanchang oilfield, the directional backpressure, block falling and serious strata collapse often occur in the drilling construction, the research on anti-collapse drilling fluid system for this block is carried out. The results show that 4% KC1, 5% polyalcohol and 0. 6% -0. 8% SI - 150 can be used as inhibitory anti-collapsing agent, and 1% oxidized asphalt, 3% superfine calcium carbonate （1% 2000 mesh ＋ 2% 3000 mesh） and 1% elastic graphite as plugging anti-collapse treat- ment agent to help prevent collapse, together forming an anti-collapse drilling fluid system suitable for Luopangyuan block in Yanchang oilfield. With the good sealing property and inhibition of this drilling fluid system, the shale rolling recovery was remained at over 93%, extreme pressure lubrication coefficient controlled less than 0. 07. The drilling fluid system has been successfully applied in 2 horizontal wells of Luoping 16th well and Puping 48th well with good results.