【作者】 葛云锦；

【导师】 周瑶琪； 陈勇；

【作者基本信息】 中国石油大学 ， 地质学， 2010， 博士

【摘要】 烃类包裹体在成矿、成藏等研究领域得到越来越广泛的重视,但是由于烃类包裹体成分和热力学行为的复杂性,其捕获条件的恢复及其捕获机制一直是一个难点,人工合成流体包裹体可以被用来研究包裹体的形成机制。本论文利用高温高压釜中人工愈合裂隙的方法,以方解石为主矿物,设计了10组不同目的的合成烃类包裹体实验,讨论了不同的油水比、温度、压力、盐度及原油性质对碳酸盐岩烃类包裹体捕获的影响,并通过显微测温、原位拉曼光谱、红外光谱和色谱等测试,获取合成包裹体温度、盐度、成分等参数,在此基础上分析了碳酸盐岩储层烃类包裹体的捕获机制以及其对油气运聚成藏的响应。首次在接近实际储层温压条件及纯油条件的实验中成功合成了烃类包裹体,是合成包裹体实验的新进展,带来了许多与油气成藏和储层地质学有关的新认识和重要启示。均一法测温发现由于压力差的存在,样品中盐水包裹体均一温度主要分布区间的平均值与实验设定温度即捕获温度存在一定差异,这个差值随着压力的变化而变化。利用合成的盐水包裹体均一温度与捕获温度的差异,建立了不同盐度条件下储层盐水包裹体均一温度校正曲线。应用热力学模拟软件与本文建立的储层盐水包裹体均一温度校正曲线相结合获取包裹体捕获温度压力是切实可行的。合成盐水包裹体的均一温度经过压力校正后得到的捕获温度压力忠实地反映了实验设定的温压条件,这说明储层中盐水包裹体能够记录其捕获时的温压条件。用冷冻法及拉曼光谱对盐水包裹体进行低温原位分析。冰点结果表明包裹体捕获的盐水溶液能够代表原始母液的盐度和成分。配置不同浓度的标准NaCl盐溶液进行实验,利用激光拉曼光谱在低温下测试NaCl-H2O体系溶液图谱。利用水合物特征峰值与冰峰值比和盐度之间的线性关系建立确定流体包裹体盐度的工作曲线。结合合成实验分析测试结果、储层多相渗流机制以及包裹体捕获条件恢复提出了均一条件下和非均一条件下烃类包裹体的捕获机制,均匀捕获又分油水共存(水主导)、油水共存(油主导)以及纯油条件三种情况。结合晶体生长理论提出了烃类包裹体的四种捕获模式:点模式、线模式、面模式及体模式。实验中出现加入一种原油而出现两种成熟度的烃类包裹体的情况,说明烃类包裹体捕获过程中的原油存在分馏,分馏机制可能有两种:物理机制,主要为色层效应;化学反应,原油发生裂解。实验模拟结果表明:油气饱和度增大对储层矿物的生长的抑制作用会增强,但并不会完全停止其生长。快速的油气成藏过程可以被油气包裹体记录下来。烃类流体包裹体可以记录油气成藏的整个过程,而不是含油饱和度较低的早期和晚期成藏过程。较高温度会产生酸性成岩环境,对方解石晶体产生溶蚀抑制其生长并捕获包裹体。温度较低时则可能会造成碱性成岩环境,促进方解石晶体的生长。相对于重质油来说,轻质油对方解石及石英晶体生长的抑制作用较强。较高盐度对晶体生长及包裹体捕获有利,但盐度过大反而会导致晶体生长速度减缓,因此只有在一定的盐度范围内,晶体的生长速度才是有效而合理的。针对合成包裹体均一温度的离散现象,探讨了包裹体的形状、大小及成分与其均一温度的关系。结果表明:包裹体的均一温度与包裹体的大小没有明显相关关系;形状较规则的包裹体较准确地反映其捕获温度的均一温度;包裹体的成分是影响包裹体均一温度的主要因素。在实际应用中应挑选形状较规则,气液比较为接近的一组包裹体进行测量,采用均一温度分布峰值进行研究,舍弃离散值。更多还原

【Abstract】 Hydrocarbon inclusions were valued in mineralise and petroleum area. But because the composition and thermodynamic behavior of hydrocarbon were complexity, there were some problems in recovery of capture condition and mechanism. Synthetic inclusions can be used to verified assumptions. In this paper, hydrocarbon inclusions were synthesized in calcite under high pressurem and temperature. Ten series of experiments with different aim were carried out in calcite. The effect of different oil/water ratios, temperature, pressure, salinity and distinct petroleum to hydrocarbon inclusion trapped in carbonate were disscussed. And microthermometry, Raman spectrum, infrared spectrum and chromatographic analysis were carried out on synthetic hydrocarbon inclusions to gain their homogenization temperature(Th), salinity, composition and phase transition. Based on these parameters, Trapping Mechanism of Hydrocabon Inclusion in Carbonate and Its Response to Hydrocarbon Accumulation were discussed.Synthetic hydrocarbon-bearing inclusions in carbonate at the temperature and pressure which were closed to natural reservoir and pure oil was new development of inclusion synthesized. Some new knowledge and inspiration about hydrocarbon accumulation and reservoir geology were bring out by the experiment.Through microthermometry, There were different between average of aqueous inclusions’Th in main distribution range and temperature set in experiment. Because the different was resulted from differential pressure, it was changed along with pressure changed. Using this different, calibration curve of aqueous inclusions with different salinity were established. Trapping condition of synthetic inclusions were resumed by using thermodynamic analogy software FIT and calibration curve,and which was coincidence with experimental pressure. After pressure correction, the trapping temperature and presssure of brine inclusions was coincidence with experimental condition, which demonstrated that brine inclusions could record their trapping conditions in reservoir.Freezing method and Raman spectrum were adopted to carry out low temperature in-situ measurement on aqueous inclusions. It was found from measurements that brine lixiviant trapped in inclusions was representative of original salinity and composition of mother solution. NaCl-H2O solution with different concentration were freezed for Raman spectrum measurement. The curve to define salinity of NaCl-H2O system was presented utilizing relationship between ratio of peak of hydrate and ice and salinity.Homogeneous and heterogenetic hydrocarbon trapping mechanism were present on the basis of experimental result, multiphase filtration mechanism in reservoir and recovery of inclusion trapping condition. Homogeneous trapping were classified as oil and water (oil dominance or water dominance) and pure oil condition. Combined with mechanism of crystal growth, four trapping model were presented. And they were point model, line model, area model and volume model.Because of composition differentiation of oil, two type degree of ripeness oil could be trapped in inclusions in experiment with one oil. And the differentiation mechanism could be divided as physical mechanism which was chromatograph and chemical mechanism which was pyrolysis of oil.Inclusions trapping would be constrained but not ceased by high O/W ratios. And inclusions could record rapid hydrocarbon accunulation. And the whole procedure of accunulation could be recorded in inclusions. The critical period of hydrocarbon charging correspond with great quantity of inclusions trapping. Relative high temperature could generate acid diagenetic environment which constrainted growth of calcite and inclusion trapped through denudation. In contrary, relative low temperature could generate alcaline diagenetic environment which accelerated growth of calcite. Inhibition of clean oil to growth of calcite was more intensive than that of heavy oil. higher salinity solution was favour of growth of calcite. But excessive salinity would slow down crystal growth. So crystal growth would be high efficient in particular salinity limit.The relationship between Th and composition, shape and size of inclusions synthized were discussed. Composition of inclusion was main affecting factor of its Th and there was no obvious relationship between shape and size and Th of inclusion. Inclusions with regulation shape and approximate gas/liquid ratios should be selected for thermometry. Adopt the peak of Th distribution range and abandon the discrete value.更多还原