摘要
研究塔里木盆地顺北油田4号断裂带凝析气藏中H_(2)S成因机制与富集过程。通过色谱法测定顺北4号断裂带多个井点的不同深度奥陶系气藏天然气样品的H_(2)S、CO_(2)含量,结合气藏干燥系数等指标,研究H_(2)S的地质成因,探讨其富集主控因素。结果表明:(1)奥陶系碳酸盐岩缝洞型凝析气藏普遍含H_(2)S,含量在0.3%~1.6%之间,达到单独估算H_(2)S气体储量的标准,具有较好的综合利用价值,且H_(2)S含量与CO_(2)含量具有正相关性,从南向北,含量逐渐减小,整体上为微—低含H_(2)S气藏;(2)顺北4号断裂带碳酸盐岩缝洞型凝析气藏的H_(2)S、CO_(2)为热化学硫酸盐还原反应(thermochemical sulfate reduction,TSR)产物,深部中寒武统广泛分布的膏盐岩为H_(2)S生成提供了物质基础,寒武系盐下形成的油气藏为TSR作用提供烃类,其长期深埋增温为TSR形成提供有利条件;(3)走滑断裂为深部H_(2)S向奥陶系油气藏的运移聚集提供通道,上奥陶统巨厚泥岩为含H_(2)S气藏的富集提供了良好的保存条件。即寒武系膏盐岩、走滑断裂沟通、上奥陶统严密封盖、晚期深埋高温等地质因素,共同造就了顺北东部奥陶系凝析气藏H_(2)S的富集,预示着顺北地区深层寒武系存在高含H_(2)S气藏。
This study investigates the origin and enrichment process of hydrogen sulfide in the condensate gas reservoirs of the Shunbei No.4 fault zone in the Tarim Basin.Gas samples from Ordovician gas reservoirs at different depths in Well Shunbei No.4 were analyzed by chromatographic method to determine hydrogen sulfide and carbon dioxide concentrations.The geological origins of hydrogen sulfide were studied,and its controlling factors of enrichment were discussed.The results show that:(1)The fracturedcavity type condensate gas reservoirs from the Ordovician carbonates generally contain hydrogen sulfide,with concentrations ranging from 0.3%to 1.6%,which meets the standard of estimating hydrogen sulfide gas reserves and has good comprehensive utilization value.Moreover,the hydrogen sulfide concentrations positively correlate with the carbon dioxide concentrations,decreasing from south to north,indicating a low-sulfur hydrogen gas reservoir.(2)Hydrogen sulfide and carbon dioxide of the carbonate fracture-type in condensate gas reservoirs of the Shunbei No.4 fault zone are products of thermochemical sulfate reduction(TSR).The deep,widely distributed Middle Cambrian salt rock provides the material basis for hydrogen sulfide generation,while hydrocarbon reservoirs formed in Cambrian subsalt strata provide hydrocarbons for the TSR process.The long-term increase in temperature due to the deep burial of Cambrian subsalt oil and gas reservoirs has created favorable conditions for the TSR process.(3)Strike-slip faults function as migration pathways for deep hydrogen sulfide into the Ordovician reservoirs.The thick Upper Ordovician mudstone provides excellent preservation conditions for the enrichment of hydrogen sulfide gas reservoirs.Consequently,geological factors such as Cambrian salt-rock,strik-slip fault connections,Upper Ordovician tight sealing and late-stage deep burial with high temperature have contributed to the enrichment of hydrogen sulfide in the Ordovician condensate gas reservoirs in eastern Shunbei,indicating the potential existence of high hydrogen sulfide gas reservoirs in deep Cambrian reservoirs of the Shunbei area.
作者
徐征遥
韩强
贾星亮
杨红彩
卜旭强
XU Zhengyao;HAN Qiang;JIA Xingliang;YANG Hongcai;BU Xuqiang(Experimental Testing Technology Center of Northwest Oilfield Branch Company,SINOPEC,Urumqi 830011,China;Research Institute of Exploration and Exploitation,SINOPEC Northwest Company,Urumqi 830011,China)
出处
《沉积与特提斯地质》
北大核心
2025年第2期305-316,共12页
Sedimentary Geology and Tethyan Geology
基金
“十三五”国家重大科技专项(2016ZX05005-004)
中国石化科技部项目(P21085-8,P23244)。
