摘要
针对低渗透稠油油藏渗流阻力大、注入能力差等问题，提出以化学生热剂和裂解催化剂组成复合降黏体系实现井下双效降黏的开发技术。室内通过高压反应釜实验优选了化学生热剂的反应条件和裂解催化剂的种类，并通过岩心驱替实验评了化学剂不同注入方式下的驱油效果和注入能力。研究结果表明：以pH=2，200 mL等体积摩尔浓度均为4 mol/L的NaNO2溶液和NH4Cl溶液组成的化学生热体系具有最佳的反应条件，对于500毫升的高温高压反应釜在反应6 min后可达到温度峰值204℃和压力峰值13.4 MPa，相对于初始条件升温149℃；以油酸镍(主催化剂)、7%甲酸（供氢体）、7%尿素（助剂）及0.13%十二烷基苯磺酸钠（乳化剂）组成的催化体系具有最高的降黏率，对牛圈湖油田地面脱气原油的降黏率可达65.3%；五种不同的注入方式中，水驱、化学生热交替驱(先注NaNO2)、化学生热交替驱(先注酸性NH4Cl)、化学生热焖井间歇驱、化学生热催化裂解焖井间歇驱采收率分别为30.6%，38.8%，40.8%，43.7%，49.0%，化学生热催化热裂解焖井间歇驱采收率最高，注入能力最佳，驱油能量最足，比水驱提高采收率18.4%。
Abstract
Aimed at the problems of high filtrational resistance and low injection capacity in the development of high viscosity oil reservoirs with low permeability, the complex viscosity reducing system, composed of chemical heat generating agent and catalytic cracking agent, was proposed to reduce oil viscosity and improve oil recovery of the type oil reservoir. Laboratory experiment was conducted in high-temperature and high-pressure (HTHP) reaction kettle to optimize reaction conditions and catalytic agent type, and then the core flooding experiment was conducted to evaluate the effects of injection mode on the oil recovery and the injection capacity. The results showed that when the 200 mL of the NaNO2 solution with molar concentration of 4 mol/L reacted with 200 mL of the NH4Cl solution with molar concentration of 4 mol/L at the pH value of 2 in the reaction kettle with 400 mL volume, the temperature in the reaction kettle increased from 55℃ to 204℃, pressure increased from 10 MPa to 13.4 MPa after reacting for 6 min. The catalytic system, composited of oleic acid nickel (main catalytic agent), 7% formic acid (hydrogen donor), 7% urea (adjuvant) and 0.13% sodium dodecyl benzene sulfonate( emulsifier), could decrease the viscosity of the stock tank oil from Niujuanhu oil field by 65.3%. The oil recovery of water flooding, NaNO2 and NH4Cl alternating flooding, NH4Cl and NaNO2 alternating flooding, chemical heat generating and soaking interval flooding, and chemical heat generating and catalytic cracking and soaking interval flooding were 30.6%, 38.8%, 40.8%, 43.7% and 49.0%, respectively. Therefore, chemical heat generating and catalytic cracking and soaking interval flooding was the best injection mode, which could enhence oil recovery by 18.4% based on the water flooding.
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