准噶尔盆地南缘井筒堵塞物中沥青质分子组成研究

采用傅里叶变换离子回旋共振质谱分析技术，分析了准噶尔盆地南缘高探1井原油及井筒堵塞物抽提物中沥青质化学组成及差异，探讨了沥青质的组成及结构与沥青质沉积关系，对于沥青质聚集理论研究具有重要意义。研究结果显示，高探1井原油及井筒堵塞物抽提物中沥青质分子主要为N₁、N₁O₁、O₁、O₂、O₃和O₄类化合物，但堵塞物抽提物中沥青质缩合度(DBE)明显高于原油中沥青质，具有更多的环烷和芳环结构，且富集O₂、O₃和O₄类化合物，表明地层原油在井筒流动过程中不同组成的沥青质具有一定的选择性。高缩合度沥青质组分优先析出，形成固体母核，其中多氧杂原子具有极强的极性，加速原油中其他沥青质组分的沉淀，从而形成堵塞物。另外，堵塞物抽提物中沥青质分子结构复杂，具有较宽的缩合度分布范围，DBE主要分布在9～30，其分子极性力参数较大，且分布范围宽，因此选取分子极性力参数相近的混合溶剂去除堵塞物较为理想。 

Molecular composition of asphaltene in wellbore blockage on the southern margin of Junggar Basin

Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) was employed to analyze the compositional differences of asphaltene of oil and blockage extracts of well Gaotan 1 on the southern margin of Junggar Basin. The correlation between asphaltene composition and structure and precipitation was discussed, which is important for the research of asphaltene precipitation and accumulation. Results showed that the asphaltene molecules of oil and blockage extracts of well Gaotan 1 are mainly composed of N₁, N₁O₁, O₁, O₂, O₃ and O₄ class species. However, the degree of asphaltene condensation in blockage extract is significantly higher than that in oil, and it is enriched with O₂, O₃ and O₄ class species. It indicates that during the flow of formation crude oil in wellbore, the precipitation of asphaltenes with different compositions has a certain selectivity. Asphaltene components with high condensation degree preferentially precipitate and deposit, forming a solid core. Among them, polyoxo-heteroatom compounds have relative strong polarity, which accelerates the precipitation of other asphaltene components in crude oil to form blockage. Asphaltene in blockage extract has a complex molecular structure and a wide range of condensation degree. The DBE values distribute between 9 and 30. Its molecular polar force parameter is larger and the distribution range is wider. Therefore, it is ideal to select a mixed solvent similar to the polar force parameter of blockage asphaltene to remove blockage.