Abstract:

When crude oil is extracted from oil wells, associated gas will be generated, and natural gas hydrates will be generated in high pressure and low temperature environments, which will block the transportation pipeline. Therefore, it is of great significance to study the hydrate formation in oil sand system (that is, the crude oil?containing system) and the pure quartz sand system (not including crude oil). The formation of methane hydrate and the final gas consumption in the oil sand system) and the pure quartz sand system were studied under the conditions of initial pressure of 4.00, 6.00, 8.00 MPa, quartz sand particle size of 20, 30, 60, 80 mesh, and constant temperature.The results show that in the oil sand system and under the same initial pressure conditions, the smaller the particle size of quartz sand, the shorter the induction period for hydrate formation, and the greater the rate of hydrate formation; the effect of particle size on the final gas consumption for hydrate formation It is found that as the particle size of the quartz sand decreases, the gas consumption first increases and then decreases. When the particle size of the quartz sand is 60 mesh, the gas consumption reaches the maximum, and its value is 0.19 mol. At the same time, the hydrate formation in the oil sand system and the pure quartz sand system was compared. The results show that, due to the presence of SDS (sodium dodecyl sulfate) solutions in the two systems, there is little difference in the formation rate of hydrates; the final gas consumption in the oil sand system is less than that in the quartz sand system under the same quartz sand particle size. This indicates that crude oil has an inhibitory effect on the formation of hydrates. In the oil sand system, it is found that the higher the pressure, the more favorable the formation of hydrates.

Key words: Oil sand, Quartz sand, Natural gas hydrate, Gas consumption

摘要：

在油井开采原油时，会产生伴生气，而在高压和低温环境中会生成天然气水合物，进而堵塞运输管道，因此研究油砂体系（含原油的体系）和纯石英砂体系（不含原油的体系）中水合物生成情况具有重要意义。在初始压力为4.00、6.00、8.00 MPa，石英砂粒径为20、30、60、80目，温度恒定的条件下，研究了油砂体系和纯石英砂体系中甲烷水合物的生成情况以及最终耗气量。结果表明，在初始压力相同的油砂体系中，石英砂粒径越小，水合物生成诱导期越短，水合物生成速率越大。研究石英砂粒径对水合物生成最终耗气量的影响发现，随着石英砂粒径的减小，耗气量先增加后减少，当石英砂粒径为60目时，耗气量达到最大，其值为0.19 mol。同时，对油砂体系和纯石英砂体系中水合物生成情况进行了对比。结果表明，由于两种体系中都存在SDS（十二烷基硫酸钠）溶液，因此水合物生成速率相差不大；在石英砂粒径相同的条件下，油砂体系中最终耗气量小于纯石英砂体系中的最终耗气量，这说明原油对水合物生成具有抑制作用。在油砂体系中，压力越大，越有利于水合物的生成。

关键词: 油砂, 石英砂, 天然气水合物, 耗气量