热压裂液技术研究及应用

Study on hot fracturing fluid technology and its application

辽河油田的高凝油产量占油田总产量的60％以上。由于高凝油的凝固点、含蜡量、胶质沥青质含量高,在油层改造过程中压裂液对储层产生的冷伤害,使蜡、胶质沥青质不断从原油中析出,沉积在油流孔道中,造成出油孔道被堵塞,严重影响压裂增产效果。研制应用了热压裂液工艺技术,使压裂液入井温度高于原油析蜡温度,降低了压裂液对地层产生的冷伤害。通过试验优选出了热压裂液配方。基液:(1.4％-1.8％)浓缩液体瓜胶+0.2％FR-CL/LH-Ⅰ破乳助排剂+0.05％FR-BA/LH-Ⅰ杀菌剂+0.05％CO-DFO/LH-Ⅱ消泡剂+(0.02％-0.03％)NaOH;交联液:(10％-15％)高温延迟交联剂+(1％-2％)胶囊破胶剂;交联比为100:(2-3)。经在稠油区块16口井应用表明,热压裂液工艺技术对高凝油油藏的压裂效果较好,平均单井增产原油12.75 t/d,取得了很好的经济效益。

Over 60% of the oil production is high viscous crude in Liaohe Oilfield, and the content of wax and gelling asphalt is also high. The precipitation of wax and gelling asphalt during fracturing causes the blocking of throats and this seriously impacts the effect of fracturing stimulation. The hot fracturing fluid technology is developed and applied, by raising the fracturing fluid temperature so that its temperature is higher than the wax precipitation point, and this minimizes the formation damage because of cold fracturing fluid. The composition of the hot fracturing fluid is optimized, which consists of base fluid and cross-linking fluid. The base fluid is made up of 1. 4%-1. 8% of concentrated fluid guar gum, 0. 2% of FR-Cl/LH- I demulsifier, 0. 05% of bactericidal agent and defoaming agent, and 0. 02%-0. 03% of pH value adjusting agent. The cross-linking fluid is consisted of 10%-15%of high temperature delayed crosslinker and 1%-2% of gel breaker, the cross-linking ratio is 100/(2-3). This technology has been used in 16 wells for viscous crude reservoir fracturing, and a remarkable production rate improvement of 12. 75 t/d has been achieved.