Targeted viscosity reduction for chemical cold recovery of heavy oil: technologies and field cases
稠油化学冷采靶向降黏关键技术与应用

摘要

稠油作为我国重要的战略资源，其高黏度特性导致开发难度大。传统热采技术存在能耗高（350℃蒸汽）、碳排放量大、成本高等问题，且易引发汽窜、水侵等工程难题。针对这些技术瓶颈，本研究系统开展了稠油化学冷采靶向降黏关键技术攻关。通过高分辨率质谱和分子动力学模拟，首次量化了稠油中π-π堆积和氢键的黏度贡献率（占比超60%），并据此设计出多巴胺-酰胺基-苯磺酸基三元共聚双靶点降黏剂，实现稠油本体降黏率>80%。创新提出微粒自组装调堵机制，开发羟甲基丙烯酰胺-顺丁烯二酸-癸烯醇三元共聚调堵剂，解决了降黏剂靶向输送难题（粒径调控范围0.1μm~2mm）。首创井下交变水动力场注入技术，研制脉冲发生器（脉冲能量18kW），使药剂注入效率提升3倍。在胜利油田陈371-平X井应用中，吨药剂换油率达1:81.5，较热采蒸汽换油率（1:0.74）提升110倍，累计增产原油0.74万吨，碳排放减少60%。研究成果被纳入国家先进技术目录，并形成行业标准，为稠油绿色开发提供重要技术支撑。

Abstract

Heavy oil, as a strategic resource in China, presents significant development challenges due to its high viscosity. Conventional thermal recovery technologies suffer from high energy consumption (350°C steam), substantial carbon emissions, elevated costs, and engineering issues such as steam channeling and water encroachment. To address these technical bottlenecks, this study systematically investigated key technologies for targeted viscosity reduction in heavy oil cold chemical recovery. Through high-resolution mass spectrometry and molecular dynamics simulations, the viscosity contribution rates of π-π stacking and hydrogen bonding in heavy oil were quantified for the first time (exceeding 60%). Based on these findings, a dopamine-amide-benzene sulfonic acid ternary copolymer dual-target viscosity reducer was designed, achieving a bulk viscosity reduction rate of >80%. An innovative self-assembling particle plugging mechanism was proposed, leading to the development of a hydroxymethylacrylamide-maleic acid-decenol ternary copolymer plugging agent, which resolved the challenge of targeted delivery for viscosity reducers (adjustable particle size range: 0.1 μm-2 mm). A groundbreaking downhole alternating hydrodynamic field injection technology was pioneered, with the invention of a pulse generator (pulse energy: 18 kW) that tripled chemical injection efficiency. Field applications at Well Chen 371-Ping 14 in the Shengli Oilfield demonstrated remarkable results: the chemical-to-oil ratio reached 1:81.5, representing a 110-fold improvement over the steam-to-oil ratio (1:0.74) of thermal methods, with cumulative incremental oil production of 7400 tons and a 60% reduction in carbon emissions. The research outcomes have been included in the National Advanced Technology Catalog and established as industry standards, providing critical technical support for the green development of heavy oil resources.