储层中原油裂解的模拟实验研究

发布时间：2018-02-01 14:41

本文关键词： 原油裂解生气热模拟实验储层介质环境 TSR 固体沥青飞仙关组鲕滩气藏　出处：《中国科学院研究生院(广州地球化学研究所)》2015年硕士论文　论文类型：学位论文

【摘要】：本论文采用生烃与碳同位素分馏动力学原理,结合有机地球化学中多种技术和方法(如生烃动力学模拟实验、气相色谱、气相色谱-同位素比值质谱等)深入研究探讨了储层环境中原油裂解过程中气态产物与固体沥青的地球化学特征。原油裂解模拟实验主要采用封闭黄金管-高压釜体系,在恒温(365℃)恒压(50MPa)加热方式下模拟不同储层介质环境下原油的裂解生气过程;模拟不同硫酸盐参与情况下的原油裂解,对生成的有机与无机气体进行产率与碳同位素分析,深入探讨了硫酸盐热化学还原反应(TSR)的机理。采用恒定升温速率(20℃/h、2℃/h)恒压(50MPa)加热方式开展封闭体系的原油热裂解模拟实验,同时对反应生成的气体、轻烃以及固体沥青残渣进行定量分析。通过实验与生烃动力学计算数据,建立原油裂解过程中固体沥青与原油裂解气产率的相关关系,并将该关系应用到实际地质条件下。结合川东北飞仙关组鲕滩气藏的地质参数与背景,提出一个基于储层固体沥青含量的评价方法并对飞仙关组存在大型气田的储层固体沥青含量下限进行了估算,可为预测该区古油藏的分布范围与规模以及现今油气藏的勘探开发提供科学依据。本论文主要获得如下成果与认识:1.在模拟实验条件下,水、矿物基质对原油裂解具有促进作用,使得气体产率有所提高,其中气态烃产率大约提高一倍,H2、CO2产率也有明显增加;2.硫酸镁溶液的存在可导致原油热解体系发生明显的硫酸盐热化学还原反应(TSR),产生大量H2S气体;同时烃类气体产率也有大幅提高,气体干燥系数明显增大;气体碳同位素数据表明TSR反应使甲烷、乙烷、丙烷相对富集13C。一定量氯化钠溶液的存在也会促进TSR反应,使得气态烃与非烃产率明显提高,同时造成烃类气体碳同位素组成的偏重(富集13C),乙烷的增重尤其明显,最大变化可达4‰。3.川东北飞仙关组鲕滩气藏储层固体沥青元素组成具有高S/C比、低H/C比的特点,固体碳同位素组成的分析对比表明飞仙关组鲕滩气藏天然气可能主要来源于下伏的上二叠统烃源岩;同时飞仙关组鲕滩气藏储层固体沥青反射率较高,具有较高的演化程度。表明川东北飞仙关组储层经历过高温埋藏过程,从而为川东北地区飞仙关组发生热化学硫酸盐还原反应提供地质条件。4.原油裂解过程中,固体沥青的生成起始于凝析油和湿气阶段(Easy Ro=1.0%~2.1%),并且在干气阶段大量产生(Easy Ro2.1%),表明固体沥青是原油在过成熟阶段的裂解产物。原油裂解过程中甲烷气与固体沥青的产量具有非常好的相关关系,由此关系式可建立固体沥青产量与甲烷产量转换率参数(CR)。据此对川东北飞仙关组存在大型气田的储层固体沥青含量下限进行了估算,初步结果显示固体沥青含量为1.22%可能是该地区圈定古油藏分布范围的一个重要参数。根据川东北地区高产量气藏的储层沥青含量等值线分布面积与油气藏储层的平面展布及储层沥青含量的分布趋势,可以对古油藏分布范围及规模进行预测;同时可对现今气藏的规模和分布进行预测,最终为我国深层海相天然气的评价与勘探提供实验依据及新的思路。
[Abstract]:This paper uses hydrocarbon and carbon isotope dynamics principle, combined with the organic geochemistry of various technologies and methods (such as hydrocarbon generation kinetics simulation experiment, gas chromatography, gas chromatography isotope ratio mass spectrometry) in-depth study of the geochemical characteristics of oil reservoir environment in the process of cracking gas products and solid bitumen. Oil cracking simulation experiment mainly adopts closed gold autovalve system, at a constant temperature (365 DEG C) constant pressure (50MPa) cracking crude oil reservoir in different medium environment generation process heating simulation; simulation of different sulfur acid salt in crude oil cracking conditions, analysis of yield and the carbon isotope of organic and inorganic gas generation the in-depth study of thermochemical sulfate reduction (TSR) mechanism. The constant heating rate (20 degrees /h, 2 degrees /h) constant pressure (50MPa) crude oil pyrolysis heating way to carry out the closed system At the same time, the simulation experiment, the reaction gas, light hydrocarbon and solid bitumen residue were quantitatively analyzed. The calculated data by experiment and kinetics of hydrocarbon generation, to build the relationship between the process of crude oil cracking in solid bitumen and crude oil cracking gas yield, and the relationship is applied to the actual geological conditions. Combined with the geological parameters of Feixianguan with the background of oolitic beach reservoir, a reservoir solid bitumen content evaluation method based on the reservoir solid bitumen content and lower limit of the Feixianguan formation has large gas fields were estimated, can provide a scientific basis for the distribution scope and scale prediction of the ancient oil reservoirs and the oil and gas exploration and development this paper mainly get the following results and understanding: 1. in the experiment conditions, water, mineral matrix has a promoting effect on crude oil cracking, the gas yield increased, the yields of gaseous hydrocarbon Approximately doubled H2, the yield of CO2 also increased significantly; 2. Magnesium Sulfate solution may lead to crude oil pyrolysis system has obvious thermochemical sulfate reduction reaction (TSR), a large amount of H2S gas; and hydrocarbon gas yield have significantly improved, gas drying coefficient significantly increased; carbon isotope data show that the TSR reaction. Methane, ethane, propane relative enrichment of 13C. certain amount of Sodium Chloride Solution's presence will also promote the TSR reaction, the gaseous hydrocarbon and non hydrocarbon yield increased significantly, while causing more hydrocarbon gas carbon isotope composition (rich in 13C), ethane weight obviously, the maximum change of up to 4.3.% of the oolitic beach gas reservoir solid bitumen composition with high S/C ratio and low H/C ratio, comparative analysis of solid carbon isotopic composition shows that the oolitic beach gas reservoirs may be mainly derived from the underlying. Two Permian source rocks; and oolitic beach reservoir solid bitumen reflectance high evolution degree is higher. That Feixianguan reservoir experienced buried high temperature process, which is in the northeast of Sichuan Feixianguan group occurred off the thermochemical sulfate reduction for the geological conditions of.4. crude oil in the process of cracking, generating solid bitumen starting in condensate oil and moisture stage (Easy Ro=1.0%~2.1%), and resulting in a large number of dry gas stage (Easy Ro2.1%), showed that the solid bitumen is in the mature stage of crude oil pyrolysis products. In process of crude oil cracking methane gas and solid bitumen production has good correlation. This relationship can be set up production and methane production in solid bitumen conversion rate parameter (CR). The reservoir solid bitumen content based on the lower limit of Feixianguan exist large gas fields were estimated, preliminary results show. The asphalt content of 1.22% may be an important parameter to delineate paleo oil reservoirs in the area. According to the distribution range of Northeast Sichuan high volume gas reservoir reservoir asphalt content isoline distribution area and the reservoir plane distribution and reservoir asphalt content distribution trend, we can predict the distribution of ancient oil reservoir at the same time and scale; the scale and distribution of the gas reservoir prediction, provide experimental basis and new ideas for our final evaluation and exploration of deep marine natural gas.

【学位授予单位】：中国科学院研究生院(广州地球化学研究所)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

【参考文献】