Abstract: Formation of H2S will bring great potential hazard to the safety of personnel and equipment in offshore oil fields. In order to determine the source of H2S in offshore heavy oil thermal recovery wells，the formation mechanism of H2S during thermal recovery development was investigated by conducting experiments. Simulated experimental study on the formation of H2S at different temperatures was carried out for the three reactions systems of heavy oil，heavy oil + distilled water，and heavy oil + water + core + methane. Besides， experiment was also conducted on the formation of H2S at high temperatures for sulfonate surfactant. The results show that for the heavy oil of Bohai S Oilfield，the concentration of H2S produced by the cracking and aquathermolysis of heavy oil increases with the increase in reaction temperature，and the organic gas produced is mostly the gas of light hydrocarbons below C5，with a small amount of C6+ gas. The aquathermolysis of heavy oil has caused the change in heavy oil composition. The contents of resin and asphaltene in heavy oil decrease，while the contents of saturated and aromatic components increase. This phenomenon becomes more obvious with the increase in reaction temperature. For the mixed system under study，at 200 ~ 300 ℃，aquathermolysis and TSR are dominant，which are the main sources of H2S；when the temperature reaches 350 ℃，cracking and TSR become dominant. At the same time，it is also found that it is very easy for sulfonate surfactant to produce H2S at high temperatures due to its instability at high temperatures. It is recommended that the use of sulfonate surfactant in the presence of steam be minimized in thermal recovery. 

Key words: hydrogen sulfide, thermochemical sulfate reduction, aquathermolysis, sulfonate surfactant, heavy oil thermal recovery

摘要： H2S的产生对海上油田现场作业人员和设备的安全均会带来巨大的隐患，为了确定海上稠油热采井H2S的来源，开 展了热采开发中H2S的生成机制探究实验。分别对稠油、稠油+蒸馏水、稠油+水+岩心+甲烷三种反应体系开展了不同温度 下生成H2S的模拟实验研究，并对磺酸盐类表面活性剂进行了高温条件下生成H2S实验。结果表明，对于渤海S油田稠油，稠 油热裂解和水热裂解产生H2S随着反应温度的升高，生成的H2S浓度逐渐增加，有机气体产量均以C5以下的轻烃气体为主， 含有少量C6+气体。稠油水热裂解反应引起了稠油组分变化，稠油的胶质和沥青质含量降低，饱和组分和芳香组分的含量 升高，且随着反应温度升高愈加明显。对所研究的混合体系，在200~300 ℃下，水热裂解、硫酸盐热化学还原（TSR）占据主 导地位，是主要的H2S来源；温度达到350 ℃，稠油裂解和TSR反应占据主导地位。同时研究发现磺酸盐表活剂因其高温不 稳定性等原因在高温条件下易产生H2S，建议在热采中减少磺酸盐表面活性剂的伴蒸汽使用。

关键词: 硫化氢；硫酸盐热化学还原；水热裂解反应；磺酸盐表面活性剂；稠油热采