低荧光强封堵型防塌剂LFT的研究与应用

Research and Application of Low Fluorescence Shale Inhibitor LFT

研制出了可替代磺化沥青的以聚乙烯副产物和有机铝为主要作用物质的低荧光强封堵型防塌剂LFT。介绍了防塌剂LFT的合成和性能评价。结果表明,合成出的防塌剂LFT在其加量不大于2%时对钻井液流变性无影响;加量为0.2%时即可有效抑制黏土的水化膨胀,同时又可在地层温度和压力作用下挤入井壁微裂缝中,与泥饼一起有效封堵地层,LFT在90℃下对人造岩心的封堵率在90%以上。在白33侧井和桥81-2井的现场试验表明,防塌剂LFT的封堵效果好,井径规则、扩大率小,而且无荧光,不影响气测录井。

A new low-fluorescence shale inhibitor LFT is developed using the byproducts of polyethylene, and organo-aluminium. This product can be used as a substitute for sulfonated asphalt. In this paper the synthesis and the evaluation of LFT are introduced. The evaluating results showed that when the concentration of LFT is less than 2.0% it has no effects on mud rheology. LFT can effectively inhibit swelling clays at a concentration of only 0.2%. In downhole conditions (HTHP), LFT, like sulfonated asphalt, can be squeezed into the formation to seal the micro fractures in the formation. At 90 ℃, more than 90% of pores in the artificial cores can be sealed off. The application of LFT in wells Bai33 and Qiao81-2 showed that this product can effectively seal the micro-fractures in the formation, and a near gauge hole can be obtained. Moreover, LFT has little, if any, effects on well logging.