铝络合物钾盐强抑制性钻井液的应用

Field application of aluminium compound-potassium chloride drilling fluid

东濮凹陷兰聊断层下降盘白庙、前梨园、桥口等区块 ,从沙一段下部到沙二段有大段地层含有蒙脱石、伊利石及较多的伊蒙混层 ;沙三段为含伊利石的硬脆页岩 ,钻井液滤液易沿层理面的微裂缝渗入地层 ,引起井壁剥蚀垮塌。常规的聚磺钾盐钻井液有时不能有效稳定井壁 ,易引发井下复杂情况 ,钻井时效低 ,因此引入了新型抑制剂有机铝络合物LWJ 1 ,组成了铝络合物 钾盐钻井液。现场应用表明 :该钻井液抑制性强 ,防塌效果好 ,井径规则 ,与同区块使用聚磺钾盐钻井液的井相比 ,平均井径扩大率低 1 1 .3% ,钻井速度大大提高 ;膨润土容量限高 ,为 5 5g/L ,对流变性能影响小 ,钻井液性能稳定 ;抗高温能力强 。

In some blocks of Dongpu sag in Zhongyuan oilfield, montmorillonite and illite layers and interlayer exist sections Sha 1 and Sha 2, and the Sha 3 section consists of hard and fragile shale. As the filetrate can invade along the mic fractures of the stratification, sloughing and collapsing often occur. Although polymer potassium chloride system was used for holebore stabilization, holebore sloughing and collapsing frequently take place,resulting in lots of downhole troubles. A novel inhibitor organic aluminium compound LWJ 1 was used to prepare aluminium compound potassium chloride drilling fluid. Field application displayed that the drilling fluid system has high inhibition and good sloughing control ability. Comparing with the wells using polysulfonated potassium drilling fluid in the same block, average holebore enlargement rate was reduced by 11.3%; the good rheology, stability and high temperature tolerance were maintained easily when bentonite content was 55g/L.