辽河油田超稠油SAGD开发中H_2S成因分析

Genesis of H_2S Generated During Extra-heavy Oil Development in Liaohe Oilfield

通过监测辽河油田A区块套管气中H_2S的体积分数,分析原油、油砂、油田水、注入水及其化学处理剂的化学组分与矿物组成,开展H_2S生成热模拟实验,对超稠油热力开发中H_2S的成因进行研究。研究结果表明:研究区开发井中的H_2S是稠油热力开采的次生产物,其硫元素来源于油藏中分散的FeS和次生黄铁矿,开采过程中的热力作用为FeS和黄铁矿的富集与分解提供了能量并创造了化学热力学条件,其氢元素来源于地层水;研究区热采次生H_2S的产量主要受油藏(层位、区块)控制,油藏的FeS和次生黄铁矿潜力制约H_2S的生成潜力;热力开采为H_2S的产生提供物理条件,其持续时间和油藏温度等因素决定着H_2S的产生速率。

By monitoring H2S content in the pipelines at A block of Liaohe Oilfield, the chemical and mineral com- position is analyzed in oils, oilsand cores, oilfield water, water in steam generation procedures and the chemical additives, and H2S generation simulation experiments are carried out to study the genesis of hydrogen sulfide in the thermal development of super heavy oil. According to the results of the experiments, the H2S is a by - product of the thermal developmemt of heavy 0il and is generated from FeS and secondary pyrites in the oil reservoir. The en- gineering thermal process provides energy for the accumulation of FeS and for decomposing it to H2S, and the the hydrogen of H2S is taking from the reservoir water. The yield of H2S of the district is mainly subjected to the geo- logical condintion of the oil reservvoir, such as the formation and the district of the reservoir, whose FeS and py- rite amount control the yield of H2S pertential. And the thermal development provides physical condition for H2S generation, and the time it lasts and the temperature of the 0il production chamber it reaches control the H2S pro- duction rate.