摘要
文中运用天然气组分分析和轻烃色谱指纹特征对比等手段，查明了辽河油田S1区生产井泄漏气体的来源、成因及运移过程。研究认为：泄漏气体中烯烃、H2和CO等组分的存在，证实了该气体为稠油热采伴生气；泄漏气体的轻烃色谱指纹特征的前峰呈倒V形分布，后峰呈前低后高的V形分布，并且几乎不含有1，1￣二甲基环戊烷，这与馆陶组和兴隆台油层伴生气的轻烃色谱指纹特征相似，而与杜家台油层伴生气差异较大。跟踪监测发现，泄漏气体随着时间的推移，N2质量分数、干燥系数、丁烷系数下降，重烃组分C2+及CO2质量分数升高，具有水溶气脱溶特征，因此认为泄漏气体在向地面运移过程中，气体在油藏上覆地层水中经历了溶解—扩散—脱溶的过程。该研究为预防稠油热采开发过程中生产井气体泄漏的发生与针对性治理提供了技术支撑，对保障稠油油藏安全生产具有重要意义。
Abstract
The source, cause and migration process of gas leakage in the producing well in Block S1 of Liaohe Oilfield is found out by using composition analysis of natural gas and comparison of the chromatographic fingerprint characteristic of light hydrocarbons. According to the research, olefin, hydrogen, carbon monoxide and other components in the gas leakage prove that the gas is associated gas of heavy oil for thermal recovery. From the chromatographic fingerprint characteristic of light hydrocarbons, the former peak present a reverse "V" shaped distribution, and the latter peak present "V" shaped distribution with low ahead and high behind, barely containing any 1,1-dimethylcyclopentanone. This is similar to the fingerprint of associated gas in Guantao and Xinglongtai reservoirs, but quite different from that in Dujiatai. According to track monitoring, the N2 content, aridity coefficient and butane coefficient of the gas leakage reduce and the content of C2+ and CO2 increase over time, which have desolventizing characteristics of water-soluble gas. It is believed that during transport of the gas leakage towards ground, the gas experienced dissolution-diffusion-desolvation in the overlying formation water. The research serves as a technical support for the targeted treatment and prevention of gas leakage in production well in heavy oil thermal recovery. It is also of great significance to the safety production of heavy oil reservoir.
论文详情