火驱高温氧化特征判识方法研究

High-Temperature Oxidation Identification in Fire-Flooding

针对火驱地下高温氧化特征状态难以判识的问题,利用自主研制的火烧油层物理模拟装置,有针对性地开展了K039井天然岩心火驱物理模拟实验,研究不同温度、不同区带内尾气组分与原油性质变化规律,提出了氧气转化率、加氧程度、主峰碳、轻重比等火驱高温氧化特征判识方法。结果表明,当满足氧气转化率大于50.00%、加氧程度高于原始状态1倍、主峰碳前移、轻重比增大等条件时,火驱处于高温氧化阶段。将室内实验建立的判识指标应用于D66块取心井,分析表明,D66块火驱实现了高温氧化,纵向波及埋深为939.1~950.6 m,动用程度占火驱主力层段的40.3%,具有较大的调整潜力。该项研究可为火驱方案调整、生产动态调控提供技术支持。

A self-developed fire-flooding physical simulation device is used to identify the underground high-temperature regime during fire-flooding.The physical simulation of natural core samples from Well K039 is carried out to study the variation of tail gas composition and oil properties under different temperatures and zones.A series of methods for fire-flooding high-temperature oxidation identification are proposed,including oxygen conversion ratio,oxygenation level,main-peak carbon,light-heavy ratio,etc.Result shows that the fire-flooding steps into hightemperature oxidation regime when the oxygen conversion ratio exceeds 50%,the oxygenation level is 1 time higher than the original state,the main-peak carbon shifts forward ant the light-heavy ratio increases.These laboratory identification indicators are applied in the coring well of Block D66.Analysis indicates that the fire-flooding realizes high-temperature oxidation,the longitudinal sweep interval is 939.1 ~ 950.6 m,the producing level accounts for40.3% of major fire-flooding reservoir,which shows a great adjustment potential.This research could provide certain technical reference for the adjustments of fire-flooding program and production performance.