准噶尔盆地永进油田原油中沥青质固相析出影响机理研究

Influencing mechanisms of solid-phase asphaltene precipitation in crude oil of Yongjin Oil Field, Junggar Basin

杨阳 张东晓 王昊 伦增珉 高志卫 王锐 胡伟

YANG Yang ZHANG Dongxiao WANG Hao LUN Zengmin GAO Zhiwei WANG Rui HU Wei

北京大学 工学院, 北京 100871 中国石化 石油勘探开发研究院, 北京 100083 中石化新疆新春石油开发有限责任公司, 新疆 乌苏 834700

College of Engineering, Peking University, Beijing 100871, China Petroleum Exploration and Production Research Institute, SINOPEC, Beijing 100083, China Xinjiang Xinchun Petroleum Development Co., Ltd., SINOPEC, Wusu, Xinjiang 834700, China

在油藏开发过程中常见固态沥青质析出和沉积导致的储层伤害，及生产井堵塞问题，严重影响原油开采，降低开发经济效益。沥青质的固相析出与原油本身性质及温度/压力条件有关，是涉及气—液—固三相复杂相态的热力学问题。研究永进油田原油中沥青质的固相析出规律及其影响机理，可为合理避免开发过程中的沥青质沉积提供理论支撑。以永进油田高含沥青质原油为对象，通过原油组分分析、PVT高压物性分析、注气及沥青质固相析出实验，揭示了不同条件下的沥青质析出规律。基于立方体状态方程耦合缔合理论(CPA)，建立了油—气—沥青质三相相平衡计算模型，拟合了实验结果，进一步模拟了复杂条件下的沥青质析出规律，明确了流体组成、温度、压力及生产井工作制度对于沥青质固相析出的影响和机理。研究结果表明：流体组成和温度/压力条件分别是影响体系中沥青质析出的内在因素和外部条件，相似相容原理可以充分地解释沥青质的复杂相态变化机理；注气后改变了流体组成，对原油和沥青质相态的影响主要由注入气与原油的混相能力和对中间组分的萃取抽提能力决定；生产井工作制度则通过控制原油流动过程中的温度和压力变化从而影响沥青质的析出，决定了析出点的位置，对沥青质沉积堵塞风险的评价需要进一步结合油藏条件、井身结构和生产动态进行综合分析。

Solid-phase asphaltene precipitation and deposition, commonly occurring during reservoir development, lead to reservoir damage and production well blockage, seriously affecting crude oil exploitation and reducing economic efficiency. Solid-phase asphaltene precipitation is affected by the properties of crude oil and temperature/pressure condition, and is a thermodynamic issue involving complex gas-liquid-solid three-phase behavior. This study aims to investigate the solid-state precipitation pattern and its influencing mechanisms of asphaltenes in crude oil from the Yongjin Oil Field, aiming to provide theoretical support for the rational prevention of asphaltene deposition during reservoir development. High-asphaltene-content crude oil from the Yongjin Oil Field was selected as the research object. Crude oil composition analysis, pressure-volume-temperature (PVT) high-pressure physical property analysis, gas injection, and solid-phase asphaltene precipitation experiments were conducted to reveal the precipitation pattern of asphaltenes under different conditions. Based on the cubic plus association (CPA) equation of state (EoS), a three-phase equilibrium calculation model for the oil-gas-asphaltene system was established. The model was fitted to experimental results and used to further simulate the precipitation pattern of asphaltenes under complex conditions, clarifying the effects and their influencing mechanisms of fluid composition, temperature, pressure, and production well operation strategies on solid-phase asphaltene precipitation. The results showed that fluid composition and temperature/pressure conditions were the intrinsic factors and external conditions, respectively, influencing asphaltene precipitation in the system, and the like-dissolves-like principle could fully explain the mechanism of complex phase behavior changes in asphaltenes. After gas injection, the fluid composition was altered, and its influence on crude oil and asphaltene phase behavior was primarily determined by the miscibility of injected gas with crude oil and the extraction and stripping of intermediate components. Production well operation strategies affected asphaltene precipitation by controlling temperature and pressure variations during crude oil flow, thereby determining the location of precipitation. Risk assessment of asphaltene deposition and blockage requires comprehensive analysis integrating reservoir conditions, wellbore structure, and production dynamics.

国家自然科学基金企业创新发展联合基金集成项目“三大盆地深层—超深层海相油气高效勘探开发基础研究” U24B6001

https://doi.org/10.11781/sysydz2025040930