高内相逆乳化钻井液体系的室内研究

LABORATORY STUDY OF INVERT EMULSION DRILLING FLUID WITH HIGHER INTERNAL PHASE

为了有效降低油基钻井液的油相比例,研制了高内相逆乳化钻井液体系。该体系具有低油、低毒、低固相、较低成本的优异特性。该体系的配方为5^#白油＋30%CaCl2盐水＋HFGEL-120型有机土（w=1%）＋石灰（w=0.5%）＋脂肪胺类乳化剂（w=3.6%）＋自制酰胺类稳定剂（w=1%）,油水体积比为50∶50,钻井液的密度为1.20~1.85g/cm^3。室内性能评价结果表明：该高内相逆乳化钻井液体系性能良好,破乳电压为400~900V,抗温性达160℃,120~150℃高温高压滤失量≤10mL,流变性与传统逆乳化钻井液相当。进一步评价表明,该体系还具有良好的抗污染性、抑制性、储层保护性能。

To efficiently reduce the cost,a novel invert emulsion drilling fluid with higher internal phase has been invented.The new drilling fluid system has the distinct properties of less oil,less toxicity,less solid phase and lower cost.The effective formulation of the new invert emulsion drilling fluid is:5#white oil+ 25% CaCl2brine+ organoclay(1%)+lime(0.5%)+fatty amine type emulsifier(3.6%)+ amide type stabilizing agent(1%),oleaginous fluid to non-oleaginous fluid-ratio is 50/50,drilling fluid density is 1.20-1.85g/cm3.Evaluation results in laboratory test showed that the new drilling fluid had good performances with emulsion-breaking voltage of 400-900 V,resistance to high temperature of 160℃,HTHP filter loss≤10mL at 120-150℃,andrheology in line with traditional invert emulsion drilling fluid.Further experimental data showed that,this new mud system also perform well in anti-fouling,inhibiting shale expansion and protecting formation.