自生热压裂液的研制及现场应用

PREPARATION AND FIELD USES OF HEAT-GENERATING HYDROFRACTURING FLUIDS

根据化学反应放热原理,以NaNO_2和NH_4Cl为生热剂,研制了自生热植物胶压裂液。本文报导自生热压裂液的生热产气原理及影响生热速度的因素,介绍了自生热压裂液的基本性能及现场应用情况。室内研究与现场试验结果表明,自生热压裂液具有明显的增产效果,适用于高凝稠油油藏的压裂改造。

Heat-generating aqueous plant gum hydrofracturing fluids (HFLs) arc prepared by incooperating highly cxothermic reaction mixture NaNO_2+NH_4Cl. It is shown that the rate of heat production and the maximum temperature reachable depend upon the ambinct temperature and the amount of catalist HCl-acid added. A heatgenerating HFL with pH=4 prepared from guar gum and ammonium persulfate has satisfactory theologic, filtration and friction reduction behavior and breaks down in 8 hrs at 60—90℃. The results of hydrofracturing oil wells by using heat-generating HFls are much better than that by using common HFLs owing to strong blownout and back flow after fractures being created. Heat-generating HFLs are useful for reservoirs of viscous crude and for wells of low flow rate.