聚胺微泡沫钻井液及其作用机理

Polyamine Micro Foam Drilling Fluid

针对孔隙或裂缝性低压地层井漏、井塌及油气层损害等多种技术难题,以聚胺为水化抑制剂,结合微泡沫钻井液特点,构建了聚胺微泡沫钻井液体系。通过调整搅拌速度、优选加重剂、增黏剂加量及p H值等手段,使聚胺微泡沫钻井液密度在0.43~1.15 g/cm3之间可调。研制的聚胺微泡沫钻井液体系的抗温达120℃,可抗12%氯化钠、20%海水、12%劣质土、21%柴油污染,具有较好的防漏堵漏性能及储层保护效果。聚胺微泡沫钻井液兼有聚胺的表面水化、渗透水化抑制作用,加之较低的表面张力、活度,具有屏蔽暂堵性,在井壁上形成半透膜,可起到良好的防止井壁坍塌和保护油气层作用。

A polyamine micro foam drilling fluid was formulated for use in drilling porous or fractured low pressure formations where mud losses had frequently occurred,and in combating well collapse and reservoir damage.The density of the polyamine micro foam mud can be controlled within 0.43 g/cm^3-1.15 g/cm^3 by adjusting mixing speed,optimizing the use of weighting additives and viscosifiers,and adjusting pH of the mud.The micro foam mud can be used in these conditions such as high temperature(120℃),12%NaCl,12%clay of poor quality,or 21%diesel oil contamination.Polyamine used in the mud can inhibit surface hydration and osmotic hydration,and the ability of polyamine to reduce surface tension and to form semi-permeable membrane on the surface of borehole wall makes it superior in borehole instability control and reservoir protection.