自生热压裂生热剂用量优化方法

对于高凝、稠油油井的压裂,为避免注入流体对储层造成冷伤害,可采用自生热压裂液进行施工。自生热压裂液是在常规水基压裂液的基础上,添加一定量的亚硝酸钠、氯化铵和盐酸,当它们混合发生化学反应时,会释放出大量的热量。根据热平衡方程,建立自生热压裂过程中井筒温度场的数学模型,并编制出计算施工期间井底压裂液温度变化的软件,针对1口实际施工井,采用正交设计方法研究分析了影响生热剂用量的各种因素,提出了生热剂用量的优化确定方法。

Optimization Methods of Concentration of Heat- Generation Agents in In - Situ Heat Fracturing Treatment

During fracturing treatment of oil production wells with viscous crude and crude oil of high freezing point, it is suggested to adopt in situ heat fracturing liquids to avoid the cold damage to formation by injecting cold fluid. In situ heat fracturing liquids are made based on common water base fracturing liquids, with some NaNO\-2, NH\-4Cl and HCl added into the base fluid. When the additives are mixed and react, much heat will give out. A mathematical model of wellbore temperature profiles during in situ heat fracturing treatment based on heat balance equation is established in this paper, and a computing software was developed. Finally based on a case history of Liaohe oilfield, the effect of surface injection temperature, injection rate and concentration of catalytic agent on concentration of heat generation agents was investigated by means of orthogonalizing design technique, and developed optimization methods on concentration of heat generation agents in in situ heat fracturing treatment.