一种新型多元醇钻井液性能评价及应用

Performance Evaluation and Application of New Polyol and Polyol Water Base Drilling Fluid

新开发的多元醇为EO/PO共聚物 ,相对分子质量 30 0 0 ,无色液体 ,浊点 2 3℃。在室内性能评价中 ,这种多元醇在淡水、饱和盐水、7%KCl溶液中对页岩的抑制性 (页岩回收率 )良好 ;1.5 %多元醇在膨润土浆中的润滑性好于 3%白油 ;加入 3%多元醇的膨润土浆可耐 4%粘土和 1%水泥的污染 ,在 12 0℃滚动 16小时后性能变化不大 ;多元醇能与聚磺钻井液配伍。在塔里木依南 4井斜度变化大且易坦塌井段 ,使用由聚磺钻井液转化的多元醇钻井液钻进 ,井径扩大率有所减小 ,钻井液滤失量减小 ,摩阻系数减小 ,起下钻柱时摩阻减小 ,电测仪器起下顺利 ,在不加消泡剂情况下钻井液不起泡。

The newly developed polyol as water base drilling fluid additive is a EO/PO copolymer of M=3 000 and a colorless liquid with claud point 23℃. The laboratory evaluation shows that the inhibiting property of the polyol is good in fresh and saturated salt water and in 7% KCl solution; the lubricity of the betonite mud treated by 1.5% polyol is better than that by 3% white oil; the bentonite mud treated by 5% polyol is tolerant to 4% clay and 1% cement and has its performance properties less changed after rolling at 120℃ in 16 hrs; the polyol is compatible well with polymer/sulfomethylated phenolic resin fluid system. In drilling through a long easily collapsing section of varying direction in well YN-4 at Tarim, a polyol fluid converted from a polymer/sulfomethyl phenolic resin fluid is used successfully and following results are obtained: decrease in borehole enlargement, lowering of water losses, both API and HTHP, and of frictional resistancy, less resistancy to pipe trip, freely lowering of electric logging tool, and no foam formation without defoamer added.